Add lightmeter from https://github.com/oleksiikutuzov/flipperzero-lightmeter

git-subtree-dir: lightmeter
git-subtree-mainline: a2005d3c1017a55b37c3d49ad983e37486e8a801
git-subtree-split: 8a1ccc47e730f1b34c58931ec642d59562d020ba

lightmeter/.clang-format

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lightmeter/.gitignore

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+dist/*
+.vscode
+.clang-format
+.editorconfig

lightmeter/.gitsubtree

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+https://github.com/oleksiikutuzov/flipperzero-lightmeter main application

lightmeter/application.fam

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+App(
+    appid="lightmeter",
+    name="Lightmeter",
+    apptype=FlipperAppType.EXTERNAL,
+    entry_point="lightmeter_app",
+    cdefines=["APP_LIGHTMETER"],
+    requires=[
+        "gui",
+    ],
+    stack_size= 4 * 1024,
+    order=90,
+    fap_version=(1, 2),
+    fap_icon="lightmeter.png",
+    fap_category="GPIO",
+    fap_private_libs=[
+        Lib(
+            name="BH1750",
+            cincludes=["."],
+            sources=[
+                "BH1750.c",
+            ],
+        ),
+        Lib(
+            name="MAX44009",
+            cincludes=["."],
+            sources=[
+                "MAX44009.c",
+            ],
+        ),
+    ],
+    fap_description="Lightmeter app for photography",
+    fap_author="Oleksii Kutuzov",
+    fap_weburl="https://github.com/oleksiikutuzov/flipperzero-lightmeter",
+    fap_icon_assets="icons",
+)

lightmeter/docs/README.md

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+## Lightmeter app for photography
+
+An application that suggests settings for your manual camera based on the reading of the ambient light sensor. Can also be used in a pure lux meter mode.
+
+## Supported sensors
+
+- BH1750
+- MAX44009
+
+## Wiring
+
+| Sensor | Flipper Zero |
+| ------ | ------------ |
+| VCC    | 3.3V         |
+| GND    | GND          |
+| SCL    | C0           |
+| SDA    | C1           |

lightmeter/docs/changelog.md

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+## v1.2
+
+* Lux only screen now has statistics
+* Settings are now stored on SD card
+* You can choose the resolution (BH1750 only) and address for sensor
+
+(thanks to @danielskowronski for contributing to this update)
+
+## v1.1
+
+Added support for MAX44009 sensor (thanks to @wosk)
+
+## v1.0
+
+Initial release for Flipper Application Catalog

lightmeter/gui/scenes/config/lightmeter_scene.c

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+#include "lightmeter_scene.h"
+
+// Generate scene on_enter handlers array
+#define ADD_SCENE(prefix, name, id) prefix##_scene_##name##_on_enter,
+void (*const lightmeter_on_enter_handlers[])(void*) = {
+#include "lightmeter_scene_config.h"
+};
+#undef ADD_SCENE
+
+// Generate scene on_event handlers array
+#define ADD_SCENE(prefix, name, id) prefix##_scene_##name##_on_event,
+bool (*const lightmeter_on_event_handlers[])(void* context, SceneManagerEvent event) = {
+#include "lightmeter_scene_config.h"
+};
+#undef ADD_SCENE
+
+// Generate scene on_exit handlers array
+#define ADD_SCENE(prefix, name, id) prefix##_scene_##name##_on_exit,
+void (*const lightmeter_on_exit_handlers[])(void* context) = {
+#include "lightmeter_scene_config.h"
+};
+#undef ADD_SCENE
+
+// Initialize scene handlers configuration structure
+const SceneManagerHandlers lightmeter_scene_handlers = {
+    .on_enter_handlers = lightmeter_on_enter_handlers,
+    .on_event_handlers = lightmeter_on_event_handlers,
+    .on_exit_handlers = lightmeter_on_exit_handlers,
+    .scene_num = LightMeterAppSceneNum,
+};

lightmeter/gui/scenes/config/lightmeter_scene.h

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+#pragma once
+
+#include <gui/scene_manager.h>
+
+// Generate scene id and total number
+#define ADD_SCENE(prefix, name, id) LightMeterAppScene##id,
+typedef enum {
+#include "lightmeter_scene_config.h"
+    LightMeterAppSceneNum,
+} LightMeterAppScene;
+#undef ADD_SCENE
+
+extern const SceneManagerHandlers lightmeter_scene_handlers;
+
+// Generate scene on_enter handlers declaration
+#define ADD_SCENE(prefix, name, id) void prefix##_scene_##name##_on_enter(void*);
+#include "lightmeter_scene_config.h"
+#undef ADD_SCENE
+
+// Generate scene on_event handlers declaration
+#define ADD_SCENE(prefix, name, id) \
+    bool prefix##_scene_##name##_on_event(void* context, SceneManagerEvent event);
+#include "lightmeter_scene_config.h"
+#undef ADD_SCENE
+
+// Generate scene on_exit handlers declaration
+#define ADD_SCENE(prefix, name, id) void prefix##_scene_##name##_on_exit(void* context);
+#include "lightmeter_scene_config.h"
+#undef ADD_SCENE

lightmeter/gui/scenes/config/lightmeter_scene_config.h

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+ADD_SCENE(lightmeter, main, Main)
+ADD_SCENE(lightmeter, config, Config)
+ADD_SCENE(lightmeter, help, Help)
+ADD_SCENE(lightmeter, about, About)

lightmeter/gui/scenes/lightmeter_scene_about.c

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+#include "../../lightmeter.h"
+
+void lightmeter_scene_about_widget_callback(GuiButtonType result, InputType type, void* context) {
+    LightMeterApp* app = context;
+
+    UNUSED(app);
+    UNUSED(result);
+    UNUSED(type);
+    if(type == InputTypeShort) {
+        view_dispatcher_send_custom_event(app->view_dispatcher, result);
+    }
+}
+
+void lightmeter_scene_about_on_enter(void* context) {
+    LightMeterApp* app = context;
+
+    FuriString* temp_str;
+    temp_str = furi_string_alloc();
+    furi_string_printf(temp_str, "\e#%s\n", "Information");
+
+    furi_string_cat_printf(temp_str, "Version: %s\n", LM_VERSION_APP);
+    furi_string_cat_printf(temp_str, "Developed by: %s\n", LM_DEVELOPED);
+    furi_string_cat_printf(temp_str, "Github: %s\n\n", LM_GITHUB);
+
+    furi_string_cat_printf(temp_str, "\e#%s\n", "Description");
+    furi_string_cat_printf(
+        temp_str,
+        "Showing suggested camera\nsettings based on ambient\nlight or flash.\n\nInspired by a lightmeter\nproject by vpominchuk\n");
+
+    widget_add_text_box_element(
+        app->widget,
+        0,
+        0,
+        128,
+        14,
+        AlignCenter,
+        AlignBottom,
+        "\e#\e!                                                      \e!\n",
+        false);
+    widget_add_text_box_element(
+        app->widget,
+        0,
+        2,
+        128,
+        14,
+        AlignCenter,
+        AlignBottom,
+        "\e#\e!            Lightmeter            \e!\n",
+        false);
+    widget_add_text_scroll_element(app->widget, 0, 16, 128, 50, furi_string_get_cstr(temp_str));
+    furi_string_free(temp_str);
+
+    view_dispatcher_switch_to_view(app->view_dispatcher, LightMeterAppViewAbout);
+}
+
+bool lightmeter_scene_about_on_event(void* context, SceneManagerEvent event) {
+    LightMeterApp* app = context;
+
+    bool consumed = false;
+    UNUSED(app);
+    UNUSED(event);
+
+    return consumed;
+}
+
+void lightmeter_scene_about_on_exit(void* context) {
+    LightMeterApp* app = context;
+
+    // Clear views
+    widget_reset(app->widget);
+}

