Преглед изворни кода

Add qrcode from https://github.com/xMasterX/all-the-plugins

git-subtree-dir: qrcode
git-subtree-mainline: c7765dc411ca703b9c6023fdff9f229523cbb9ec
git-subtree-split: 084893ae411c28a231047a13d4c8f4a423a6fc07
Willy-JL пре 2 година
родитељ
комит
df46e65603

+ 30 - 0
qrcode/.github/workflows/release.yml

@@ -0,0 +1,30 @@
+name: Release
+
+on:
+  push:
+    tags:
+      - 'v[0-9]+.[0-9]+.[0-9]+'
+
+jobs:
+  build:
+    name: Build
+    runs-on: ubuntu-latest
+    steps:
+      - name: Checkout Flipper Zero Firmware
+        uses: actions/checkout@v3
+        with:
+          repository: 'flipperdevices/flipperzero-firmware'
+          ref: '0.74.2'
+          submodules: true
+      - name: Checkout
+        uses: actions/checkout@v3
+        with:
+          path: 'applications_user/qrcode_app'
+      - name: Build
+        run: ./fbt fap_qrcode
+      - name: Publish
+        uses: softprops/action-gh-release@v1
+        with:
+          files: build/f7-firmware-D/.extapps/qrcode.fap
+          generate_release_notes: true
+          fail_on_unmatched_files: true

+ 52 - 0
qrcode/.gitignore

@@ -0,0 +1,52 @@
+# Prerequisites
+*.d
+
+# Object files
+*.o
+*.ko
+*.obj
+*.elf
+
+# Linker output
+*.ilk
+*.map
+*.exp
+
+# Precompiled Headers
+*.gch
+*.pch
+
+# Libraries
+*.lib
+*.a
+*.la
+*.lo
+
+# Shared objects (inc. Windows DLLs)
+*.dll
+*.so
+*.so.*
+*.dylib
+
+# Executables
+*.exe
+*.out
+*.app
+*.i*86
+*.x86_64
+*.hex
+
+# Debug files
+*.dSYM/
+*.su
+*.idb
+*.pdb
+
+# Kernel Module Compile Results
+*.mod*
+*.cmd
+.tmp_versions/
+modules.order
+Module.symvers
+Mkfile.old
+dkms.conf

+ 1 - 0
qrcode/.gitsubtree

@@ -0,0 +1 @@
+https://github.com/xMasterX/all-the-plugins dev non_catalog_apps/flipperzero-qrcode

+ 21 - 0
qrcode/LICENSE

@@ -0,0 +1,21 @@
+MIT License
+
+Copyright (c) 2022 Bob Matcuk
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+SOFTWARE.

+ 230 - 0
qrcode/README.md

@@ -0,0 +1,230 @@
+# flipperzero-qrcode
+Display qrcodes on the [Flipper Zero]
+
+## Download
+Grab the latest `qrcode.fap` from [Releases].
+
+## Installation
+Copy the `qrcode.fap` file onto your [Flipper Zero] sd card in the `apps/Tools`
+directory. Then create a top level directory called `qrcodes` to store your
+qrcode files. This can be done using [qFlipper], for example, by
+draging-and-dropping `qrcode.fap` into `apps/Tools` and then navigating back to
+the top level (where the directories like `infrared` and `nfc` live), right
+click, and create a new folder called `qrcodes`.
+
+## Creating QR Codes
+qrcode files are simple text files with the extension `.qrcode`. This app will
+expect them to live in a top-level directory on your sd card called `qrcodes`.
+They should have the following content:
+
+```
+Filetype: QRCode
+Version: 0
+Message: your content here
+```
+
+qrcode v2 supports a newer format as well (the old format still works for
+backward compatibility, or, if you don't need the newer features, the app will
+read version "0" files faster):
+
+```
+Filetype: QRCode
+Version: 1
+QRMode: B
+QRVersion: 6
+QRECC: L
+Message: your content here
+Message: multi-line content is possible
+```
+
+In a version "1" file, the `QRMode`, `QRVersion`, and `QRECC` are optional
+(though, must be in that order if more than one are specified). The app will
+attempt to use the specified mode, version, and/or ECC, if the content will
+fit. Otherwise, it may select a different mode, version, and/or ECC. Keep
+reading to learn about the meaning of `QRMode`, `QRVersion`, and `QRECC`.
+
+Version "1" files also support multi-line content. Each line starting with
+`Message:` will be concatenated together with newline characters.
+
+My recommendation is to allow the app to select a mode, version, and ECC level
+for you and, then, if you find that your qrcode reader prefers specific
+settings, update the file appropriately.
+
+### Message Format
+qrcodes support 4 formats called "modes": numeric, alpha-numeric, binary, and
+kanji. Because of the limited screen real-estate on the [Flipper Zero], you'll
+want to pick the best mode for the data you are trying to display.
+
+If unspecified in the `.qrcode` file, the app will automatically detect the
+best mode to use based on the message content.
+
+#### Numeric Mode (QRMode: N)
+Consists of only numbers, nothing else. This mode can encode the most data and
+is useful for things like phone numbers. To use this mode, your message must
+_not_ contain non-numeric characters. For example, a message content of "(xxx)
+xxx-xxxx" can _not_ use numeric mode (it would require "binary" mode, in fact).
+Instead, your message should just be "xxxxxxxxxx".
+
+#### Alpha-Numeric Mode (QRMode: A)
+This mode can encode numbers, uppercase letters *only*, spaces, and the
+following symbols: `$%*+-./:`. This format _may_ be appropriate for urls, as
+long as you're only encoding the domain name and you remember to use uppercase
+letters (ex: `HTTP://EXAMPLE.COM`). If your url includes some path after the
+domain, you'll likely need to use binary mode because the paths are usually
+case-sensitive.
+
+A qrcode in alpha-numeric mode can encode ~40% less data than numeric mode.
+
+#### Binary Mode (QRMode: B)
+This mode is a little bit of a misnomer: binary mode simply means that the
+message will be encoded as 8-bit bytes. The qrcode standard stipulates that
+text will use ISO-8859-1 (also known as Latin-1) encoding, _not_ utf8 as would
+be the standard these days. However, _some_ readers _may_ automatically detect
+utf8. To be standard-compliant, that basically means you can only use Latin
+letters, numbers, and symbols.
+
+Multi-line messages will always be in binary mode, since the other modes cannot
+encode a newline character.
+
+A qrcode in binary mode can encode ~60% less data than numeric mode, and ~30%
+less than alpha-numeric.
+
+#### Kanji Mode (QRMode: K)
+This mode is unsupported, so I won't go into detail. A limitation of the
+underlying qrcode library that I'm using, unfortunately. If there's interest,
+perhaps I'll hack in support sometime.
+
+### QRVersion
+A qrcode's version specifies how "big" it is. Higher versions contain more
+"modules" (ie, the "pixels" that make up qrcodes) and, thus, can encode more
+data. A version 1 qrcode contains 21x21 modules, whereas a version 11 code (the
+largest the Flipper Zero can display) contains 61x61 modules. The modules of a
+version 1 code will be 3x3 pixels on the Flipper Zero screen; version 2 and 3
+qrcodes will each have 2x2 pixel modules; and version 4 through 11 qrcodes will
+have single pixel modules.
+
+If unspecified in the `.qrcode` file, the app will automatically select the
+lowest version that can contain all of the message content, given the mode
+selected in the previous step.
+
+### QRECC
+A qrcode's ECC level determines the qrcode's resilience to "damage". In the
+case of the Flipper Zero, "damage" might be a dirty screen, dead pixels, or
+even screen glare. Higher ECC modes are more resilient, but can contain less
+data. The ECC modes are Low, Medium, Quartile, and High and can be specified in
+the `.qrcode` file using the first letter (L, M, Q, and H).
+
+qrcode readers may have an easier time reading qrcodes with higher ECC levels,
+so, if unspecified in the `.qrcode` file, the app will select the highest ECC
+level that can contain all of the message content, given the qrcode mode and
+version selected in the previous steps.
+
+## Using the App
+The app is fairly straightforward. When it first starts, the file browser will
+automatically open to the `qrcodes` directory and display any `.qrcode` files.
+Select one using the arrow keys and the center button. The qrcode will display.
+If you push the right arrow, some stats will display: the qrcode "Version"; the
+ECC level; and the qrcode Mode (Numeric, Alpha-Numeric, Binary, or Kanji).
+
+While viewing the stats, you can select Version or ECC using the up and down
+arrows and the center button. You can then increase or decrease the Version or
+ECC using up and down and save your choice using the center buttton. This
+feature was mostly added for my own amusement and testing, but, theoretically,
+it may help a reader that's having trouble if the default ECC is less than the
+highest value ("H"): you can increase the Version by 1 and then set the ECC to
+"H". Whether or not this helps depends on the reader.
+
+You can hide the stats by pressing the left arrow.
+
+When you're done viewing the qrcode, press the back button to return to the
+file browser. If you push the back button in the file browser, the app will
+exit.
+
+I will ask that you temper your expectations: the Flipper Zero screen is small
+and many readers may have difficulty reading the qrcodes, especially if they
+are encoding a lot of data. However, I have successfully got my iPhone to read
+qrcodes encoding phone numbers, wifi info, and a url, all the way up to a
+version 11 qrcode (ie, the largest size the screen will fit).
+
+## Example: Wifi QRCodes
+Most phones can automatically connect to wifi networks from a qrcode. If you
+should like to encode your wifi's connection info into a qrcode, here's how
+you'd do it:
+
+```
+Filetype: QRCode
+Version: 0
+Message: WIFI:S:<ssid>;P:<password>;T:<encryption>;
+```
+
+Replace `<ssid>` with the name of your wifi, `<password>` with the password.
+`<encryption>` would be "WPA" or "WEP". If your wifi is open (no password),
+this can be "None" and you can remove `P:<password>;` from the message. If your
+wifi is hidden (ie, does not broadcast the ssid), you can add `H:true;` to the
+end.
+
+Note that if your ssid or password contain any of these characters: `\";,:`,
+you'll need to "escape" it by placing a backslash (`\`) before it.
+
+For example, if my ssid was "wifiball" and not broadcast, and the password was
+"pa$$:word" with WPA encryption, the message would be:
+
+```
+Message: WIFI:S:wifiball;P:pa$$\:word;T:WPA;H:true;
+```
+
+## Example: vCard
+Phones can scan [vCard] qrcodes to automatically add a contact to their address
+book. Starting with qrcode v2, multi-line qrcodes can be created, allowing you
+to create vCards!
+
+```
+Filetype: QRCode
+Version: 1
+Message: BEGIN:VCARD
+Message: VERSION:3.0
+Message: N:Smith;John
+Message: FN:John Smith
+Message: ADR;TYPE=dom,home,postal,parcel:;;123 Example St;Exampleton;CA;90210;
+Message: BDAY:1970-01-01
+Message: TEL;TYPE=pref,voice,msg,cell:+18005551212
+Message: END:VCARD
+```
+
+Check the [vCard] specification to learn about all of the fields and their
+values.
+
+## Building
+First, clone the [flipperzero-firmware] repo and then clone this repo in the
+`applications_user` directory:
+
+```bash
+git clone git@github.com:flipperdevices/flipperzero-firmware.git
+cd flipperzero-firmware/applications_user
+git clone git@github.com:bmatcuk/flipperzero-qrcode.git
+```
+
+Next, in the base of the [flipperzero-firmware] directory, run fbt:
+
+```bash
+./fbt fap_qrcode
+```
+
+This will automatically install dependencies and build the application. When it
+has finished building, the .fap will be in
+`build/f7-firmware-D/.extapps/qrcode.fap` (fbt output will tell you where to
+find the .fap, should it change in the future).
+
+## qrcode library
+This application uses the [QRCode] library by ricmoo. This is the same library
+that is in the lib directory of the flipper-firmware repo (which was originally
+included for a [now-removed demo app]), but modified slightly to fix some
+compiler errors and allow the explicit selection of the qrcode mode.
+
+[now-removed demo app]: https://github.com/flipperdevices/flipperzero-firmware/pull/160/files
+[flipperzero-firmware]: https://github.com/flipperdevices/flipperzero-firmware
+[Flipper Zero]: https://flipperzero.one/
+[QRCode]: https://github.com/ricmoo/QRCode
+[qFlipper]: https://docs.flipperzero.one/qflipper
+[Releases]: https://github.com/bmatcuk/flipperzero-qrcode/releases/latest
+[vCard]: https://www.evenx.com/vcard-3-0-format-specification

+ 19 - 0
qrcode/application.fam

@@ -0,0 +1,19 @@
+App(
+    appid="qrcode",
+    name="QR Code",
+    fap_version=(2,0),
+    fap_description="Display qrcodes",
+    fap_author="Bob Matcuk",
+    fap_weburl="https://github.com/bmatcuk/flipperzero-qrcode",
+    apptype=FlipperAppType.EXTERNAL,
+    entry_point="qrcode_app",
+    stack_size=2 * 1024,
+    cdefines=["APP_QRCODE"],
+    requires=[
+        "gui",
+        "dialogs",
+    ],
+    fap_category="Tools",
+    fap_icon="icons/qrcode_10px.png",
+    fap_icon_assets="icons",
+)

BIN
qrcode/icons/qrcode_10px.png


+ 956 - 0
qrcode/qrcode.c

@@ -0,0 +1,956 @@
+/**
+ * The MIT License (MIT)
+ *
+ * This library is written and maintained by Richard Moore.
+ * Major parts were derived from Project Nayuki's library.
+ *
+ * Copyright (c) 2017 Richard Moore     (https://github.com/ricmoo/QRCode)
+ * Copyright (c) 2017 Project Nayuki    (https://www.nayuki.io/page/qr-code-generator-library)
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+
+/**
+ *  Special thanks to Nayuki (https://www.nayuki.io/) from which this library was
+ *  heavily inspired and compared against.
+ *
+ *  See: https://github.com/nayuki/QR-Code-generator/tree/master/cpp
+ */
+
+#include "qrcode.h"
+
+#include <stdlib.h>
+#include <string.h>
+
+#if LOCK_VERSION == 0
+
+static const uint16_t NUM_ERROR_CORRECTION_CODEWORDS[4][40] = {
+    // 1,  2,  3,  4,  5,   6,   7,   8,   9,  10,  11,  12,  13,  14,  15,  16,  17,  18,  19,  20,  21,  22,  23,  24,   25,   26,   27,   28,   29,   30,   31,   32,   33,   34,   35,   36,   37,   38,   39,   40    Error correction level
+    {10,  16,  26,  36,  48,  64,   72,   88,   110,  130,  150,  176, 198, 216,
+     240, 280, 308, 338, 364, 416,  442,  476,  504,  560,  588,  644, 700, 728,
+     784, 812, 868, 924, 980, 1036, 1064, 1120, 1204, 1260, 1316, 1372}, // Medium
+    {7,   10,  15,  20,  26,  36,  40,  48,  60,  72,  80,  96,  104, 120,
+     132, 144, 168, 180, 196, 224, 224, 252, 270, 300, 312, 336, 360, 390,
+     420, 450, 480, 510, 540, 570, 570, 600, 630, 660, 720, 750}, // Low
+    {17,   28,   44,   64,   88,   112,  130,  156,  192,  224,  264,  308,  352,  384,
+     432,  480,  532,  588,  650,  700,  750,  816,  900,  960,  1050, 1110, 1200, 1260,
+     1350, 1440, 1530, 1620, 1710, 1800, 1890, 1980, 2100, 2220, 2310, 2430}, // High
+    {13,   22,   36,   52,   72,   96,   108,  132,  160,  192,  224,  260, 288,  320,
+     360,  408,  448,  504,  546,  600,  644,  690,  750,  810,  870,  952, 1020, 1050,
+     1140, 1200, 1290, 1350, 1440, 1530, 1590, 1680, 1770, 1860, 1950, 2040}, // Quartile
+};
+
+static const uint8_t NUM_ERROR_CORRECTION_BLOCKS[4][40] = {
+    // Version: (note that index 0 is for padding, and is set to an illegal value)
+    // 1, 2, 3, 4, 5, 6, 7, 8, 9,10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40    Error correction level
+    {1,  1,  1,  2,  2,  4,  4,  4,  5,  5,  5,  8,  9,  9,  10, 10, 11, 13, 14, 16,
+     17, 17, 18, 20, 21, 23, 25, 26, 28, 29, 31, 33, 35, 37, 38, 40, 43, 45, 47, 49}, // Medium
+    {1, 1, 1, 1,  1,  2,  2,  2,  2,  4,  4,  4,  4,  4,  6,  6,  6,  6,  7,  8,
+     8, 9, 9, 10, 12, 12, 12, 13, 14, 15, 16, 17, 18, 19, 19, 20, 21, 22, 24, 25}, // Low
+    {1,  1,  2,  4,  4,  4,  5,  6,  8,  8,  11, 11, 16, 16, 18, 16, 19, 21, 25, 25,
+     25, 34, 30, 32, 35, 37, 40, 42, 45, 48, 51, 54, 57, 60, 63, 66, 70, 74, 77, 81}, // High
+    {1,  1,  2,  2,  4,  4,  6,  6,  8,  8,  8,  10, 12, 16, 12, 17, 16, 18, 21, 20,
+     23, 23, 25, 27, 29, 34, 34, 35, 38, 40, 43, 45, 48, 51, 53, 56, 59, 62, 65, 68}, // Quartile
+};
+
+static const uint16_t NUM_RAW_DATA_MODULES[40] = {
+    //  1,   2,   3,   4,    5,    6,    7,    8,    9,   10,   11,   12,   13,   14,   15,   16,   17,
+    208,
+    359,
+    567,
+    807,
+    1079,
+    1383,
+    1568,
+    1936,
+    2336,
+    2768,
+    3232,
+    3728,
+    4256,
+    4651,
+    5243,
+    5867,
+    6523,
+    //   18,   19,   20,   21,    22,    23,    24,    25,   26,    27,     28,    29,    30,    31,
+    7211,
+    7931,
+    8683,
+    9252,
+    10068,
+    10916,
+    11796,
+    12708,
+    13652,
+    14628,
+    15371,
+    16411,
+    17483,
+    18587,
+    //    32,    33,    34,    35,    36,    37,    38,    39,    40
+    19723,
+    20891,
+    22091,
+    23008,
+    24272,
+    25568,
+    26896,
+    28256,
+    29648};
+
+// @TODO: Put other LOCK_VERSIONS here
+#elif LOCK_VERSION == 3
+
+static const int16_t NUM_ERROR_CORRECTION_CODEWORDS[4] = {26, 15, 44, 36};
+
+static const int8_t NUM_ERROR_CORRECTION_BLOCKS[4] = {1, 1, 2, 2};
+
+static const uint16_t NUM_RAW_DATA_MODULES = 567;
+
+#else
+
+#error Unsupported LOCK_VERSION (add it...)
+
+#endif
+
+static int max(int a, int b) {
+    if(a > b) {
+        return a;
+    }
+    return b;
+}
+
+/*
+static int abs(int value) {
+    if (value < 0) { return -value; }
+    return value;
+}
+*/
+
+static int8_t getAlphanumeric(char c) {
+    if(c >= '0' && c <= '9') {
+        return (c - '0');
+    }
+    if(c >= 'A' && c <= 'Z') {
+        return (c - 'A' + 10);
+    }
+
+    switch(c) {
+    case ' ':
+        return 36;
+    case '$':
+        return 37;
+    case '%':
+        return 38;
+    case '*':
+        return 39;
+    case '+':
+        return 40;
+    case '-':
+        return 41;
+    case '.':
+        return 42;
+    case '/':
+        return 43;
+    case ':':
+        return 44;
+    }
+
+    return -1;
+}
+
+/* static bool isAlphanumeric(const char *text, uint16_t length) { */
+/*     while (length != 0) { */
+/*         if (getAlphanumeric(text[--length]) == -1) { return false; } */
+/*     } */
+/*     return true; */
+/* } */
+
+/* static bool isNumeric(const char *text, uint16_t length) { */
+/*     while (length != 0) { */
+/*         char c = text[--length]; */
+/*         if (c < '0' || c > '9') { return false; } */
+/*     } */
+/*     return true; */
+/* } */
+
+// We store the following tightly packed (less 8) in modeInfo
+//               <=9  <=26  <= 40
+// NUMERIC      ( 10,   12,    14);
+// ALPHANUMERIC (  9,   11,    13);
+// BYTE         (  8,   16,    16);
+static char getModeBits(uint8_t version, uint8_t mode) {
+    // Note: We use 15 instead of 16; since 15 doesn't exist and we cannot store 16 (8 + 8) in 3 bits
+    // hex(int("".join(reversed([('00' + bin(x - 8)[2:])[-3:] for x in [10, 9, 8, 12, 11, 15, 14, 13, 15]])), 2))
+    unsigned int modeInfo = 0x7bbb80a;
+
+#if LOCK_VERSION == 0 || LOCK_VERSION > 9
+    if(version > 9) {
+        modeInfo >>= 9;
+    }
+#endif
+
+#if LOCK_VERSION == 0 || LOCK_VERSION > 26
+    if(version > 26) {
+        modeInfo >>= 9;
+    }
+#endif
+
+    char result = 8 + ((modeInfo >> (3 * mode)) & 0x07);
+    if(result == 15) {
+        result = 16;
+    }
+
+    return result;
+}
+
+typedef struct BitBucket {
+    uint32_t bitOffsetOrWidth;
+    uint16_t capacityBytes;
+    uint8_t* data;
+} BitBucket;
+
+/*
+void bb_dump(BitBucket *bitBuffer) {
+    printf("Buffer: ");
+    for (uint32_t i = 0; i < bitBuffer->capacityBytes; i++) {
+        printf("%02x", bitBuffer->data[i]);
+        if ((i % 4) == 3) { printf(" "); }
+    }
+    printf("\n");
+}
+*/
+
+static uint16_t bb_getGridSizeBytes(uint8_t size) {
+    return (((size * size) + 7) / 8);
+}
+
+static uint16_t bb_getBufferSizeBytes(uint32_t bits) {
+    return ((bits + 7) / 8);
+}
+
+static void bb_initBuffer(BitBucket* bitBuffer, uint8_t* data, int32_t capacityBytes) {
+    bitBuffer->bitOffsetOrWidth = 0;
+    bitBuffer->capacityBytes = capacityBytes;
+    bitBuffer->data = data;
+
+    memset(data, 0, bitBuffer->capacityBytes);
+}
+
+static void bb_initGrid(BitBucket* bitGrid, uint8_t* data, uint8_t size) {
+    bitGrid->bitOffsetOrWidth = size;
+    bitGrid->capacityBytes = bb_getGridSizeBytes(size);
+    bitGrid->data = data;
+
+    memset(data, 0, bitGrid->capacityBytes);
+}
+
+static void bb_appendBits(BitBucket* bitBuffer, uint32_t val, uint8_t length) {
+    uint32_t offset = bitBuffer->bitOffsetOrWidth;
+    for(int8_t i = length - 1; i >= 0; i--, offset++) {
+        bitBuffer->data[offset >> 3] |= ((val >> i) & 1) << (7 - (offset & 7));
+    }
+    bitBuffer->bitOffsetOrWidth = offset;
+}
+/*
+void bb_setBits(BitBucket *bitBuffer, uint32_t val, int offset, uint8_t length) {
+    for (int8_t i = length - 1; i >= 0; i--, offset++) {
+        bitBuffer->data[offset >> 3] |= ((val >> i) & 1) << (7 - (offset & 7));
+    }
+}
+*/
+static void bb_setBit(BitBucket* bitGrid, uint8_t x, uint8_t y, bool on) {
+    uint32_t offset = y * bitGrid->bitOffsetOrWidth + x;
+    uint8_t mask = 1 << (7 - (offset & 0x07));
+    if(on) {
+        bitGrid->data[offset >> 3] |= mask;
+    } else {
+        bitGrid->data[offset >> 3] &= ~mask;
+    }
+}
+
+static void bb_invertBit(BitBucket* bitGrid, uint8_t x, uint8_t y, bool invert) {
+    uint32_t offset = y * bitGrid->bitOffsetOrWidth + x;
+    uint8_t mask = 1 << (7 - (offset & 0x07));
+    bool on = ((bitGrid->data[offset >> 3] & (1 << (7 - (offset & 0x07)))) != 0);
+    if(on ^ invert) {
+        bitGrid->data[offset >> 3] |= mask;
+    } else {
+        bitGrid->data[offset >> 3] &= ~mask;
+    }
+}
+
+static bool bb_getBit(BitBucket* bitGrid, uint8_t x, uint8_t y) {
+    uint32_t offset = y * bitGrid->bitOffsetOrWidth + x;
+    return (bitGrid->data[offset >> 3] & (1 << (7 - (offset & 0x07)))) != 0;
+}
+
+// XORs the data modules in this QR Code with the given mask pattern. Due to XOR's mathematical
+// properties, calling applyMask(m) twice with the same value is equivalent to no change at all.
+// This means it is possible to apply a mask, undo it, and try another mask. Note that a final
+// well-formed QR Code symbol needs exactly one mask applied (not zero, not two, etc.).
+static void applyMask(BitBucket* modules, BitBucket* isFunction, uint8_t mask) {
+    uint8_t size = modules->bitOffsetOrWidth;
+
+    for(uint8_t y = 0; y < size; y++) {
+        for(uint8_t x = 0; x < size; x++) {
+            if(bb_getBit(isFunction, x, y)) {
+                continue;
+            }
+
+            bool invert = 0;
+            switch(mask) {
+            case 0:
+                invert = (x + y) % 2 == 0;
+                break;
+            case 1:
+                invert = y % 2 == 0;
+                break;
+            case 2:
+                invert = x % 3 == 0;
+                break;
+            case 3:
+                invert = (x + y) % 3 == 0;
+                break;
+            case 4:
+                invert = (x / 3 + y / 2) % 2 == 0;
+                break;
+            case 5:
+                invert = x * y % 2 + x * y % 3 == 0;