lightmeter/gui/scenes/lightmeter_scene_config.c

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+#include "../../lightmeter.h"
+
+#define TAG "Scene Config"
+
+static const char* iso_numbers[] = {
+    [ISO_6] = "6",
+    [ISO_12] = "12",
+    [ISO_25] = "25",
+    [ISO_50] = "50",
+    [ISO_100] = "100",
+    [ISO_200] = "200",
+    [ISO_400] = "400",
+    [ISO_800] = "800",
+    [ISO_1600] = "1600",
+    [ISO_3200] = "3200",
+    [ISO_6400] = "6400",
+    [ISO_12800] = "12800",
+    [ISO_25600] = "25600",
+    [ISO_51200] = "51200",
+    [ISO_102400] = "102400",
+};
+
+static const char* nd_numbers[] = {
+    [ND_0] = "0",
+    [ND_2] = "2",
+    [ND_4] = "4",
+    [ND_8] = "8",
+    [ND_16] = "16",
+    [ND_32] = "32",
+    [ND_64] = "64",
+    [ND_128] = "128",
+    [ND_256] = "256",
+    [ND_512] = "512",
+    [ND_1024] = "1024",
+    [ND_2048] = "2048",
+    [ND_4096] = "4096",
+};
+
+static const char* diffusion_dome[] = {
+    [WITHOUT_DOME] = "No",
+    [WITH_DOME] = "Yes",
+};
+
+static const char* backlight[] = {
+    [BACKLIGHT_AUTO] = "Auto",
+    [BACKLIGHT_ON] = "On",
+};
+
+static const char* lux_only[] = {
+    [LUX_ONLY_OFF] = "Off",
+    [LUX_ONLY_ON] = "On",
+};
+
+static const char* sensor_type[] = {
+    [SENSOR_BH1750] = "BH1750",
+    [SENSOR_MAX44009] = "MAX44009",
+};
+
+static const char* measurement_resolution[] = {
+    [LOW_RES] = "Low",
+    [HIGH_RES] = "High",
+    [HIGH_RES2] = "High2",
+};
+
+static const char* device_addr_bh1750[] = {
+    [ADDR_LOW] = "0x23",
+    [ADDR_HIGH] = "0x5C",
+};
+
+static const char* device_addr_max44009[] = {
+    [ADDR_LOW] = "0x4A",
+    [ADDR_HIGH] = "0x4B",
+};
+
+enum LightMeterSubmenuIndex {
+    LightMeterSubmenuIndexISO,
+    LightMeterSubmenuIndexND,
+    LightMeterSubmenuIndexDome,
+    LightMeterSubmenuIndexBacklight,
+    LightMeterSubmenuIndexLuxMeter,
+    LightMeterSubmenuIndexSensorType,
+    LightMeterSubmenuIndexMeasurementResolution,
+    LightMeterSubmenuIndexI2CAddress,
+    LightMeterSubmenuIndexHelp,
+    LightMeterSubmenuIndexAbout,
+};
+
+static void iso_numbers_cb(VariableItem* item) {
+    LightMeterApp* app = variable_item_get_context(item);
+    uint8_t index = variable_item_get_current_value_index(item);
+
+    variable_item_set_current_value_text(item, iso_numbers[index]);
+
+    LightMeterConfig* config = app->config;
+    config->iso = index;
+    lightmeter_app_set_config(app, config);
+}
+
+static void nd_numbers_cb(VariableItem* item) {
+    LightMeterApp* app = variable_item_get_context(item);
+    uint8_t index = variable_item_get_current_value_index(item);
+
+    variable_item_set_current_value_text(item, nd_numbers[index]);
+
+    LightMeterConfig* config = app->config;
+    config->nd = index;
+    lightmeter_app_set_config(app, config);
+}
+
+static void dome_presence_cb(VariableItem* item) {
+    LightMeterApp* app = variable_item_get_context(item);
+    uint8_t index = variable_item_get_current_value_index(item);
+
+    variable_item_set_current_value_text(item, diffusion_dome[index]);
+
+    LightMeterConfig* config = app->config;
+    config->dome = index;
+    lightmeter_app_set_config(app, config);
+}
+
+static void backlight_cb(VariableItem* item) {
+    LightMeterApp* app = variable_item_get_context(item);
+    uint8_t index = variable_item_get_current_value_index(item);
+
+    variable_item_set_current_value_text(item, backlight[index]);
+
+    LightMeterConfig* config = app->config;
+    if(index != config->backlight) {
+        if(index == BACKLIGHT_ON) {
+            notification_message(
+                app->notifications,
+                &sequence_display_backlight_enforce_on); // force on backlight
+        } else {
+            notification_message(
+                app->notifications,
+                &sequence_display_backlight_enforce_auto); // force auto backlight
+        }
+    }
+    config->backlight = index;
+    lightmeter_app_set_config(app, config);
+}
+
+static void lux_only_cb(VariableItem* item) {
+    LightMeterApp* app = variable_item_get_context(item);
+    uint8_t index = variable_item_get_current_value_index(item);
+
+    variable_item_set_current_value_text(item, lux_only[index]);
+
+    LightMeterConfig* config = app->config;
+    config->lux_only = index;
+    lightmeter_app_set_config(app, config);
+}
+
+static void measurement_resolution_cb(VariableItem* item) {
+    LightMeterApp* app = variable_item_get_context(item);
+    uint8_t index = variable_item_get_current_value_index(item);
+
+    variable_item_set_current_value_text(item, measurement_resolution[index]);
+
+    LightMeterConfig* config = app->config;
+    config->measurement_resolution = index;
+    lightmeter_app_set_config(app, config);
+
+    lightmeter_app_i2c_init_sensor(app);
+}
+
+static void update_item_addr(LightMeterApp* app) {
+    VariableItem* item = app->var_item_addr;
+    switch(app->config->sensor_type) {
+    case SENSOR_BH1750:
+        variable_item_set_current_value_index(item, app->config->device_addr);
+        variable_item_set_current_value_text(item, device_addr_bh1750[app->config->device_addr]);
+        break;
+    case SENSOR_MAX44009:
+        variable_item_set_current_value_index(item, app->config->device_addr);
+        variable_item_set_current_value_text(item, device_addr_max44009[app->config->device_addr]);
+        break;
+    default:
+        FURI_LOG_E(TAG, "Invalid sensor type %ld", app->config->sensor_type);
+        return;
+    }
+}
+
+static void device_addr_cb(VariableItem* item) {
+    LightMeterApp* app = variable_item_get_context(item);
+    uint8_t index = variable_item_get_current_value_index(item);
+
+    switch(app->config->sensor_type) {
+    case SENSOR_BH1750:
+        variable_item_set_current_value_text(item, device_addr_bh1750[index]);
+        break;
+    case SENSOR_MAX44009:
+        variable_item_set_current_value_text(item, device_addr_max44009[index]);
+        break;
+    default:
+        FURI_LOG_E(TAG, "Invalid sensor type %ld", app->config->sensor_type);
+        return;
+    }
+    // variable_item_set_current_value_text(item, device_addr[index]);
+
+    LightMeterConfig* config = app->config;
+    config->device_addr = index;
+    lightmeter_app_set_config(app, config);
+
+    lightmeter_app_i2c_init_sensor(app);
+}
+
+static void sensor_type_cb(VariableItem* item) {
+    LightMeterApp* app = variable_item_get_context(item);
+    uint8_t index = variable_item_get_current_value_index(item);
+
+    variable_item_set_current_value_text(item, sensor_type[index]);
+
+    LightMeterConfig* config = app->config;
+    config->sensor_type = index;
+
+    update_item_addr(app);
+
+    lightmeter_app_set_config(app, config);
+}
+
+static void ok_cb(void* context, uint32_t index) {
+    LightMeterApp* app = context;
+    UNUSED(app);
+    switch(index) {
+    case LightMeterSubmenuIndexHelp:
+        view_dispatcher_send_custom_event(app->view_dispatcher, LightMeterAppCustomEventHelp);
+        break;
+    case LightMeterSubmenuIndexAbout:
+        view_dispatcher_send_custom_event(app->view_dispatcher, LightMeterAppCustomEventAbout);
+        break;
+    default:
+        break;
+    }
+}
+
+void lightmeter_scene_config_on_enter(void* context) {
+    LightMeterApp* app = context;
+    VariableItemList* var_item_list = app->var_item_list;
+    VariableItem* item;
+    LightMeterConfig* config = app->config;
+
+    item =
+        variable_item_list_add(var_item_list, "ISO", COUNT_OF(iso_numbers), iso_numbers_cb, app);
+    variable_item_set_current_value_index(item, config->iso);
+    variable_item_set_current_value_text(item, iso_numbers[config->iso]);
+
+    item = variable_item_list_add(
+        var_item_list, "ND factor", COUNT_OF(nd_numbers), nd_numbers_cb, app);
+    variable_item_set_current_value_index(item, config->nd);
+    variable_item_set_current_value_text(item, nd_numbers[config->nd]);
+
+    item = variable_item_list_add(
+        var_item_list, "Diffusion dome", COUNT_OF(diffusion_dome), dome_presence_cb, app);
+    variable_item_set_current_value_index(item, config->dome);
+    variable_item_set_current_value_text(item, diffusion_dome[config->dome]);
+
+    item =
+        variable_item_list_add(var_item_list, "Backlight", COUNT_OF(backlight), backlight_cb, app);
+    variable_item_set_current_value_index(item, config->backlight);
+    variable_item_set_current_value_text(item, backlight[config->backlight]);
+
+    item = variable_item_list_add(
+        var_item_list, "Lux meter only", COUNT_OF(lux_only), lux_only_cb, app);
+    variable_item_set_current_value_index(item, config->lux_only);
+    variable_item_set_current_value_text(item, lux_only[config->lux_only]);
+
+    item = variable_item_list_add(
+        var_item_list, "Sensor", COUNT_OF(sensor_type), sensor_type_cb, app);
+    variable_item_set_current_value_index(item, config->sensor_type);
+    variable_item_set_current_value_text(item, sensor_type[config->sensor_type]);
+
+    item = variable_item_list_add(
+        var_item_list,
+        "Resolution",
+        COUNT_OF(measurement_resolution),
+        measurement_resolution_cb,
+        app);
+    variable_item_set_current_value_index(item, config->measurement_resolution);
+    variable_item_set_current_value_text(
+        item, measurement_resolution[config->measurement_resolution]);
+
+    switch(config->sensor_type) {
+    case SENSOR_BH1750:
+        item = variable_item_list_add(
+            var_item_list, "I2C address", COUNT_OF(device_addr_bh1750), device_addr_cb, app);
+        variable_item_set_current_value_index(item, config->device_addr);
+        variable_item_set_current_value_text(item, device_addr_bh1750[config->device_addr]);
+        break;
+    case SENSOR_MAX44009:
+        item = variable_item_list_add(
+            var_item_list, "I2C address", COUNT_OF(device_addr_max44009), device_addr_cb, app);
+        variable_item_set_current_value_index(item, config->device_addr);
+        variable_item_set_current_value_text(item, device_addr_max44009[config->device_addr]);
+        break;
+    default:
+        FURI_LOG_E(TAG, "Invalid sensor type %ld", config->sensor_type);
+        return;
+    }
+    app->var_item_addr = item;
+    update_item_addr(app);
+
+    item = variable_item_list_add(var_item_list, "Help and Pinout", 0, NULL, NULL);
+    item = variable_item_list_add(var_item_list, "About", 0, NULL, NULL);
+
+    variable_item_list_set_selected_item(
+        var_item_list,
+        scene_manager_get_scene_state(app->scene_manager, LightMeterAppSceneConfig));
+
+    variable_item_list_set_enter_callback(var_item_list, ok_cb, app);
+
+    view_dispatcher_switch_to_view(app->view_dispatcher, LightMeterAppViewVarItemList);
+}
+
+bool lightmeter_scene_config_on_event(void* context, SceneManagerEvent event) {
+    LightMeterApp* app = context;
+    bool consumed = false;
+
+    if(event.type == SceneManagerEventTypeTick) {
+        consumed = true;
+    } else if(event.type == SceneManagerEventTypeCustom) {
+        switch(event.event) {
+        case LightMeterAppCustomEventHelp:
+            scene_manager_next_scene(app->scene_manager, LightMeterAppSceneHelp);
+            consumed = true;
+            break;
+        case LightMeterAppCustomEventAbout:
+            scene_manager_next_scene(app->scene_manager, LightMeterAppSceneAbout);
+            consumed = true;
+            break;
+        }
+    }
+    return consumed;
+}
+
+void lightmeter_scene_config_on_exit(void* context) {
+    LightMeterApp* app = context;
+    variable_item_list_reset(app->var_item_list);
+    main_view_set_iso(app->main_view, app->config->iso);
+    main_view_set_nd(app->main_view, app->config->nd);
+    main_view_set_dome(app->main_view, app->config->dome);
+    main_view_set_lux_only(app->main_view, app->config->lux_only);
+    main_view_set_measurement_resolution(app->main_view, app->config->measurement_resolution);
+}

lightmeter/gui/scenes/lightmeter_scene_help.c

@@ -0,0 +1,41 @@
+#include "../../lightmeter.h"
+
+void lightmeter_scene_help_on_enter(void* context) {
+    LightMeterApp* app = context;
+
+    FuriString* temp_str;
+    temp_str = furi_string_alloc();
+    furi_string_printf(
+        temp_str,
+        "App works with BH1750/MAX44009\nambient light sensor\nconnected via I2C interface\n\n");
+    furi_string_cat(temp_str, "\e#Pinout:\r\n");
+    furi_string_cat(
+        temp_str,
+        "    VCC: 3.3V\r\n"
+        "    GND: GND\r\n"
+        "    SDA: 15 [C1]\r\n"
+        "    SCL: 16 [C0]\r\n");
+    furi_string_cat(temp_str, "\r\n\e#Resolutions:\r\n");
+    furi_string_cat(
+        temp_str,
+        "Low: 4.0lx (16ms, 0-54k)\r\n"
+        "High: 1.0lx (120ms, 0-54k)\r\n"
+        "High2: 0.5lx (120ms, 0-27k)\r\n");
+
+    widget_add_text_scroll_element(app->widget, 0, 0, 128, 64, furi_string_get_cstr(temp_str));
+    furi_string_free(temp_str);
+
+    view_dispatcher_switch_to_view(app->view_dispatcher, LightMeterAppViewHelp);
+}
+
+bool lightmeter_scene_help_on_event(void* context, SceneManagerEvent event) {
+    UNUSED(context);
+    UNUSED(event);
+    return false;
+}
+
+void lightmeter_scene_help_on_exit(void* context) {
+    LightMeterApp* app = context;
+
+    widget_reset(app->widget);
+}

lightmeter/gui/scenes/lightmeter_scene_main.c

@@ -0,0 +1,60 @@
+#include "../../lightmeter.h"
+
+static void lightmeter_scene_main_on_left(void* context) {
+    LightMeterApp* app = context;
+
+    view_dispatcher_send_custom_event(app->view_dispatcher, LightMeterAppCustomEventConfig);
+}
+
+static void lightmeter_scene_main_on_right(void* context) {
+    LightMeterApp* app = context;
+
+    view_dispatcher_send_custom_event(app->view_dispatcher, LightMeterAppCustomEventReset);
+}
+
+void lightmeter_scene_main_on_enter(void* context) {
+    LightMeterApp* app = context;
+
+    variable_item_list_reset(app->var_item_list);
+    main_view_set_iso(app->main_view, app->config->iso);
+    main_view_set_nd(app->main_view, app->config->nd);
+    main_view_set_dome(app->main_view, app->config->dome);
+    main_view_set_lux_only(app->main_view, app->config->lux_only);
+    main_view_set_measurement_resolution(app->main_view, app->config->measurement_resolution);
+
+    lightmeter_main_view_set_left_callback(app->main_view, lightmeter_scene_main_on_left, app);
+    lightmeter_main_view_set_right_callback(app->main_view, lightmeter_scene_main_on_right, app);
+    view_dispatcher_switch_to_view(app->view_dispatcher, LightMeterAppViewMainView);
+}
+
+bool lightmeter_scene_main_on_event(void* context, SceneManagerEvent event) {
+    LightMeterApp* app = context;
+
+    bool response = false;
+
+    switch(event.type) {
+    case SceneManagerEventTypeCustom:
+        if(event.event == LightMeterAppCustomEventConfig) {
+            scene_manager_next_scene(app->scene_manager, LightMeterAppSceneConfig);
+            response = true;
+        } else if(event.event == LightMeterAppCustomEventReset) {
+            lightmeter_app_reset_callback(app);
+            response = true;
+        }
+        break;
+
+    case SceneManagerEventTypeTick:
+        lightmeter_app_i2c_callback(app);
+        response = true;
+        break;
+
+    default:
+        break;
+    }
+
+    return response;
+}
+
+void lightmeter_scene_main_on_exit(void* context) {
+    UNUSED(context);
+}