+                break;
+            case 6:
+                invert = (x * y % 2 + x * y % 3) % 2 == 0;
+                break;
+            case 7:
+                invert = ((x + y) % 2 + x * y % 3) % 2 == 0;
+                break;
+            }
+            bb_invertBit(modules, x, y, invert);
+        }
+    }
+}
+
+static void
+    setFunctionModule(BitBucket* modules, BitBucket* isFunction, uint8_t x, uint8_t y, bool on) {
+    bb_setBit(modules, x, y, on);
+    bb_setBit(isFunction, x, y, true);
+}
+
+// Draws a 9*9 finder pattern including the border separator, with the center module at (x, y).
+static void drawFinderPattern(BitBucket* modules, BitBucket* isFunction, uint8_t x, uint8_t y) {
+    uint8_t size = modules->bitOffsetOrWidth;
+
+    for(int8_t i = -4; i <= 4; i++) {
+        for(int8_t j = -4; j <= 4; j++) {
+            uint8_t dist = max(abs(i), abs(j)); // Chebyshev/infinity norm
+            int16_t xx = x + j, yy = y + i;
+            if(0 <= xx && xx < size && 0 <= yy && yy < size) {
+                setFunctionModule(modules, isFunction, xx, yy, dist != 2 && dist != 4);
+            }
+        }
+    }
+}
+
+// Draws a 5*5 alignment pattern, with the center module at (x, y).
+static void drawAlignmentPattern(BitBucket* modules, BitBucket* isFunction, uint8_t x, uint8_t y) {
+    for(int8_t i = -2; i <= 2; i++) {
+        for(int8_t j = -2; j <= 2; j++) {
+            setFunctionModule(modules, isFunction, x + j, y + i, max(abs(i), abs(j)) != 1);
+        }
+    }
+}
+
+// Draws two copies of the format bits (with its own error correction code)
+// based on the given mask and this object's error correction level field.
+static void drawFormatBits(BitBucket* modules, BitBucket* isFunction, uint8_t ecc, uint8_t mask) {
+    uint8_t size = modules->bitOffsetOrWidth;
+
+    // Calculate error correction code and pack bits
+    uint32_t data = ecc << 3 | mask; // errCorrLvl is uint2, mask is uint3
+    uint32_t rem = data;
+    for(int i = 0; i < 10; i++) {
+        rem = (rem << 1) ^ ((rem >> 9) * 0x537);
+    }
+
+    data = data << 10 | rem;
+    data ^= 0x5412; // uint15
+
+    // Draw first copy
+    for(uint8_t i = 0; i <= 5; i++) {
+        setFunctionModule(modules, isFunction, 8, i, ((data >> i) & 1) != 0);
+    }
+
+    setFunctionModule(modules, isFunction, 8, 7, ((data >> 6) & 1) != 0);
+    setFunctionModule(modules, isFunction, 8, 8, ((data >> 7) & 1) != 0);
+    setFunctionModule(modules, isFunction, 7, 8, ((data >> 8) & 1) != 0);
+
+    for(int8_t i = 9; i < 15; i++) {
+        setFunctionModule(modules, isFunction, 14 - i, 8, ((data >> i) & 1) != 0);
+    }
+
+    // Draw second copy
+    for(int8_t i = 0; i <= 7; i++) {
+        setFunctionModule(modules, isFunction, size - 1 - i, 8, ((data >> i) & 1) != 0);
+    }
+
+    for(int8_t i = 8; i < 15; i++) {
+        setFunctionModule(modules, isFunction, 8, size - 15 + i, ((data >> i) & 1) != 0);
+    }
+
+    setFunctionModule(modules, isFunction, 8, size - 8, true);
+}
+
+// Draws two copies of the version bits (with its own error correction code),
+// based on this object's version field (which only has an effect for 7 <= version <= 40).
+static void drawVersion(BitBucket* modules, BitBucket* isFunction, uint8_t version) {
+    int8_t size = modules->bitOffsetOrWidth;
+
+#if LOCK_VERSION != 0 && LOCK_VERSION < 7
+    return;
+
+#else
+    if(version < 7) {
+        return;
+    }
+
+    // Calculate error correction code and pack bits
+    uint32_t rem = version; // version is uint6, in the range [7, 40]
+    for(uint8_t i = 0; i < 12; i++) {
+        rem = (rem << 1) ^ ((rem >> 11) * 0x1F25);
+    }
+
+    uint32_t data = version << 12 | rem; // uint18
+
+    // Draw two copies
+    for(uint8_t i = 0; i < 18; i++) {
+        bool bit = ((data >> i) & 1) != 0;
+        uint8_t a = size - 11 + i % 3, b = i / 3;
+        setFunctionModule(modules, isFunction, a, b, bit);
+        setFunctionModule(modules, isFunction, b, a, bit);
+    }
+
+#endif
+}
+
+static void
+    drawFunctionPatterns(BitBucket* modules, BitBucket* isFunction, uint8_t version, uint8_t ecc) {
+    uint8_t size = modules->bitOffsetOrWidth;
+
+    // Draw the horizontal and vertical timing patterns
+    for(uint8_t i = 0; i < size; i++) {
+        setFunctionModule(modules, isFunction, 6, i, i % 2 == 0);
+        setFunctionModule(modules, isFunction, i, 6, i % 2 == 0);
+    }
+
+    // Draw 3 finder patterns (all corners except bottom right; overwrites some timing modules)
+    drawFinderPattern(modules, isFunction, 3, 3);
+    drawFinderPattern(modules, isFunction, size - 4, 3);
+    drawFinderPattern(modules, isFunction, 3, size - 4);
+
+#if LOCK_VERSION == 0 || LOCK_VERSION > 1
+
+    if(version > 1) {
+        // Draw the numerous alignment patterns
+
+        uint8_t alignCount = version / 7 + 2;
+        uint8_t step;
+        if(version != 32) {
+            step = (version * 4 + alignCount * 2 + 1) / (2 * alignCount - 2) *
+                   2; // ceil((size - 13) / (2*numAlign - 2)) * 2
+        } else { // C-C-C-Combo breaker!
+            step = 26;
+        }
+
+        uint8_t alignPositionIndex = alignCount - 1;
+        uint8_t alignPosition[alignCount];
+
+        alignPosition[0] = 6;
+
+        uint8_t size = version * 4 + 17;
+        for(uint8_t i = 0, pos = size - 7; i < alignCount - 1; i++, pos -= step) {
+            alignPosition[alignPositionIndex--] = pos;
+        }
+
+        for(uint8_t i = 0; i < alignCount; i++) {
+            for(uint8_t j = 0; j < alignCount; j++) {
+                if((i == 0 && j == 0) || (i == 0 && j == alignCount - 1) ||
+                   (i == alignCount - 1 && j == 0)) {
+                    continue; // Skip the three finder corners
+                } else {
+                    drawAlignmentPattern(modules, isFunction, alignPosition[i], alignPosition[j]);
+                }
+            }
+        }
+    }
+
+#endif
+
+    // Draw configuration data
+    drawFormatBits(
+        modules, isFunction, ecc, 0); // Dummy mask value; overwritten later in the constructor
+    drawVersion(modules, isFunction, version);
+}
+
+// Draws the given sequence of 8-bit codewords (data and error correction) onto the entire
+// data area of this QR Code symbol. Function modules need to be marked off before this is called.
+static void drawCodewords(BitBucket* modules, BitBucket* isFunction, BitBucket* codewords) {
+    uint32_t bitLength = codewords->bitOffsetOrWidth;
+    uint8_t* data = codewords->data;
+
+    uint8_t size = modules->bitOffsetOrWidth;
+
+    // Bit index into the data
+    uint32_t i = 0;
+
+    // Do the funny zigzag scan
+    for(int16_t right = size - 1; right >= 1;
+        right -= 2) { // Index of right column in each column pair
+        if(right == 6) {
+            right = 5;
+        }
+
+        for(uint8_t vert = 0; vert < size; vert++) { // Vertical counter
+            for(int j = 0; j < 2; j++) {
+                uint8_t x = right - j; // Actual x coordinate
+                bool upwards = ((right & 2) == 0) ^ (x < 6);
+                uint8_t y = upwards ? size - 1 - vert : vert; // Actual y coordinate
+                if(!bb_getBit(isFunction, x, y) && i < bitLength) {
+                    bb_setBit(modules, x, y, ((data[i >> 3] >> (7 - (i & 7))) & 1) != 0);
+                    i++;
+                }
+                // If there are any remainder bits (0 to 7), they are already
+                // set to 0/false/white when the grid of modules was initialized
+            }
+        }
+    }
+}
+
+#define PENALTY_N1 3
+#define PENALTY_N2 3
+#define PENALTY_N3 40
+#define PENALTY_N4 10
+
+// Calculates and returns the penalty score based on state of this QR Code's current modules.
+// This is used by the automatic mask choice algorithm to find the mask pattern that yields the lowest score.
+// @TODO: This can be optimized by working with the bytes instead of bits.
+static uint32_t getPenaltyScore(BitBucket* modules) {
+    uint32_t result = 0;
+
+    uint8_t size = modules->bitOffsetOrWidth;
+
+    // Adjacent modules in row having same color
+    for(uint8_t y = 0; y < size; y++) {
+        bool colorX = bb_getBit(modules, 0, y);
+        for(uint8_t x = 1, runX = 1; x < size; x++) {
+            bool cx = bb_getBit(modules, x, y);
+            if(cx != colorX) {
+                colorX = cx;
+                runX = 1;
+
+            } else {
+                runX++;
+                if(runX == 5) {
+                    result += PENALTY_N1;
+                } else if(runX > 5) {
+                    result++;
+                }
+            }
+        }
+    }
+
+    // Adjacent modules in column having same color
+    for(uint8_t x = 0; x < size; x++) {
+        bool colorY = bb_getBit(modules, x, 0);
+        for(uint8_t y = 1, runY = 1; y < size; y++) {
+            bool cy = bb_getBit(modules, x, y);
+            if(cy != colorY) {
+                colorY = cy;
+                runY = 1;
+            } else {
+                runY++;
+                if(runY == 5) {
+                    result += PENALTY_N1;
+                } else if(runY > 5) {
+                    result++;
+                }
+            }
+        }
+    }
+
+    uint16_t black = 0;
+    for(uint8_t y = 0; y < size; y++) {
+        uint16_t bitsRow = 0, bitsCol = 0;
+        for(uint8_t x = 0; x < size; x++) {
+            bool color = bb_getBit(modules, x, y);
+
+            // 2*2 blocks of modules having same color
+            if(x > 0 && y > 0) {
+                bool colorUL = bb_getBit(modules, x - 1, y - 1);
+                bool colorUR = bb_getBit(modules, x, y - 1);
+                bool colorL = bb_getBit(modules, x - 1, y);
+                if(color == colorUL && color == colorUR && color == colorL) {
+                    result += PENALTY_N2;
+                }
+            }
+
+            // Finder-like pattern in rows and columns
+            bitsRow = ((bitsRow << 1) & 0x7FF) | color;
+            bitsCol = ((bitsCol << 1) & 0x7FF) | bb_getBit(modules, y, x);
+
+            // Needs 11 bits accumulated
+            if(x >= 10) {
+                if(bitsRow == 0x05D || bitsRow == 0x5D0) {
+                    result += PENALTY_N3;
+                }
+                if(bitsCol == 0x05D || bitsCol == 0x5D0) {
+                    result += PENALTY_N3;
+                }
+            }
+
+            // Balance of black and white modules
+            if(color) {
+                black++;
+            }
+        }
+    }
+
+    // Find smallest k such that (45-5k)% <= dark/total <= (55+5k)%
+    uint16_t total = size * size;