lightmeter/gui/views/main_view.c

@@ -0,0 +1,548 @@
+#include "main_view.h"
+#include <math.h>
+#include <furi.h>
+#include <furi_hal.h>
+#include <gui/elements.h>
+#include "../../lightmeter.h"
+#include "../../lightmeter_helper.h"
+
+#define WORKER_TAG "Main View"
+
+static const int iso_numbers[] = {
+    [ISO_6] = 6,
+    [ISO_12] = 12,
+    [ISO_25] = 25,
+    [ISO_50] = 50,
+    [ISO_100] = 100,
+    [ISO_200] = 200,
+    [ISO_400] = 400,
+    [ISO_800] = 800,
+    [ISO_1600] = 1600,
+    [ISO_3200] = 3200,
+    [ISO_6400] = 6400,
+    [ISO_12800] = 12800,
+    [ISO_25600] = 25600,
+    [ISO_51200] = 51200,
+    [ISO_102400] = 102400,
+};
+
+static const int nd_numbers[] = {
+    [ND_0] = 0,
+    [ND_2] = 2,
+    [ND_4] = 4,
+    [ND_8] = 8,
+    [ND_16] = 16,
+    [ND_32] = 32,
+    [ND_64] = 64,
+    [ND_128] = 128,
+    [ND_256] = 256,
+    [ND_512] = 512,
+    [ND_1024] = 1024,
+    [ND_2048] = 2048,
+    [ND_4096] = 4096,
+};
+
+const float aperture_numbers[] = {
+    [AP_1] = 1.0,
+    [AP_1_4] = 1.4,
+    [AP_2] = 2.0,
+    [AP_2_8] = 2.8,
+    [AP_4] = 4.0,
+    [AP_5_6] = 5.6,
+    [AP_8] = 8,
+    [AP_11] = 11,
+    [AP_16] = 16,
+    [AP_22] = 22,
+    [AP_32] = 32,
+    [AP_45] = 45,
+    [AP_64] = 64,
+    [AP_90] = 90,
+    [AP_128] = 128,
+};
+
+const float speed_numbers[] = {
+    [SPEED_8000] = 1.0 / 8000, [SPEED_4000] = 1.0 / 4000, [SPEED_2000] = 1.0 / 2000,
+    [SPEED_1000] = 1.0 / 1000, [SPEED_500] = 1.0 / 500,   [SPEED_250] = 1.0 / 250,
+    [SPEED_125] = 1.0 / 125,   [SPEED_60] = 1.0 / 60,     [SPEED_48] = 1.0 / 48,
+    [SPEED_30] = 1.0 / 30,     [SPEED_15] = 1.0 / 15,     [SPEED_8] = 1.0 / 8,
+    [SPEED_4] = 1.0 / 4,       [SPEED_2] = 1.0 / 2,       [SPEED_1S] = 1.0,
+    [SPEED_2S] = 2.0,          [SPEED_4S] = 4.0,          [SPEED_8S] = 8.0,
+    [SPEED_15S] = 15.0,        [SPEED_30S] = 30.0,
+};
+
+struct MainView {
+    View* view;
+    LightMeterMainViewButtonCallback cb_left;
+    LightMeterMainViewButtonCallback cb_right;
+    void* cb_context;
+};
+
+void lightmeter_main_view_set_left_callback(
+    MainView* lightmeter_main_view,
+    LightMeterMainViewButtonCallback callback,
+    void* context) {
+    with_view_model(
+        lightmeter_main_view->view,
+        MainViewModel * model,
+        {
+            UNUSED(model);
+            lightmeter_main_view->cb_left = callback;
+            lightmeter_main_view->cb_context = context;
+        },
+        true);
+}
+
+void lightmeter_main_view_set_right_callback(
+    MainView* lightmeter_main_view,
+    LightMeterMainViewButtonCallback callback,
+    void* context) {
+    with_view_model(
+        lightmeter_main_view->view,
+        MainViewModel * model,
+        {
+            UNUSED(model);
+            lightmeter_main_view->cb_right = callback;
+            lightmeter_main_view->cb_context = context;
+        },
+        true);
+}
+
+static void main_view_draw_callback(Canvas* canvas, void* context) {
+    furi_assert(context);
+    MainViewModel* model = context;
+
+    canvas_clear(canvas);
+
+    // draw button
+    canvas_set_font(canvas, FontSecondary);
+    elements_button_left(canvas, "Config");
+
+    if(!model->lux_only) {
+        // top row
+        draw_top_row(canvas, model);
+
+        // add f, T values
+        canvas_set_font(canvas, FontBigNumbers);
+
+        // draw f icon and number
+        canvas_draw_icon(canvas, 15, 17, &I_f_10x14);
+        draw_aperture(canvas, model);
+
+        // draw T icon and number
+        canvas_draw_icon(canvas, 15, 34, &I_T_10x14);
+        draw_speed(canvas, model);
+
+        // draw ND number
+        draw_nd_number(canvas, model);
+
+        // draw EV number
+        canvas_set_font(canvas, FontSecondary);
+        draw_EV_number(canvas, model);
+
+        // draw mode indicator
+        draw_mode_indicator(canvas, model);
+    } else {
+        elements_button_right(canvas, "Reset");
+        draw_lux_only_mode(canvas, model);
+    }
+}
+
+static void main_view_process(MainView* main_view, InputEvent* event) {
+    with_view_model(
+        main_view->view,
+        MainViewModel * model,
+        {
+            if(event->type == InputTypePress) {
+                if(event->key == InputKeyUp) {
+                    switch(model->current_mode) {
+                    case FIXED_APERTURE:
+                        if(model->aperture < AP_NUM - 1) model->aperture++;
+                        break;
+
+                    case FIXED_SPEED:
+                        if(model->speed < SPEED_NUM - 1) model->speed++;
+                        break;
+
+                    default:
+                        break;
+                    }
+                } else if(event->key == InputKeyDown) {
+                    switch(model->current_mode) {
+                    case FIXED_APERTURE:
+                        if(model->aperture > 0) model->aperture--;
+                        break;
+
+                    case FIXED_SPEED:
+                        if(model->speed > 0) model->speed--;
+                        break;
+
+                    default:
+                        break;
+                    }
+                } else if(event->key == InputKeyOk) {
+                    switch(model->current_mode) {
+                    case FIXED_SPEED:
+                        model->current_mode = FIXED_APERTURE;
+                        break;
+
+                    case FIXED_APERTURE:
+                        model->current_mode = FIXED_SPEED;
+                        break;
+
+                    default:
+                        break;
+                    }
+                }
+            }
+        },
+        true);
+}
+
+static bool main_view_input_callback(InputEvent* event, void* context) {
+    furi_assert(context);
+    MainView* main_view = context;
+    bool consumed = false;
+
+    if(event->type == InputTypeShort && event->key == InputKeyLeft) {
+        if(main_view->cb_left) {
+            main_view->cb_left(main_view->cb_context);
+        }
+        consumed = true;
+    } else if(event->type == InputTypeShort && event->key == InputKeyRight) {
+        if(main_view->cb_right) {
+            main_view->cb_right(main_view->cb_context);
+        }
+        consumed = true;
+    } else if(event->type == InputTypeShort && event->key == InputKeyBack) {
+    } else {
+        main_view_process(main_view, event);
+        consumed = true;
+    }
+
+    return consumed;
+}
+
+MainView* main_view_alloc() {
+    MainView* main_view = malloc(sizeof(MainView));
+    main_view->view = view_alloc();
+    view_set_context(main_view->view, main_view);
+    view_allocate_model(main_view->view, ViewModelTypeLocking, sizeof(MainViewModel));
+    view_set_draw_callback(main_view->view, main_view_draw_callback);
+    view_set_input_callback(main_view->view, main_view_input_callback);
+
+    return main_view;
+}
+
+void main_view_free(MainView* main_view) {
+    furi_assert(main_view);
+    view_free(main_view->view);
+    free(main_view);
+}
+
+View* main_view_get_view(MainView* main_view) {
+    furi_assert(main_view);
+    return main_view->view;
+}
+
+void main_view_set_lux(MainView* main_view, float val) {
+    furi_assert(main_view);
+    with_view_model(
+        main_view->view,
+        MainViewModel * model,
+        {
+            model->lux = val;
+            model->peakLux = fmax(model->peakLux, val);
+
+            model->luxHistogram[model->luxHistogramIndex++] = val;
+            model->luxHistogramIndex %= LUX_HISTORGRAM_LENGTH;
+        },
+        true);
+}
+
+void main_view_reset_lux(MainView* main_view) {
+    furi_assert(main_view);
+    with_view_model(
+        main_view->view, MainViewModel * model, { model->peakLux = 0; }, true);
+}
+
+void main_view_set_EV(MainView* main_view, float val) {
+    furi_assert(main_view);
+    with_view_model(
+        main_view->view, MainViewModel * model, { model->EV = val; }, true);
+}
+
+void main_view_set_response(MainView* main_view, bool val) {
+    furi_assert(main_view);
+    with_view_model(
+        main_view->view, MainViewModel * model, { model->response = val; }, true);
+}
+
+void main_view_set_iso(MainView* main_view, int iso) {
+    furi_assert(main_view);
+    with_view_model(
+        main_view->view, MainViewModel * model, { model->iso = iso; }, true);
+}
+
+void main_view_set_nd(MainView* main_view, int nd) {
+    furi_assert(main_view);
+    with_view_model(
+        main_view->view, MainViewModel * model, { model->nd = nd; }, true);
+}
+
+void main_view_set_aperture(MainView* main_view, int aperture) {
+    furi_assert(main_view);
+    with_view_model(
+        main_view->view, MainViewModel * model, { model->aperture = aperture; }, true);
+}
+
+void main_view_set_speed(MainView* main_view, int speed) {
+    furi_assert(main_view);
+    with_view_model(
+        main_view->view, MainViewModel * model, { model->speed = speed; }, true);
+}
+
+void main_view_set_dome(MainView* main_view, bool dome) {
+    furi_assert(main_view);
+    with_view_model(
+        main_view->view, MainViewModel * model, { model->dome = dome; }, true);
+}
+
+void main_view_set_lux_only(MainView* main_view, bool lux_only) {
+    furi_assert(main_view);
+    with_view_model(
+        main_view->view, MainViewModel * model, { model->lux_only = lux_only; }, true);
+}
+
+void main_view_set_measurement_resolution(MainView* main_view, int measurement_resolution) {
+    furi_assert(main_view);
+    with_view_model(
+        main_view->view,
+        MainViewModel * model,
+        { model->measurement_resolution = measurement_resolution; },
+        true);
+}
+
+void main_view_set_device_addr(MainView* main_view, int device_addr) {
+    furi_assert(main_view);
+    with_view_model(
+        main_view->view, MainViewModel * model, { model->device_addr = device_addr; }, true);
+}
+
+void main_view_set_sensor_type(MainView* main_view, int sensor_type) {
+    furi_assert(main_view);
+    with_view_model(
+        main_view->view, MainViewModel * model, { model->sensor_type = sensor_type; }, true);
+}
+
+bool main_view_get_dome(MainView* main_view) {
+    furi_assert(main_view);
+    bool val = false;
+    with_view_model(
+        main_view->view, MainViewModel * model, { val = model->dome; }, true);
+    return val;
+}
+
+void draw_top_row(Canvas* canvas, MainViewModel* context) {
+    MainViewModel* model = context;
+
+    char str[12];
+
+    if(!model->response) {
+        canvas_draw_box(canvas, 0, 0, 128, 12);
+        canvas_set_color(canvas, ColorWhite);
+        canvas_set_font(canvas, FontPrimary);
+        canvas_draw_str(canvas, 24, 10, "No sensor found");
+        canvas_set_color(canvas, ColorBlack);
+    } else {
+        model->iso_val = iso_numbers[model->iso];
+        if(model->nd > 0) model->iso_val /= nd_numbers[model->nd];
+
+        if(model->lux > 0) {
+            if(model->current_mode == FIXED_APERTURE) {
+                model->speed_val = 100 * pow(aperture_numbers[model->aperture], 2) /
+                                   (double)model->iso_val / pow(2, model->EV);
+            } else {
+                model->aperture_val = sqrt(
+                    pow(2, model->EV) * (double)model->iso_val *
+                    (double)speed_numbers[model->speed] / 100);
+            }
+        }
+
+        // TODO when T:30, f/0 instead of f/128
+
+        canvas_draw_line(canvas, 0, 10, 128, 10);
+
+        canvas_set_font(canvas, FontPrimary);
+        // metering mode A – ambient, F – flash
+        // canvas_draw_str_aligned(canvas, 1, 1, AlignLeft, AlignTop, "A");
+
+        snprintf(str, sizeof(str), "ISO: %d", iso_numbers[model->iso]);
+        canvas_draw_str_aligned(canvas, 19, 1, AlignLeft, AlignTop, str);
+
+        canvas_set_font(canvas, FontSecondary);
+        snprintf(str, sizeof(str), "lx: %.0f", (double)model->lux);
+        canvas_draw_str_aligned(canvas, 87, 2, AlignLeft, AlignTop, str);
+    }
+}
+
+void draw_aperture(Canvas* canvas, MainViewModel* context) {
+    MainViewModel* model = context;
+
+    char str[12];
+
+    switch(model->current_mode) {
+    case FIXED_APERTURE:
+        if(model->response) {
+            if(model->aperture < AP_8) {
+                snprintf(str, sizeof(str), "/%.1f", (double)aperture_numbers[model->aperture]);
+            } else {
+                snprintf(str, sizeof(str), "/%.0f", (double)aperture_numbers[model->aperture]);
+            }
+        } else {
+            snprintf(str, sizeof(str), " ---");
+        }
+        canvas_draw_str_aligned(canvas, 27, 15, AlignLeft, AlignTop, str);
+        break;
+    case FIXED_SPEED:
+        if(model->aperture_val < aperture_numbers[0] || !model->response) {
+            snprintf(str, sizeof(str), " ---");
+        } else if(model->aperture_val < aperture_numbers[AP_8]) {
+            snprintf(str, sizeof(str), "/%.1f", (double)normalizeAperture(model->aperture_val));
+        } else {
+            snprintf(str, sizeof(str), "/%.0f", (double)normalizeAperture(model->aperture_val));
+        }
+        canvas_draw_str_aligned(canvas, 27, 15, AlignLeft, AlignTop, str);
+        break;
+    default:
+        break;
+    }
+}
+
+void draw_speed(Canvas* canvas, MainViewModel* context) {
+    MainViewModel* model = context;
+
+    char str[12];
+
+    switch(model->current_mode) {
+    case FIXED_APERTURE:
+        if(model->lux > 0 && model->response) {
+            if(model->speed_val < 1 && model->speed_val > 0) {
+                snprintf(str, sizeof(str), ":1/%.0f", 1 / (double)normalizeTime(model->speed_val));
+            } else {
+                snprintf(str, sizeof(str), ":%.0f", (double)normalizeTime(model->speed_val));
+            }
+        } else {
+            snprintf(str, sizeof(str), " ---");
+        }
+        canvas_draw_str_aligned(canvas, 27, 34, AlignLeft, AlignTop, str);
+        break;
+
+    case FIXED_SPEED:
+        if(model->response) {
+            if(model->speed < SPEED_1S) {
+                snprintf(str, sizeof(str), ":1/%.0f", 1 / (double)speed_numbers[model->speed]);
+            } else {
+                snprintf(str, sizeof(str), ":%.0f", (double)speed_numbers[model->speed]);
+            }
+        } else {
+            snprintf(str, sizeof(str), " ---");
+        }
+        canvas_draw_str_aligned(canvas, 27, 34, AlignLeft, AlignTop, str);
+        break;
+
+    default:
+        break;
+    }
+}
+
+void draw_mode_indicator(Canvas* canvas, MainViewModel* context) {
+    MainViewModel* model = context;
+
+    switch(model->current_mode) {
+    case FIXED_SPEED:
+        canvas_set_font(canvas, FontBigNumbers);
+        canvas_draw_str_aligned(canvas, 3, 36, AlignLeft, AlignTop, "*");
+        break;
+
+    case FIXED_APERTURE:
+        canvas_set_font(canvas, FontBigNumbers);
+        canvas_draw_str_aligned(canvas, 3, 17, AlignLeft, AlignTop, "*");
+        break;
+
+    default:
+        break;
+    }
+}
+
+void draw_nd_number(Canvas* canvas, MainViewModel* context) {
+    MainViewModel* model = context;
+
+    char str[9];
+
+    canvas_set_font(canvas, FontSecondary);
+
+    if(model->response) {
+        snprintf(str, sizeof(str), "ND: %d", nd_numbers[model->nd]);
+    } else {
+        snprintf(str, sizeof(str), "ND: ---");
+    }
+    canvas_draw_str_aligned(canvas, 87, 20, AlignLeft, AlignBottom, str);
+}
+
+void draw_EV_number(Canvas* canvas, MainViewModel* context) {
+    MainViewModel* model = context;
+
+    char str[7];
+
+    if(model->lux > 0 && model->response) {
+        snprintf(str, sizeof(str), "EV: %1.0f", (double)model->EV);
+        canvas_draw_str_aligned(canvas, 87, 29, AlignLeft, AlignBottom, str);
+    } else {
+        canvas_draw_str_aligned(canvas, 87, 29, AlignLeft, AlignBottom, "EV: --");
+    }
+}
+
+void draw_lux_only_mode(Canvas* canvas, MainViewModel* context) {
+    MainViewModel* model = context;
+
+    if(!model->response) {
+        canvas_draw_box(canvas, 0, 0, 128, 12);
+        canvas_set_color(canvas, ColorWhite);
+        canvas_set_font(canvas, FontPrimary);
+        canvas_draw_str(canvas, 24, 10, "No sensor found");
+        canvas_set_color(canvas, ColorBlack);
+    } else {
+        char str[12];
+
+        canvas_set_font(canvas, FontPrimary);
+
+        canvas_draw_line(canvas, 0, 10, 128, 10);
+        canvas_draw_str_aligned(canvas, 64, 1, AlignCenter, AlignTop, "Lux meter mode");
+
+        canvas_set_font(canvas, FontBigNumbers);
+        snprintf(str, sizeof(str), "%.0f", (double)model->lux);
+        canvas_draw_str_aligned(canvas, 80, 22, AlignRight, AlignCenter, str);
+
+        canvas_set_font(canvas, FontSecondary);
+        canvas_draw_str_aligned(canvas, 85, 29, AlignLeft, AlignBottom, "Lux now");
+
+        canvas_set_font(canvas, FontPrimary);
+        snprintf(str, sizeof(str), "%.0f", (double)model->peakLux);
+        canvas_draw_str_aligned(canvas, 80, 39, AlignRight, AlignCenter, str);
+
+        canvas_set_font(canvas, FontSecondary);
+        canvas_draw_str_aligned(canvas, 85, 43, AlignLeft, AlignBottom, "Lux peak");
+
+        for(int i = 0; i < LUX_HISTORGRAM_LENGTH; i++) {
+            float lux =
+                model->luxHistogram[(i + model->luxHistogramIndex) % LUX_HISTORGRAM_LENGTH];
+            int barHeight = log10(lux) / log10(LUX_HISTORGRAM_LOGBASE);
+            canvas_draw_line(
+                canvas,
+                LUX_HISTORGRAM_LEFT + i,
+                LUX_HISTORGRAM_BOTTOM,
+                LUX_HISTORGRAM_LEFT + i,
+                LUX_HISTORGRAM_BOTTOM - barHeight);
+        }
+    }
+}