+    for(uint16_t k = 0; black * 20 < (9 - k) * total || black * 20 > (11 + k) * total; k++) {
+        result += PENALTY_N4;
+    }
+
+    return result;
+}
+
+static uint8_t rs_multiply(uint8_t x, uint8_t y) {
+    // Russian peasant multiplication
+    // See: https://en.wikipedia.org/wiki/Ancient_Egyptian_multiplication
+    uint16_t z = 0;
+    for(int8_t i = 7; i >= 0; i--) {
+        z = (z << 1) ^ ((z >> 7) * 0x11D);
+        z ^= ((y >> i) & 1) * x;
+    }
+    return z;
+}
+
+static void rs_init(uint8_t degree, uint8_t* coeff) {
+    memset(coeff, 0, degree);
+    coeff[degree - 1] = 1;
+
+    // Compute the product polynomial (x - r^0) * (x - r^1) * (x - r^2) * ... * (x - r^{degree-1}),
+    // drop the highest term, and store the rest of the coefficients in order of descending powers.
+    // Note that r = 0x02, which is a generator element of this field GF(2^8/0x11D).
+    uint16_t root = 1;
+    for(uint8_t i = 0; i < degree; i++) {
+        // Multiply the current product by (x - r^i)
+        for(uint8_t j = 0; j < degree; j++) {
+            coeff[j] = rs_multiply(coeff[j], root);
+            if(j + 1 < degree) {
+                coeff[j] ^= coeff[j + 1];
+            }
+        }
+        root = (root << 1) ^ ((root >> 7) * 0x11D); // Multiply by 0x02 mod GF(2^8/0x11D)
+    }
+}
+
+static void rs_getRemainder(
+    uint8_t degree,
+    uint8_t* coeff,
+    uint8_t* data,
+    uint8_t length,
+    uint8_t* result,
+    uint8_t stride) {
+    // Compute the remainder by performing polynomial division
+
+    //for (uint8_t i = 0; i < degree; i++) { result[] = 0; }
+    //memset(result, 0, degree);
+
+    for(uint8_t i = 0; i < length; i++) {
+        uint8_t factor = data[i] ^ result[0];
+        for(uint8_t j = 1; j < degree; j++) {
+            result[(j - 1) * stride] = result[j * stride];
+        }
+        result[(degree - 1) * stride] = 0;
+
+        for(uint8_t j = 0; j < degree; j++) {
+            result[j * stride] ^= rs_multiply(coeff[j], factor);
+        }
+    }
+}
+
+static int8_t encodeDataCodewords(
+    BitBucket* dataCodewords,
+    const uint8_t* text,
+    uint16_t length,
+    int8_t mode,
+    uint8_t version) {
+    if(mode == MODE_NUMERIC) {
+        bb_appendBits(dataCodewords, 1 << MODE_NUMERIC, 4);
+        bb_appendBits(dataCodewords, length, getModeBits(version, MODE_NUMERIC));
+
+        uint16_t accumData = 0;
+        uint8_t accumCount = 0;
+        for(uint16_t i = 0; i < length; i++) {
+            accumData = accumData * 10 + ((char)(text[i]) - '0');
+            accumCount++;
+            if(accumCount == 3) {
+                bb_appendBits(dataCodewords, accumData, 10);
+                accumData = 0;
+                accumCount = 0;
+            }
+        }
+
+        // 1 or 2 digits remaining
+        if(accumCount > 0) {
+            bb_appendBits(dataCodewords, accumData, accumCount * 3 + 1);
+        }
+
+    } else if(mode == MODE_ALPHANUMERIC) {
+        bb_appendBits(dataCodewords, 1 << MODE_ALPHANUMERIC, 4);
+        bb_appendBits(dataCodewords, length, getModeBits(version, MODE_ALPHANUMERIC));
+
+        uint16_t accumData = 0;
+        uint8_t accumCount = 0;
+        for(uint16_t i = 0; i < length; i++) {
+            accumData = accumData * 45 + getAlphanumeric((char)(text[i]));
+            accumCount++;
+            if(accumCount == 2) {
+                bb_appendBits(dataCodewords, accumData, 11);
+                accumData = 0;
+                accumCount = 0;
+            }
+        }
+
+        // 1 character remaining
+        if(accumCount > 0) {
+            bb_appendBits(dataCodewords, accumData, 6);
+        }
+
+    } else {
+        bb_appendBits(dataCodewords, 1 << MODE_BYTE, 4);
+        bb_appendBits(dataCodewords, length, getModeBits(version, MODE_BYTE));
+        for(uint16_t i = 0; i < length; i++) {
+            bb_appendBits(dataCodewords, (char)(text[i]), 8);
+        }
+    }
+
+    //bb_setBits(dataCodewords, length, 4, getModeBits(version, mode));
+
+    return mode;
+}
+
+static void performErrorCorrection(uint8_t version, uint8_t ecc, BitBucket* data) {
+    // See: http://www.thonky.com/qr-code-tutorial/structure-final-message
+
+#if LOCK_VERSION == 0
+    uint8_t numBlocks = NUM_ERROR_CORRECTION_BLOCKS[ecc][version - 1];
+    uint16_t totalEcc = NUM_ERROR_CORRECTION_CODEWORDS[ecc][version - 1];
+    uint16_t moduleCount = NUM_RAW_DATA_MODULES[version - 1];
+#else
+    uint8_t numBlocks = NUM_ERROR_CORRECTION_BLOCKS[ecc];
+    uint16_t totalEcc = NUM_ERROR_CORRECTION_CODEWORDS[ecc];
+    uint16_t moduleCount = NUM_RAW_DATA_MODULES;
+#endif
+
+    uint8_t blockEccLen = totalEcc / numBlocks;
+    uint8_t numShortBlocks = numBlocks - moduleCount / 8 % numBlocks;
+    uint8_t shortBlockLen = moduleCount / 8 / numBlocks;
+
+    uint8_t shortDataBlockLen = shortBlockLen - blockEccLen;
+
+    uint8_t result[data->capacityBytes];
+    memset(result, 0, sizeof(result));
+
+    uint8_t coeff[blockEccLen];
+    rs_init(blockEccLen, coeff);
+
+    uint16_t offset = 0;
+    uint8_t* dataBytes = data->data;
+
+    // Interleave all short blocks
+    for(uint8_t i = 0; i < shortDataBlockLen; i++) {
+        uint16_t index = i;
+        uint8_t stride = shortDataBlockLen;
+        for(uint8_t blockNum = 0; blockNum < numBlocks; blockNum++) {
+            result[offset++] = dataBytes[index];
+
+#if LOCK_VERSION == 0 || LOCK_VERSION >= 5
+            if(blockNum == numShortBlocks) {
+                stride++;
+            }
+#endif
+            index += stride;
+        }
+    }
+
+    // Version less than 5 only have short blocks
+#if LOCK_VERSION == 0 || LOCK_VERSION >= 5
+    {
+        // Interleave long blocks
+        uint16_t index = shortDataBlockLen * (numShortBlocks + 1);
+        uint8_t stride = shortDataBlockLen;
+        for(uint8_t blockNum = 0; blockNum < numBlocks - numShortBlocks; blockNum++) {
+            result[offset++] = dataBytes[index];
+
+            if(blockNum == 0) {
+                stride++;
+            }
+            index += stride;
+        }
+    }
+#endif
+
+    // Add all ecc blocks, interleaved
+    uint8_t blockSize = shortDataBlockLen;
+    for(uint8_t blockNum = 0; blockNum < numBlocks; blockNum++) {
+#if LOCK_VERSION == 0 || LOCK_VERSION >= 5
+        if(blockNum == numShortBlocks) {
+            blockSize++;
+        }
+#endif
+        rs_getRemainder(
+            blockEccLen, coeff, dataBytes, blockSize, &result[offset + blockNum], numBlocks);
+        dataBytes += blockSize;
+    }
+
+    memcpy(data->data, result, data->capacityBytes);
+    data->bitOffsetOrWidth = moduleCount;
+}
+
+// We store the Format bits tightly packed into a single byte (each of the 4 modes is 2 bits)
+// The format bits can be determined by ECC_FORMAT_BITS >> (2 * ecc)
+static const uint8_t ECC_FORMAT_BITS = (0x02 << 6) | (0x03 << 4) | (0x00 << 2) | (0x01 << 0);
+
+uint16_t qrcode_getBufferSize(uint8_t version) {
+    return bb_getGridSizeBytes(4 * version + 17);
+}
+
+// @TODO: Return error if data is too big.
+int8_t qrcode_initBytes(
+    QRCode* qrcode,
+    uint8_t* modules,
+    int8_t mode,
+    uint8_t version,
+    uint8_t ecc,
+    uint8_t* data,
+    uint16_t length) {
+    uint8_t size = version * 4 + 17;
+    qrcode->version = version;
+    qrcode->size = size;
+    qrcode->ecc = ecc;
+    qrcode->modules = modules;
+
+    uint8_t eccFormatBits = (ECC_FORMAT_BITS >> (2 * ecc)) & 0x03;
+
+#if LOCK_VERSION == 0
+    uint16_t moduleCount = NUM_RAW_DATA_MODULES[version - 1];
+    uint16_t dataCapacity =
+        moduleCount / 8 - NUM_ERROR_CORRECTION_CODEWORDS[eccFormatBits][version - 1];
+#else
+    version = LOCK_VERSION;
+    uint16_t moduleCount = NUM_RAW_DATA_MODULES;
+    uint16_t dataCapacity = moduleCount / 8 - NUM_ERROR_CORRECTION_CODEWORDS[eccFormatBits];
+#endif
+
+    struct BitBucket codewords;
+    uint8_t codewordBytes[bb_getBufferSizeBytes(moduleCount)];
+    bb_initBuffer(&codewords, codewordBytes, (int32_t)sizeof(codewordBytes));
+
+    // Place the data code words into the buffer
+    mode = encodeDataCodewords(&codewords, data, length, mode, version);
+
+    if(mode < 0) {
+        return -1;
+    }
+    qrcode->mode = mode;
+
+    // Add terminator and pad up to a byte if applicable
+    uint32_t padding = (dataCapacity * 8) - codewords.bitOffsetOrWidth;
+    if(padding > 4) {
+        padding = 4;
+    }
+    bb_appendBits(&codewords, 0, padding);
+    bb_appendBits(&codewords, 0, (8 - codewords.bitOffsetOrWidth % 8) % 8);
+
+    // Pad with alternate bytes until data capacity is reached
+    for(uint8_t padByte = 0xEC; codewords.bitOffsetOrWidth < (dataCapacity * 8);
+        padByte ^= 0xEC ^ 0x11) {
+        bb_appendBits(&codewords, padByte, 8);
+    }
+
+    BitBucket modulesGrid;
+    bb_initGrid(&modulesGrid, modules, size);
+
+    BitBucket isFunctionGrid;
+    uint8_t isFunctionGridBytes[bb_getGridSizeBytes(size)];
+    bb_initGrid(&isFunctionGrid, isFunctionGridBytes, size);
+
+    // Draw function patterns, draw all codewords, do masking
+    drawFunctionPatterns(&modulesGrid, &isFunctionGrid, version, eccFormatBits);
+    performErrorCorrection(version, eccFormatBits, &codewords);
+    drawCodewords(&modulesGrid, &isFunctionGrid, &codewords);
+
+    // Find the best (lowest penalty) mask
+    uint8_t mask = 0;
+    int32_t minPenalty = INT32_MAX;
+    for(uint8_t i = 0; i < 8; i++) {
+        drawFormatBits(&modulesGrid, &isFunctionGrid, eccFormatBits, i);
+        applyMask(&modulesGrid, &isFunctionGrid, i);
+        int penalty = getPenaltyScore(&modulesGrid);
+        if(penalty < minPenalty) {
+            mask = i;
+            minPenalty = penalty;
+        }
+        applyMask(&modulesGrid, &isFunctionGrid, i); // Undoes the mask due to XOR
+    }
+
+    qrcode->mask = mask;
+
+    // Overwrite old format bits
+    drawFormatBits(&modulesGrid, &isFunctionGrid, eccFormatBits, mask);
+
+    // Apply the final choice of mask
+    applyMask(&modulesGrid, &isFunctionGrid, mask);
+
+    return 0;
+}
+
+/* int8_t qrcode_initText(QRCode *qrcode, uint8_t *modules, uint8_t version, uint8_t ecc, const char *data) { */
+/*     return qrcode_initBytes(qrcode, modules, version, ecc, (uint8_t*)data, strlen(data)); */
+/* } */
+
+bool qrcode_getModule(QRCode* qrcode, uint8_t x, uint8_t y) {
+    if(x >= qrcode->size || y >= qrcode->size) {
+        return false;
+    }
+
+    uint32_t offset = y * qrcode->size + x;
+    return (qrcode->modules[offset >> 3] & (1 << (7 - (offset & 0x07)))) != 0;
+}
+
+/*
+uint8_t qrcode_getHexLength(QRCode *qrcode) {
+    return ((qrcode->size * qrcode->size) + 7) / 4;
+}
+
+void qrcode_getHex(QRCode *qrcode, char *result) {
+    
+}
+*/