lightmeter/gui/views/main_view.h

@@ -0,0 +1,110 @@
+#pragma once
+
+#include <gui/view.h>
+#include "lightmeter_icons.h"
+#include "../../lightmeter_config.h"
+
+/* log base 1.4 and 12 pixels cut off
+   makes it show values approx 65-65k
+   with reasonable resolution in 1-10k range
+   on 20px of screen height  */
+#define LUX_HISTORGRAM_LOGBASE 1.4
+#define LUX_HISTORGRAM_BOTTOM 64 + 12
+
+/* 40 pixels between 45th and 85th
+   between left and right button labels */
+#define LUX_HISTORGRAM_LEFT 45
+#define LUX_HISTORGRAM_LENGTH 40
+
+typedef struct MainView MainView;
+
+typedef enum {
+    FIXED_APERTURE,
+    FIXED_SPEED,
+
+    MODES_SIZE
+} MainViewMode;
+
+typedef struct {
+    uint8_t recv[2];
+    MainViewMode current_mode;
+    float lux;
+    float peakLux;
+    float EV;
+    float aperture_val;
+    float speed_val;
+    int iso_val;
+    bool response;
+    int iso;
+    int nd;
+    int aperture;
+    int speed;
+    bool dome;
+    bool lux_only;
+    int measurement_resolution;
+    int device_addr;
+    int sensor_type;
+
+    float luxHistogram[LUX_HISTORGRAM_LENGTH];
+    int luxHistogramIndex;
+} MainViewModel;
+
+typedef void (*LightMeterMainViewButtonCallback)(void* context);
+
+void lightmeter_main_view_set_left_callback(
+    MainView* lightmeter_main_view,
+    LightMeterMainViewButtonCallback callback,
+    void* context);
+
+void lightmeter_main_view_set_right_callback(
+    MainView* lightmeter_main_view,
+    LightMeterMainViewButtonCallback callback,
+    void* context);
+
+MainView* main_view_alloc();
+
+void main_view_free(MainView* main_view);
+
+View* main_view_get_view(MainView* main_view);
+
+void main_view_set_lux(MainView* main_view, float val);
+
+void main_view_reset_lux(MainView* main_view);
+
+void main_view_set_EV(MainView* main_view_, float val);
+
+void main_view_set_response(MainView* main_view_, bool val);
+
+void main_view_set_iso(MainView* main_view, int val);
+
+void main_view_set_nd(MainView* main_view, int val);
+
+void main_view_set_aperture(MainView* main_view, int val);
+
+void main_view_set_speed(MainView* main_view, int val);
+
+void main_view_set_dome(MainView* main_view, bool val);
+
+void main_view_set_lux_only(MainView* main_view, bool val);
+
+void main_view_set_measurement_resolution(MainView* main_view, int val);
+
+void main_view_set_device_addr(MainView* main_view, int addr);
+
+void main_view_set_sensor_type(MainView* main_view, int sensor_type);
+
+bool main_view_get_dome(MainView* main_view);
+
+void draw_top_row(Canvas* canvas, MainViewModel* context);
+
+void draw_aperture(Canvas* canvas, MainViewModel* context);
+
+void draw_speed(Canvas* canvas, MainViewModel* context);
+
+void draw_mode_indicator(Canvas* canvas, MainViewModel* context);
+
+void draw_nd_number(Canvas* canvas, MainViewModel* context);
+
+void draw_EV_number(Canvas* canvas, MainViewModel* context);
+
+void draw_lux_only_mode(Canvas* canvas, MainViewModel* context);