+ 96 - 0
qrcode/qrcode.h

@@ -0,0 +1,96 @@
+/**
+ * The MIT License (MIT)
+ *
+ * This library is written and maintained by Richard Moore.
+ * Major parts were derived from Project Nayuki's library.
+ *
+ * Copyright (c) 2017 Richard Moore     (https://github.com/ricmoo/QRCode)
+ * Copyright (c) 2017 Project Nayuki    (https://www.nayuki.io/page/qr-code-generator-library)
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+
+/**
+ *  Special thanks to Nayuki (https://www.nayuki.io/) from which this library was
+ *  heavily inspired and compared against.
+ *
+ *  See: https://github.com/nayuki/QR-Code-generator/tree/master/cpp
+ */
+
+#ifndef __QRCODE_H_
+#define __QRCODE_H_
+
+// #ifndef __cplusplus
+// typedef unsigned char bool;
+// static const bool false = 0;
+// static const bool true = 1;
+// #endif
+
+#include <stdbool.h>
+#include <stdint.h>
+
+// QR Code Format Encoding
+#define MODE_NUMERIC 0
+#define MODE_ALPHANUMERIC 1
+#define MODE_BYTE 2
+
+// Error Correction Code Levels
+#define ECC_LOW 0
+#define ECC_MEDIUM 1
+#define ECC_QUARTILE 2
+#define ECC_HIGH 3
+
+// If set to non-zero, this library can ONLY produce QR codes at that version
+// This saves a lot of dynamic memory, as the codeword tables are skipped
+#ifndef LOCK_VERSION
+#define LOCK_VERSION 0
+#endif
+
+typedef struct QRCode {
+    uint8_t version;
+    uint8_t size;
+    uint8_t ecc;
+    uint8_t mode;
+    uint8_t mask;
+    uint8_t* modules;
+} QRCode;
+
+#ifdef __cplusplus
+extern "C" {
+#endif /* __cplusplus */
+
+uint16_t qrcode_getBufferSize(uint8_t version);
+
+/* int8_t qrcode_initText(QRCode *qrcode, uint8_t *modules, uint8_t version, uint8_t ecc, const char *data); */
+int8_t qrcode_initBytes(
+    QRCode* qrcode,
+    uint8_t* modules,
+    int8_t mode,
+    uint8_t version,
+    uint8_t ecc,
+    uint8_t* data,
+    uint16_t length);
+
+bool qrcode_getModule(QRCode* qrcode, uint8_t x, uint8_t y);
+
+#ifdef __cplusplus
+}
+#endif /* __cplusplus */
+
+#endif /* __QRCODE_H_ */