lightmeter/lib/BH1750

@@ -0,0 +1 @@
+Subproject commit cf05c49076a54dc0559d193e5aec29ff7455aa65

lightmeter/lib/MAX44009/MAX44009.c

@@ -0,0 +1,35 @@
+#include <MAX44009.h>
+#include <math.h>
+#include <furi.h>
+
+uint8_t max44009_addr = MAX44009_ADDR;
+
+void max44009_init() {
+    furi_hal_i2c_acquire(I2C_BUS);
+    furi_hal_i2c_write_reg_8(
+        I2C_BUS, max44009_addr, MAX44009_REG_CONFIG, MAX44009_REG_CONFIG_CONT_MODE, I2C_TIMEOUT);
+    furi_hal_i2c_release(I2C_BUS);
+}
+
+void max44009_init_with_addr(uint8_t addr) {
+    max44009_addr = (addr << 1);
+    return max44009_init();
+}
+
+int max44009_read_light(float* result) {
+    uint8_t data_one = 0;
+    uint8_t exp, mantissa;
+    int status;
+
+    furi_hal_i2c_acquire(I2C_BUS);
+    furi_hal_i2c_read_reg_8(I2C_BUS, MAX44009_ADDR, MAX44009_REG_LUX_HI, &data_one, I2C_TIMEOUT);
+    exp = (data_one & MAX44009_REG_LUX_HI_EXP_MASK) >> 4;
+    mantissa = (data_one & MAX44009_REG_LUX_HI_MANT_HI_MASK) << 4;
+    status = furi_hal_i2c_read_reg_8(
+        I2C_BUS, MAX44009_ADDR, MAX44009_REG_LUX_LO, &data_one, I2C_TIMEOUT);
+    mantissa |= (data_one & MAX44009_REG_LUX_LO_MANT_LO_MASK);
+    furi_hal_i2c_release(I2C_BUS);
+    *result = (float)pow(2, exp) * mantissa * 0.045;
+    FURI_LOG_D("MAX44009", "exp %d, mant %d, lux %f", exp, mantissa, (double)*result);
+    return status;
+}

lightmeter/lib/MAX44009/MAX44009.h

@@ -0,0 +1,27 @@
+#include <furi.h>
+#include <furi_hal.h>
+
+#pragma once
+
+// I2C BUS
+#define I2C_BUS &furi_hal_i2c_handle_external
+#define I2C_TIMEOUT 10
+
+#define MAX44009_ADDR (0x4A << 1)
+
+#define MAX44009_REG_INT_STATUS 0x00
+#define MAX44009_REG_INT_EN 0x01
+#define MAX44009_REG_CONFIG 0x02
+#define MAX44009_REG_CONFIG_CONT_MODE (1 << 7)
+#define MAX44009_REG_LUX_HI 0x03
+#define MAX44009_REG_LUX_HI_EXP_MASK 0xF0
+#define MAX44009_REG_LUX_HI_MANT_HI_MASK 0x0F
+#define MAX44009_REG_LUX_LO 0x04
+#define MAX44009_REG_LUX_LO_MANT_LO_MASK 0x0F
+#define MAX44009_REG_THRESH_HI 0x05
+#define MAX44009_REG_THRESH_LO 0x06
+#define MAX44009_REG_INT_TIME 0x07
+
+void max44009_init();
+void max44009_init_with_addr(uint8_t addr);
+int max44009_read_light(float* result);