+ 904 - 0
qrcode/qrcode_app.c

@@ -0,0 +1,904 @@
+#include <furi.h>
+
+#include <dialogs/dialogs.h>
+#include <gui/gui.h>
+#include <storage/storage.h>
+
+#include <lib/flipper_format/flipper_format.h>
+
+// this file is generated by the build script
+#include <qrcode_icons.h>
+#include "qrcode.h"
+
+#define TAG "qrcode"
+#define QRCODE_FOLDER EXT_PATH("qrcodes")
+#define QRCODE_EXTENSION ".qrcode"
+#define QRCODE_FILETYPE "QRCode"
+#define QRCODE_FILE_VERSION 1
+
+/** Valid modes are Numeric (0), Alpha-Numeric (1), and Binary (2) */
+#define MAX_QRCODE_MODE 2
+
+/**
+ * Maximum version is 11 because the f0 screen is only 64 pixels high and
+ * version 12 is 65x65. Version 11 is 61x61.
+ */
+#define MAX_QRCODE_VERSION 11
+
+/** Valid ECC levels are Low (0), Medium (1), Quartile (2), and High (3) */
+#define MAX_QRCODE_ECC 3
+
+/** Maximum length by mode, ecc, and version */
+static const uint16_t MAX_LENGTH[3][4][MAX_QRCODE_VERSION] = {
+    {
+        // Numeric
+        {41, 77, 127, 187, 255, 322, 370, 461, 552, 652, 772}, // Low
+        {34, 63, 101, 149, 202, 255, 293, 365, 432, 513, 604}, // Medium
+        {27, 48, 77, 111, 144, 178, 207, 259, 312, 364, 427}, // Quartile
+        {17, 34, 58, 82, 106, 139, 154, 202, 235, 288, 331}, // High
+    },
+    {
+        // Alphanumeric
+        {25, 47, 77, 114, 154, 195, 224, 279, 335, 395, 468}, // Low
+        {20, 38, 61, 90, 122, 154, 178, 221, 262, 311, 366}, // Medium
+        {16, 29, 47, 67, 87, 108, 125, 157, 189, 221, 259}, // Quartile
+        {10, 20, 35, 50, 64, 84, 93, 122, 143, 174, 200}, // High
+    },
+    {
+        // Binary
+        {17, 32, 53, 78, 106, 134, 154, 192, 230, 271, 321}, // Low
+        {14, 26, 42, 62, 84, 106, 122, 152, 180, 213, 251}, // Medium
+        {11, 20, 32, 46, 60, 74, 86, 108, 130, 151, 177}, // Quartile
+        {7, 14, 24, 34, 44, 58, 64, 84, 98, 119, 137}, // High
+    },
+};
+
+/** Main app instance */
+typedef struct {
+    FuriMessageQueue* input_queue;
+    Gui* gui;
+    ViewPort* view_port;
+
+    FuriMutex** mutex;
+    FuriString* message;
+    QRCode* qrcode;
+    uint8_t min_mode;
+    uint8_t max_mode;
+    uint8_t min_version;
+    uint8_t max_ecc_at_min_version;
+    bool loading;
+    bool too_long;
+    bool show_stats;
+    uint8_t selected_idx;
+    bool edit;
+    uint8_t set_mode;
+    uint8_t set_version;
+    uint8_t set_ecc;
+} QRCodeApp;
+
+/**
+ * @param ecc ECC number
+ * @returns a character corresponding to the ecc level
+ */
+static char get_ecc_char(uint8_t ecc) {
+    switch(ecc) {
+    case 0:
+        return 'L';
+    case 1:
+        return 'M';
+    case 2:
+        return 'Q';
+    case 3:
+        return 'H';
+    default:
+        return '?';
+    }
+}
+
+/**
+ * @param ecc A character representing an ECC mode (L, M, Q, or H)
+ * @returns the ecc level or 255 representing an unknown ECC mode
+ */
+static uint8_t get_ecc_value(char ecc) {
+    switch(ecc) {
+    case 'L':
+    case 'l':
+        return 0;
+    case 'M':
+    case 'm':
+        return 1;
+    case 'Q':
+    case 'q':
+        return 2;
+    case 'H':
+    case 'h':
+        return 3;
+    default:
+        return 255;
+    }
+}
+
+/**
+ * @param mode qrcode mode
+ * @returns a character corresponding to the mode
+ */
+static char get_mode_char(uint8_t mode) {
+    switch(mode) {
+    case 0:
+        return 'N';
+    case 1:
+        return 'A';
+    case 2:
+        return 'B';
+    case 3:
+        return 'K';
+    default:
+        return '?';
+    }
+}
+
+/**
+ * @param mode A character representing a qrcode mode (N, A, or B)
+ * @returns the mode or 255 representing an unknown mode
+ */
+static uint8_t get_mode_value(char mode) {
+    switch(mode) {
+    case 'N':
+    case 'n':
+        return 0;
+    case 'A':
+    case 'a':
+        return 1;
+    case 'B':
+    case 'b':
+        return 2;
+    default:
+        return 255;
+    }
+}
+
+/**
+ * Render
+ * @param canvas The canvas to render to
+ * @param ctx Context provided to the callback by view_port_draw_callback_set
+ */
+static void render_callback(Canvas* canvas, void* ctx) {
+    furi_assert(canvas);
+    furi_assert(ctx);
+
+    QRCodeApp* instance = ctx;
+    furi_check(furi_mutex_acquire(instance->mutex, FuriWaitForever) == FuriStatusOk);
+
+    canvas_clear(canvas);
+    canvas_set_color(canvas, ColorBlack);
+    canvas_set_font(canvas, FontPrimary);
+
+    uint8_t font_height = canvas_current_font_height(canvas);
+    uint8_t width = canvas_width(canvas);
+    uint8_t height = canvas_height(canvas);
+    if(instance->loading) {
+        canvas_draw_str_aligned(
+            canvas, width / 2, height / 2, AlignCenter, AlignCenter, "Loading...");
+    } else if(instance->qrcode) {
+        uint8_t size = instance->qrcode->size;
+        uint8_t pixel_size = height / size;
+        uint8_t top = (height - pixel_size * size) / 2;
+        uint8_t left = ((instance->show_stats ? 65 : width) - pixel_size * size) / 2;
+        for(uint8_t y = 0; y < size; y++) {
+            for(uint8_t x = 0; x < size; x++) {
+                if(qrcode_getModule(instance->qrcode, x, y)) {
+                    if(pixel_size == 1) {
+                        canvas_draw_dot(canvas, left + x * pixel_size, top + y * pixel_size);
+                    } else {
+                        canvas_draw_box(
+                            canvas,
+                            left + x * pixel_size,
+                            top + y * pixel_size,
+                            pixel_size,
+                            pixel_size);
+                    }
+                }
+            }
+        }
+
+        if(instance->show_stats) {
+            top = 10;
+            left = 66;
+
+            FuriString* str = furi_string_alloc();
+
+            if(!instance->edit || instance->selected_idx == 0) {
+                furi_string_printf(str, "Mod: %c", get_mode_char(instance->set_mode));
+                canvas_draw_str(canvas, left + 5, font_height + top, furi_string_get_cstr(str));
+                if(instance->selected_idx == 0) {
+                    canvas_draw_triangle(
+                        canvas,
+                        left,
+                        top + font_height / 2,
+                        font_height - 4,
+                        4,
+                        CanvasDirectionLeftToRight);
+                }
+                if(instance->edit) {
+                    uint8_t arrow_left = left + 5 + canvas_string_width(canvas, "Mod: B") / 2;
+                    canvas_draw_triangle(
+                        canvas, arrow_left, top, font_height - 4, 4, CanvasDirectionBottomToTop);
+                    canvas_draw_triangle(
+                        canvas,
+                        arrow_left,
+                        top + font_height + 1,
+                        font_height - 4,
+                        4,
+                        CanvasDirectionTopToBottom);
+                }
+            }
+
+            if(!instance->edit || instance->selected_idx == 1) {
+                furi_string_printf(str, "Ver: %i", instance->set_version);
+                canvas_draw_str(
+                    canvas, left + 5, 2 * font_height + top + 2, furi_string_get_cstr(str));
+                if(instance->selected_idx == 1) {
+                    canvas_draw_triangle(
+                        canvas,
+                        left,
+                        3 * font_height / 2 + top + 2,
+                        font_height - 4,
+                        4,
+                        CanvasDirectionLeftToRight);
+                }
+                if(instance->edit) {
+                    uint8_t arrow_left = left + 5 + canvas_string_width(canvas, "Ver: 8") / 2;
+                    canvas_draw_triangle(
+                        canvas,
+                        arrow_left,
+                        font_height + top + 2,
+                        font_height - 4,
+                        4,
+                        CanvasDirectionBottomToTop);
+                    canvas_draw_triangle(
+                        canvas,
+                        arrow_left,
+                        2 * font_height + top + 3,
+                        font_height - 4,
+                        4,
+                        CanvasDirectionTopToBottom);
+                }
+            }
+
+            if(!instance->edit || instance->selected_idx == 2) {
+                furi_string_printf(str, "ECC: %c", get_ecc_char(instance->set_ecc));
+                canvas_draw_str(
+                    canvas, left + 5, 3 * font_height + top + 4, furi_string_get_cstr(str));
+                if(instance->selected_idx == 2) {
+                    canvas_draw_triangle(
+                        canvas,
+                        left,
+                        5 * font_height / 2 + top + 4,
+                        font_height - 4,
+                        4,
+                        CanvasDirectionLeftToRight);
+                }
+                if(instance->edit) {
+                    uint8_t arrow_left = left + 5 + canvas_string_width(canvas, "ECC: H") / 2;
+                    canvas_draw_triangle(
+                        canvas,
+                        arrow_left,
+                        2 * font_height + top + 4,
+                        font_height - 4,
+                        4,
+                        CanvasDirectionBottomToTop);
+                    canvas_draw_triangle(
+                        canvas,
+                        arrow_left,
+                        3 * font_height + top + 5,
+                        font_height - 4,
+                        4,
+                        CanvasDirectionTopToBottom);
+                }
+            }
+
+            furi_string_free(str);
+        }
+    } else {
+        uint8_t margin = (height - font_height * 2) / 3;
+        canvas_draw_str_aligned(
+            canvas, width / 2, margin, AlignCenter, AlignTop, "Could not load qrcode.");
+        if(instance->too_long) {
+            canvas_set_font(canvas, FontSecondary);
+            canvas_draw_str(canvas, width / 2, margin * 2 + font_height, "Message is too long.");
+        }
+    }
+
+    furi_mutex_release(instance->mutex);
+}
+
+/**
+ * Handle input
+ * @param input_event The received input event
+ * @param ctx Context provided to the callback by view_port_input_callback_set
+ */
+static void input_callback(InputEvent* input_event, void* ctx) {
+    furi_assert(input_event);
+    furi_assert(ctx);
+    if(input_event->type == InputTypeShort) {
+        QRCodeApp* instance = ctx;
+        furi_message_queue_put(instance->input_queue, input_event, 0);
+    }
+}
+
+/**
+ * Determine if the given string is all numeric
+ * @param str The string to test
+ * @returns true if the string is all numeric
+ */
+static bool is_numeric(const char* str, uint16_t len) {
+    furi_assert(str);
+    while(len > 0) {
+        char c = str[--len];
+        if(c < '0' || c > '9') return false;
+    }
+    return true;
+}
+
+/**
+ * Determine if the given string is alphanumeric
+ * @param str The string to test
+ * @returns true if the string is alphanumeric
+ */
+static bool is_alphanumeric(const char* str, uint16_t len) {
+    furi_assert(str);
+    while(len > 0) {
+        char c = str[--len];
+        if(c >= '0' && c <= '9') continue;
+        if(c >= 'A' && c <= 'Z') continue;
+        if(c == ' ' || c == '$' || c == '%' || c == '*' || c == '+' || c == '-' || c == '.' ||
+           c == '/' || c == ':')
+            continue;
+        return false;
+    }
+    return true;
+}
+
+/**
+ * Allocate a qrcode
+ * @param version qrcode version
+ * @returns an allocated QRCode
+ */
+static QRCode* qrcode_alloc(uint8_t version) {
+    QRCode* qrcode = malloc(sizeof(QRCode));
+    qrcode->modules = malloc(qrcode_getBufferSize(version));
+    return qrcode;
+}
+
+/**
+ * Free a QRCode
+ * @param qrcode The QRCode to free
+ */
+static void qrcode_free(QRCode* qrcode) {
+    furi_assert(qrcode);
+    free(qrcode->modules);
+    free(qrcode);
+}
+
+/**
+ * Rebuild the qrcode. Assumes that instance->message is the message to encode,
+ * that the mutex has been acquired, and the specified version/ecc will be
+ * sufficiently large enough to encode the full message. It is also assumed
+ * that the old qrcode will be free'd by the caller.
+ * @param instance The qrcode app instance
+ * @param mode The qrcode mode to use
+ * @param version The qrcode version to use
+ * @param ecc The qrcode ECC level to use
+ * @returns true if the qrcode was successfully created
+ */
+static bool rebuild_qrcode(QRCodeApp* instance, uint8_t mode, uint8_t version, uint8_t ecc) {
+    furi_assert(instance);
+    furi_assert(instance->message);
+
+    const char* cstr = furi_string_get_cstr(instance->message);
+    uint16_t len = (uint16_t)furi_string_size(instance->message);
+    instance->qrcode = qrcode_alloc(version);
+
+    int8_t res = qrcode_initBytes(
+        instance->qrcode,
+        instance->qrcode->modules,
+        (int8_t)mode,
+        version,
+        ecc,
+        (uint8_t*)cstr,
+        len);
+    if(res != 0) {
+        FURI_LOG_E(TAG, "Could not create qrcode");
+
+        qrcode_free(instance->qrcode);
+        instance->qrcode = NULL;
+
+        return false;
+    }
+    return true;
+}
+
+/**
+ * Determine the minimum version and maximum ECC for a message of a given
+ * length and mode.
+ * @param len The length of the message
+ * @param mode The mode of the encoded message
+ * @param version Pointer to variable that will receive the minimum version
+ * @param ecc Pointer to variable that will receive the maximum ECC
+ * @returns false if the data is too long for the given mode, true otherwise.
+ */
+static bool find_min_version_max_ecc(uint16_t len, uint8_t mode, uint8_t* version, uint8_t* ecc) {
+    // Figure out the smallest qrcode version that'll fit all of the data - we
+    // prefer the smallest version to maximize the pixel size of each module to
+    // improve reader performance. Here, version is the 0-based index. The
+    // qrcode_initBytes function will want a 1-based version number, so we'll
+    // add one later.
+    *ecc = ECC_LOW;
+    *version = 0;
+    while(*version < MAX_QRCODE_VERSION && MAX_LENGTH[mode][*ecc][*version] < len) {
+        (*version)++;
+    }
+
+    if(*version == MAX_QRCODE_VERSION) {
+        return false;
+    }
+
+    // Figure out the maximum ECC we can use. I shouldn't need to bounds-check
+    // ecc in this loop because I already know from the loop above that ECC_LOW
+    // (0) works... don't forget to add one to that version number, since we're
+    // using it as a 0-based number here, but qrcode_initBytes will want a
+    // 1-based number...
+    *ecc = ECC_HIGH;
+    while(MAX_LENGTH[mode][*ecc][*version] < len) {
+        (*ecc)--;
+    }
+    (*version)++;
+
+    return true;
+}
+
+/**
+ * Load a qrcode from a string
+ * @param instance The qrcode app instance
+ * @param str The message to encode as a qrcode
+ * @param desired_mode User selected mode, 255 = unset
+ * @param desired_version User selected version, 255 = unset
+ * @param desired_ecc User selected ECC, 255 = unset
+ * @returns true if the string was successfully loaded
+ */
+static bool qrcode_load_string(
+    QRCodeApp* instance,
+    FuriString* str,
+    uint8_t desired_mode,
+    uint8_t desired_version,
+    uint8_t desired_ecc) {
+    furi_assert(instance);
+    furi_assert(str);
+
+    furi_check(furi_mutex_acquire(instance->mutex, FuriWaitForever) == FuriStatusOk);
+    if(instance->message) {
+        furi_string_free(instance->message);
+        instance->message = NULL;
+    }
+    if(instance->qrcode) {
+        qrcode_free(instance->qrcode);
+        instance->qrcode = NULL;
+    }
+    instance->too_long = false;
+    instance->show_stats = false;
+    instance->selected_idx = 0;
+    instance->edit = false;
+
+    bool result = false;
+    do {
+        const char* cstr = furi_string_get_cstr(str);
+        uint16_t len = (uint16_t)furi_string_size(str);
+
+        instance->message = furi_string_alloc_set(str);
+        if(!instance->message) {
+            FURI_LOG_E(TAG, "Could not allocate message");
+            break;
+        }
+
+        // figure out the minimum qrcode "mode"
+        int8_t min_mode = MODE_BYTE;
+        if(is_numeric(cstr, len))
+            min_mode = MODE_NUMERIC;
+        else if(is_alphanumeric(cstr, len))
+            min_mode = MODE_ALPHANUMERIC;
+
+        // determine the maximum "mode"
+        int8_t max_mode = MAX_QRCODE_MODE;
+        uint8_t min_version = 0;
+        uint8_t max_ecc_at_min_version = 0;
+        while(max_mode >= min_mode &&
+              !find_min_version_max_ecc(
+                  len, (uint8_t)max_mode, &min_version, &max_ecc_at_min_version)) {
+            max_mode--;
+        }
+
+        // if the max is less than the min, the message is too long
+        if(max_mode < min_mode) {
+            instance->too_long = true;
+            break;
+        }
+
+        // pick a mode based on the min/max and desired mode
+        if(desired_mode == 255 || desired_mode < (uint8_t)min_mode) {
+            desired_mode = (uint8_t)min_mode;
+        } else if(desired_mode > (uint8_t)max_mode) {
+            desired_mode = (uint8_t)max_mode;
+        }
+        if(desired_mode != (uint8_t)max_mode) {
+            // if the desired mode equals the max mode, then min_version and
+            // max_ecc_at_min_version are already set appropriately by the max
+            // mode loop above... otherwise, we need to calculate them... this
+            // should always return true because we already know the desired
+            // mode is appropriate for the data, but, just in case...
+            if(!find_min_version_max_ecc(
+                   len, desired_mode, &min_version, &max_ecc_at_min_version)) {
+                instance->too_long = true;
+                break;
+            }
+        }
+
+        // ensure desired version and ecc are appropriate
+        if(desired_version == 255 || desired_version < min_version) {
+            desired_version = min_version;
+        } else if(desired_version > MAX_QRCODE_VERSION) {
+            desired_version = MAX_QRCODE_VERSION;
+        }
+        if(desired_version == min_version) {
+            if(desired_ecc > max_ecc_at_min_version) {
+                desired_ecc = max_ecc_at_min_version;
+            }
+        } else if(desired_ecc > MAX_QRCODE_ECC) {
+            desired_ecc = MAX_QRCODE_ECC;
+        }
+
+        // Build the qrcode
+        if(!rebuild_qrcode(instance, desired_mode, desired_version, desired_ecc)) {
+            break;
+        }
+
+        instance->min_mode = (uint8_t)min_mode;
+        instance->max_mode = (uint8_t)max_mode;
+        instance->set_mode = desired_mode;
+        instance->min_version = min_version;
+        instance->set_version = desired_version;
+        instance->max_ecc_at_min_version = max_ecc_at_min_version;
+        instance->set_ecc = desired_ecc;
+        result = true;
+    } while(false);
+
+    if(!result) {
+        if(instance->message) {
+            furi_string_free(instance->message);
+            instance->message = NULL;
+        }
+        if(instance->qrcode) {
+            qrcode_free(instance->qrcode);
+            instance->qrcode = NULL;
+        }
+    }
+
+    instance->loading = false;
+
+    furi_mutex_release(instance->mutex);
+
+    return result;
+}
+
+/**
+ * Load a qrcode from a file
+ * @param instance The qrcode app instance
+ * @param file_path Path to the file to read
+ * @returns true if the file was successfully loaded
+ */
+static bool qrcode_load_file(QRCodeApp* instance, const char* file_path) {
+    furi_assert(instance);
+    furi_assert(file_path);
+
+    FuriString* temp_str = furi_string_alloc();
+    bool result = false;
+
+    Storage* storage = furi_record_open(RECORD_STORAGE);
+    FlipperFormat* file = flipper_format_file_alloc(storage);
+
+    do {
+        if(!flipper_format_file_open_existing(file, file_path)) break;
+
+        uint32_t file_version = 0;
+        if(!flipper_format_read_header(file, temp_str, &file_version)) break;
+        if(furi_string_cmp_str(temp_str, QRCODE_FILETYPE) || file_version > QRCODE_FILE_VERSION) {
+            FURI_LOG_E(TAG, "Incorrect file format or version");
+            break;
+        }
+
+        uint32_t desired_mode = 255;
+        uint32_t desired_version = 255;
+        uint32_t desired_ecc = 255;
+        if(file_version > 0) {
+            if(flipper_format_key_exist(file, "QRMode")) {
+                if(flipper_format_read_string(file, "QRMode", temp_str)) {
+                    if(furi_string_size(temp_str) > 0) {
+                        desired_mode = get_mode_value(furi_string_get_char(temp_str, 0));
+                    }
+                } else {
+                    FURI_LOG_E(TAG, "Could not read QRMode");
+                    desired_mode = 255;
+                }
+            }
+
+            if(flipper_format_key_exist(file, "QRVersion")) {
+                if(flipper_format_read_uint32(file, "QRVersion", &desired_version, 1)) {
+                    if(desired_version > MAX_QRCODE_VERSION) {
+                        FURI_LOG_E(TAG, "Invalid QRVersion");
+                        desired_version = 255;
+                    }
+                } else {
+                    FURI_LOG_E(TAG, "Could not read QRVersion");
+                    desired_version = 255;
+                }
+            }
+
+            if(flipper_format_key_exist(file, "QRECC")) {
+                if(flipper_format_read_string(file, "QRECC", temp_str)) {
+                    if(furi_string_size(temp_str) > 0) {
+                        desired_ecc = get_ecc_value(furi_string_get_char(temp_str, 0));
+                    }
+                } else {
+                    FURI_LOG_E(TAG, "Could not read QRECC");
+                    desired_ecc = 255;
+                }
+            }
+        }
+
+        if(!flipper_format_read_string(file, "Message", temp_str)) {
+            FURI_LOG_E(TAG, "Message is missing");
+            break;
+        }
+        if(file_version > 0) {
+            FuriString* msg_cont = furi_string_alloc();
+            while(flipper_format_key_exist(file, "Message")) {
+                if(!flipper_format_read_string(file, "Message", msg_cont)) {
+                    FURI_LOG_E(TAG, "Could not read next Message");
+                    break;
+                }
+                furi_string_push_back(temp_str, '\n');
+                furi_string_cat(temp_str, msg_cont);
+            }
+            furi_string_free(msg_cont);
+        }
+
+        if(!qrcode_load_string(
+               instance,
+               temp_str,
+               (uint8_t)desired_mode,
+               (uint8_t)desired_version,
+               (uint8_t)desired_ecc)) {
+            break;
+        }
+
+        result = true;
+    } while(false);
+
+    furi_record_close(RECORD_STORAGE);
+    flipper_format_free(file);
+    furi_string_free(temp_str);
+
+    return result;
+}
+
+/**
+ * Allocate the qrcode app
+ * @returns a qrcode app instance
+ */
+static QRCodeApp* qrcode_app_alloc() {
+    QRCodeApp* instance = malloc(sizeof(QRCodeApp));
+
+    instance->input_queue = furi_message_queue_alloc(8, sizeof(InputEvent));
+
+    instance->view_port = view_port_alloc();
+    view_port_draw_callback_set(instance->view_port, render_callback, instance);
+    view_port_input_callback_set(instance->view_port, input_callback, instance);
+
+    instance->gui = furi_record_open(RECORD_GUI);
+    gui_add_view_port(instance->gui, instance->view_port, GuiLayerFullscreen);
+
+    instance->mutex = furi_mutex_alloc(FuriMutexTypeNormal);
+
+    instance->message = NULL;
+    instance->qrcode = NULL;
+    instance->loading = true;
+    instance->too_long = false;
+    instance->show_stats = false;
+    instance->selected_idx = 0;
+    instance->edit = false;
+
+    return instance;
+}
+
+/**
+ * Free the qrcode app
+ * @param qrcode_app The app to free
+ */
+static void qrcode_app_free(QRCodeApp* instance) {
+    if(instance->message) furi_string_free(instance->message);
+    if(instance->qrcode) qrcode_free(instance->qrcode);
+
+    gui_remove_view_port(instance->gui, instance->view_port);
+    furi_record_close(RECORD_GUI);
+
+    view_port_free(instance->view_port);
+
+    furi_message_queue_free(instance->input_queue);
+
+    furi_mutex_free(instance->mutex);
+
+    free(instance);
+}
+
+/** App entrypoint */
+int32_t qrcode_app(void* p) {
+    QRCodeApp* instance = qrcode_app_alloc();
+    FuriString* file_path = furi_string_alloc();
+
+    do {
+        if(p && strlen(p)) {
+            furi_string_set(file_path, (const char*)p);
+        } else {
+            furi_string_set(file_path, QRCODE_FOLDER);
+
+            DialogsFileBrowserOptions browser_options;
+            dialog_file_browser_set_basic_options(
+                &browser_options, QRCODE_EXTENSION, &I_qrcode_10px);
+            browser_options.hide_ext = true;
+            browser_options.base_path = QRCODE_FOLDER;
+
+            DialogsApp* dialogs = furi_record_open(RECORD_DIALOGS);
+            bool res = dialog_file_browser_show(dialogs, file_path, file_path, &browser_options);
+
+            furi_record_close(RECORD_DIALOGS);
+            if(!res) {
+                FURI_LOG_E(TAG, "No file selected");
+                break;
+            }
+        }
+
+        if(!qrcode_load_file(instance, furi_string_get_cstr(file_path))) {
+            FURI_LOG_E(TAG, "Unable to load file");
+        }
+
+        InputEvent input;
+        while(furi_message_queue_get(instance->input_queue, &input, FuriWaitForever) ==
+              FuriStatusOk) {
+            furi_check(furi_mutex_acquire(instance->mutex, FuriWaitForever) == FuriStatusOk);
+
+            if(input.key == InputKeyBack) {
+                if(instance->message) {
+                    furi_string_free(instance->message);
+                    instance->message = NULL;
+                }
+                if(instance->qrcode) {
+                    qrcode_free(instance->qrcode);
+                    instance->qrcode = NULL;
+                }
+                instance->loading = true;
+                instance->edit = false;
+                furi_mutex_release(instance->mutex);
+                break;
+            } else if(input.key == InputKeyRight) {
+                instance->show_stats = true;
+            } else if(input.key == InputKeyLeft) {
+                instance->show_stats = false;
+            } else if(instance->show_stats && !instance->loading && instance->qrcode) {
+                if(input.key == InputKeyUp) {
+                    if(!instance->edit) {
+                        instance->selected_idx = MAX(0, instance->selected_idx - 1);
+                    } else {
+                        if(instance->selected_idx == 0 &&
+                           instance->set_mode < instance->max_mode) {
+                            instance->set_mode++;
+                        } else if(
+                            instance->selected_idx == 1 &&
+                            instance->set_version < MAX_QRCODE_VERSION) {
+                            instance->set_version++;
+                        } else if(instance->selected_idx == 2) {
+                            uint8_t max_ecc = instance->set_version == instance->min_version ?
+                                                  instance->max_ecc_at_min_version :
+                                                  ECC_HIGH;
+                            if(instance->set_ecc < max_ecc) {
+                                instance->set_ecc++;
+                            }
+                        }
+                    }
+                } else if(input.key == InputKeyDown) {
+                    if(!instance->edit) {
+                        instance->selected_idx = MIN(2, instance->selected_idx + 1);
+                    } else {
+                        if(instance->selected_idx == 0 &&
+                           instance->set_mode > instance->min_mode) {
+                            instance->set_mode--;
+                        } else if(
+                            instance->selected_idx == 1 &&
+                            instance->set_version > instance->min_version) {
+                            instance->set_version--;
+                            if(instance->set_version == instance->min_version) {
+                                instance->set_ecc =
+                                    MIN(instance->set_ecc, instance->max_ecc_at_min_version);
+                            }
+                        } else if(instance->selected_idx == 2 && instance->set_ecc > 0) {
+                            instance->set_ecc--;
+                        }
+                    }
+                } else if(input.key == InputKeyOk) {
+                    if(instance->edit && (instance->set_mode != instance->qrcode->mode ||
+                                          instance->set_version != instance->qrcode->version ||
+                                          instance->set_ecc != instance->qrcode->ecc)) {
+                        uint8_t orig_min_version = instance->min_version;
+                        uint8_t orig_max_ecc_at_min_version = instance->max_ecc_at_min_version;
+                        if(instance->set_mode != instance->qrcode->mode) {
+                            uint16_t len = (uint16_t)furi_string_size(instance->message);
+                            uint8_t min_version = 0;
+                            uint8_t max_ecc_at_min_version = 0;
+                            if(find_min_version_max_ecc(
+                                   len,
+                                   instance->set_mode,
+                                   &min_version,
+                                   &max_ecc_at_min_version)) {
+                                if(instance->set_version < min_version) {
+                                    instance->set_version = min_version;
+                                }
+                                if(instance->set_version == min_version &&
+                                   instance->set_ecc > max_ecc_at_min_version) {
+                                    instance->set_ecc = max_ecc_at_min_version;
+                                }
+                                instance->min_version = min_version;
+                                instance->max_ecc_at_min_version = max_ecc_at_min_version;
+                            } else {
+                                instance->set_mode = instance->qrcode->mode;
+                            }
+                        }
+
+                        QRCode* qrcode = instance->qrcode;
+                        instance->loading = true;
+
+                        if(rebuild_qrcode(
+                               instance,
+                               instance->set_mode,
+                               instance->set_version,
+                               instance->set_ecc)) {
+                            qrcode_free(qrcode);
+                        } else {
+                            FURI_LOG_E(TAG, "Could not rebuild qrcode");
+                            instance->qrcode = qrcode;
+                            instance->set_mode = qrcode->mode;
+                            instance->set_version = qrcode->version;
+                            instance->set_ecc = qrcode->ecc;
+                            instance->min_version = orig_min_version;
+                            instance->max_ecc_at_min_version = orig_max_ecc_at_min_version;
+                        }
+
+                        instance->loading = false;
+                    }
+                    instance->edit = !instance->edit;
+                }
+            }
+
+            furi_mutex_release(instance->mutex);
+            view_port_update(instance->view_port);
+        }
+
+        if(p && strlen(p)) {
+            // if started with an arg, exit instead
+            // of looping back to the browser
+            break;
+        }
+    } while(true);
+
+    furi_string_free(file_path);
+    qrcode_app_free(instance);
+
+    return 0;
+}

+ 26 - 0
qrcode/scripts/check-firmware.sh

@@ -0,0 +1,26 @@
+#!/bin/bash
+set -Exeuo pipefail
+
+print_status() {
+  local level="$1"
+  local body="${2//%/%25}"
+  body="${body//$'\r'/}"
+  body="${body//$'\n'/%0A}"
+
+  echo "::$level::$body"
+}
+
+SCRIPT_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")"; pwd -P)"
+FIRMWARE_DIR="$1"
+
+LASTVER="$(git -C "$SCRIPT_DIR" tag | grep firmware-v | sort -V | tail -n1 | sed -e 's/^firmware-v//')"
+print_status notice "last built against firmware version: $LASTVER"
+
+VER="$(git -C "$FIRMWARE_DIR" tag | sed -E -e '/^[0-9]+\.[0-9]+\.[0-9]+$/!d' | sort -V | sed -e "1,/$LASTVER/d" | tail -n1)"
+# VER="$(curl https://api.github.com/repos/flipperdevices/flipperzero-firmware/tags | jq -r --arg current "$LASTVER" 'def ver($v): $v | ltrimstr("v") | split(".") | map(tonumber); map(.name) | map(select(. | test("^\\d+\\.\\d+\\.\\d+$";"s"))) | map(ver(.)) | map(select(. > ver($current))) | sort | last | if . == null then "" else join(".") end')"
+if [ -z "$VER" ]; then
+  print_status notice "no new firmware version"
+  exit 0
+fi
+print_status notice "new firmware version: $VER"
+echo "version=$VER" >> $GITHUB_OUTPUT

+ 43 - 0
qrcode/scripts/update-firmware.sh

@@ -0,0 +1,43 @@
+#!/bin/bash
+set -Exeuo pipefail
+
+print_status() {
+  local level="$1"
+  local body="${2//%/%25}"
+  body="${body//$'\r'/}"
+  body="${body//$'\n'/%0A}"
+
+  echo "::$level::$body"
+}
+
+SCRIPT_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")"; pwd -P)"
+FIRMWARE_VER="$1"
+
+pushd "$(git -C "$SCRIPT_DIR" rev-parse --show-toplevel)"
+print_status notice "updating to firmware $FIRMWARE_VER"
+
+# setup git
+git config --local user.name $GIT_USER_NAME
+git config --local user.email $GIT_USER_EMAIL
+
+# construct a new version number for the qrcode app
+VER="$(git tag | sed -E -e '/^v[0-9]+\.[0-9]+\.[0-9]+$/!d' | sort -V | tail -n1)"
+if [[ "$VER" =~ ^(v[0-9]+.[0-9]+).([0-9]+)$ ]]; then
+    VER="${BASH_REMATCH[1]}.$(( ${BASH_REMATCH[2]} + 1 ))"
+else
+    print_status warning "couldn't construct new version number from $VER"
+    exit 1
+fi
+print_status notice "new qrcode version: $VER"
+
+# update firmware version in automation
+sed -i -e "/firmware_version:/s/'.*'/'$FIRMWARE_VER'/" .github/workflows/release.yml
+
+# commit and tag
+git add .github/workflows/release.yml
+git commit -m "update to firmware $FIRMWARE_VER"
+git tag -a -m "$VER" "$VER"
+git tag "firmware-v$FIRMWARE_VER"
+git push --atomic origin main "$VER" "firmware-v$FIRMWARE_VER"
+
+popd