lightmeter/lightmeter.c

@@ -0,0 +1,259 @@
+#include "lightmeter.h"
+#include "lightmeter_helper.h"
+
+#define TAG "MAIN APP"
+
+static bool lightmeter_custom_event_callback(void* context, uint32_t event) {
+    furi_assert(context);
+    LightMeterApp* app = context;
+
+    return scene_manager_handle_custom_event(app->scene_manager, event);
+}
+
+static bool lightmeter_back_event_callback(void* context) {
+    furi_assert(context);
+    LightMeterApp* app = context;
+
+    return scene_manager_handle_back_event(app->scene_manager);
+}
+
+static void lightmeter_tick_event_callback(void* context) {
+    furi_assert(context);
+    LightMeterApp* app = context;
+
+    scene_manager_handle_tick_event(app->scene_manager);
+}
+
+LightMeterApp* lightmeter_app_alloc(uint32_t first_scene) {
+    LightMeterApp* app = malloc(sizeof(LightMeterApp));
+
+    // Set default values to config
+    app->config = malloc(sizeof(LightMeterConfig));
+    app->config->iso = DEFAULT_ISO;
+    app->config->nd = DEFAULT_ND;
+    app->config->aperture = DEFAULT_APERTURE;
+    app->config->dome = DEFAULT_DOME;
+    app->config->backlight = DEFAULT_BACKLIGHT;
+    app->config->measurement_resolution = HIGH_RES;
+    app->config->device_addr = ADDR_LOW;
+    app->config->lux_only = LUX_ONLY_OFF;
+
+    // Records
+    app->gui = furi_record_open(RECORD_GUI);
+    app->storage = furi_record_open(RECORD_STORAGE);
+    app->notifications = furi_record_open(RECORD_NOTIFICATION);
+
+    app->cfg_path = furi_string_alloc();
+    furi_string_printf(app->cfg_path, "%s/%s", APP_PATH_DIR, APP_PATH_CFG);
+
+    FlipperFormat* cfg_fmt = flipper_format_file_alloc(app->storage);
+    if(flipper_format_file_open_existing(cfg_fmt, furi_string_get_cstr(app->cfg_path))) {
+        flipper_format_read_int32(cfg_fmt, "iso", &app->config->iso, 1);
+        flipper_format_read_int32(cfg_fmt, "aperture", &app->config->aperture, 1);
+        flipper_format_read_int32(cfg_fmt, "dome", &app->config->dome, 1);
+        flipper_format_read_int32(cfg_fmt, "backlight", &app->config->backlight, 1);
+        flipper_format_read_int32(
+            cfg_fmt, "measurement_resolution", &app->config->measurement_resolution, 1);
+        flipper_format_read_int32(cfg_fmt, "lux_only", &app->config->lux_only, 1);
+        flipper_format_read_int32(cfg_fmt, "device_addr", &app->config->device_addr, 1);
+        flipper_format_read_int32(cfg_fmt, "sensor_type", &app->config->sensor_type, 1);
+    }
+    flipper_format_free(cfg_fmt);
+
+    // Sensor
+    lightmeter_app_i2c_init_sensor(app);
+
+    // View dispatcher
+    app->view_dispatcher = view_dispatcher_alloc();
+    app->scene_manager = scene_manager_alloc(&lightmeter_scene_handlers, app);
+    view_dispatcher_enable_queue(app->view_dispatcher);
+    view_dispatcher_set_event_callback_context(app->view_dispatcher, app);
+    view_dispatcher_set_custom_event_callback(
+        app->view_dispatcher, lightmeter_custom_event_callback);
+    view_dispatcher_set_navigation_event_callback(
+        app->view_dispatcher, lightmeter_back_event_callback);
+    view_dispatcher_set_tick_event_callback(
+        app->view_dispatcher, lightmeter_tick_event_callback, furi_ms_to_ticks(200));
+    view_dispatcher_attach_to_gui(app->view_dispatcher, app->gui, ViewDispatcherTypeFullscreen);
+
+    // Views
+    app->main_view = main_view_alloc();
+    view_dispatcher_add_view(
+        app->view_dispatcher, LightMeterAppViewMainView, main_view_get_view(app->main_view));
+
+    // Set default values to main view from config
+    main_view_set_iso(app->main_view, app->config->iso);
+    main_view_set_nd(app->main_view, app->config->nd);
+    main_view_set_aperture(app->main_view, app->config->aperture);
+    main_view_set_speed(app->main_view, DEFAULT_SPEED);
+    main_view_set_dome(app->main_view, app->config->dome);
+
+    // Variable item list
+    app->var_item_list = variable_item_list_alloc();
+    view_dispatcher_add_view(
+        app->view_dispatcher,
+        LightMeterAppViewVarItemList,
+        variable_item_list_get_view(app->var_item_list));
+
+    // Widget
+    app->widget = widget_alloc();
+    view_dispatcher_add_view(
+        app->view_dispatcher, LightMeterAppViewAbout, widget_get_view(app->widget));
+    view_dispatcher_add_view(
+        app->view_dispatcher, LightMeterAppViewHelp, widget_get_view(app->widget));
+
+    // Set first scene
+    scene_manager_next_scene(app->scene_manager, first_scene);
+    return app;
+}
+
+void lightmeter_app_free(LightMeterApp* app) {
+    furi_assert(app);
+
+    // Views
+    view_dispatcher_remove_view(app->view_dispatcher, LightMeterAppViewMainView);
+    main_view_free(app->main_view);
+
+    // Variable item list
+    view_dispatcher_remove_view(app->view_dispatcher, LightMeterAppViewVarItemList);
+    variable_item_list_free(app->var_item_list);
+
+    //  Widget
+    view_dispatcher_remove_view(app->view_dispatcher, LightMeterAppViewAbout);
+    view_dispatcher_remove_view(app->view_dispatcher, LightMeterAppViewHelp);
+    widget_free(app->widget);
+
+    // View dispatcher
+    scene_manager_free(app->scene_manager);
+    view_dispatcher_free(app->view_dispatcher);
+
+    // Records
+    furi_record_close(RECORD_GUI);
+    if(app->config->backlight != BACKLIGHT_AUTO) {
+        notification_message(
+            app->notifications,
+            &sequence_display_backlight_enforce_auto); // set backlight back to auto
+    }
+    furi_record_close(RECORD_STORAGE);
+    furi_record_close(RECORD_NOTIFICATION);
+
+    bh1750_set_power_state(0);
+
+    free(app->config);
+    free(app);
+}
+
+int32_t lightmeter_app(void* p) {
+    UNUSED(p);
+    uint32_t first_scene = LightMeterAppSceneMain;
+    LightMeterApp* app = lightmeter_app_alloc(first_scene);
+    view_dispatcher_run(app->view_dispatcher);
+    lightmeter_app_free(app);
+    return 0;
+}
+
+void lightmeter_app_set_config(LightMeterApp* context, LightMeterConfig* config) {
+    LightMeterApp* app = context;
+
+    app->config = config;
+    storage_common_mkdir(app->storage, APP_PATH_DIR);
+
+    FlipperFormat* cfg_fmt = flipper_format_file_alloc(app->storage);
+    if(flipper_format_file_open_always(cfg_fmt, furi_string_get_cstr(app->cfg_path))) {
+        flipper_format_write_header_cstr(cfg_fmt, "lightmeter", 1);
+
+        flipper_format_write_int32(cfg_fmt, "iso", &(app->config->iso), 1);
+        flipper_format_write_int32(cfg_fmt, "nd", &(app->config->nd), 1);
+        flipper_format_write_int32(cfg_fmt, "aperture", &(app->config->aperture), 1);
+        flipper_format_write_int32(cfg_fmt, "dome", &(app->config->dome), 1);
+        flipper_format_write_int32(cfg_fmt, "backlight", &(app->config->backlight), 1);
+        flipper_format_write_int32(
+            cfg_fmt, "measurement_resolution", &(app->config->measurement_resolution), 1);
+        flipper_format_write_int32(cfg_fmt, "lux_only", &(app->config->lux_only), 1);
+        flipper_format_write_int32(cfg_fmt, "device_addr", &(app->config->device_addr), 1);
+        flipper_format_write_int32(cfg_fmt, "sensor_type", &(app->config->sensor_type), 1);
+    }
+    flipper_format_free(cfg_fmt);
+}
+
+void lightmeter_app_i2c_init_sensor(LightMeterApp* context) {
+    LightMeterApp* app = context;
+    switch(app->config->sensor_type) {
+    case SENSOR_BH1750:
+        bh1750_set_power_state(1);
+        switch(app->config->device_addr) {
+        case ADDR_HIGH:
+            bh1750_init_with_addr(0x5C);
+            break;
+        case ADDR_LOW:
+            bh1750_init_with_addr(0x23);
+            break;
+        default:
+            bh1750_init_with_addr(0x23);
+            break;
+        }
+        bh1750_set_mode(ONETIME_HIGH_RES_MODE);
+        break;
+    case SENSOR_MAX44009:
+        switch(app->config->device_addr) {
+        case ADDR_HIGH:
+            max44009_init_with_addr(0x4B);
+            break;
+        case ADDR_LOW:
+            max44009_init_with_addr(0x4A);
+            break;
+        default:
+            max44009_init_with_addr(0x4A);
+            break;
+        }
+        break;
+    default:
+        FURI_LOG_E(TAG, "Invalid sensor type %ld", app->config->sensor_type);
+        return;
+    }
+}
+
+void lightmeter_app_i2c_deinit_sensor(LightMeterApp* context) {
+    LightMeterApp* app = context;
+    switch(app->config->sensor_type) {
+    case SENSOR_BH1750:
+        bh1750_set_power_state(0);
+        break;
+    case SENSOR_MAX44009:
+        // nothing
+        break;
+    default:
+        FURI_LOG_E(TAG, "Invalid sensor type %ld", app->config->sensor_type);
+        return;
+    }
+}
+
+void lightmeter_app_i2c_callback(LightMeterApp* context) {
+    LightMeterApp* app = context;
+
+    float EV = 0;
+    float lux = 0;
+    bool response = 0;
+
+    if(app->config->sensor_type == SENSOR_BH1750) {
+        if(bh1750_trigger_manual_conversion() == BH1750_OK) {
+            bh1750_read_light(&lux);
+            response = 1;
+        }
+    } else if(app->config->sensor_type == SENSOR_MAX44009) {
+        if(max44009_read_light(&lux)) response = 1;
+    }
+
+    if(main_view_get_dome(app->main_view)) lux *= DOME_COEFFICIENT;
+    EV = lux2ev(lux);
+
+    main_view_set_lux(app->main_view, lux);
+    main_view_set_EV(app->main_view, EV);
+    main_view_set_response(app->main_view, response);
+}
+
+void lightmeter_app_reset_callback(LightMeterApp* context) {
+    LightMeterApp* app = context;
+
+    main_view_reset_lux(app->main_view);
+}

lightmeter/lightmeter.h

@@ -0,0 +1,79 @@
+#pragma once
+
+#include <furi.h>
+#include <furi_hal.h>
+
+#include <stream/stream.h>
+#include <flipper_format/flipper_format_i.h>
+
+#include <gui/gui.h>
+#include <gui/view.h>
+#include <gui/view_dispatcher.h>
+#include <gui/scene_manager.h>
+
+#include "gui/views/main_view.h"
+
+#include <gui/modules/widget.h>
+#include <gui/modules/variable_item_list.h>
+
+#include "gui/scenes/config/lightmeter_scene.h"
+#include <notification/notification_messages.h>
+
+#include "lightmeter_config.h"
+#include <BH1750.h>
+#include <MAX44009.h>
+
+#define APP_PATH_DIR STORAGE_APP_DATA_PATH_PREFIX
+#define APP_PATH_CFG "config.txt"
+
+typedef struct {
+    int32_t iso;
+    int32_t nd;
+    int32_t aperture;
+    int32_t dome;
+    int32_t backlight;
+    int32_t lux_only;
+    int32_t sensor_type;
+    int32_t measurement_resolution;
+    int32_t device_addr;
+} LightMeterConfig;
+
+typedef struct {
+    Gui* gui;
+    SceneManager* scene_manager;
+    ViewDispatcher* view_dispatcher;
+    MainView* main_view;
+    VariableItemList* var_item_list;
+    VariableItem* var_item_addr;
+    LightMeterConfig* config;
+    NotificationApp* notifications;
+    Widget* widget;
+
+    Storage* storage;
+    FuriString* cfg_path;
+} LightMeterApp;
+
+typedef enum {
+    LightMeterAppViewMainView,
+    LightMeterAppViewConfigView,
+    LightMeterAppViewVarItemList,
+    LightMeterAppViewAbout,
+    LightMeterAppViewHelp,
+} LightMeterAppView;
+
+typedef enum {
+    LightMeterAppCustomEventReset,
+    LightMeterAppCustomEventConfig,
+    LightMeterAppCustomEventHelp,
+    LightMeterAppCustomEventAbout,
+} LightMeterAppCustomEvent;
+
+void lightmeter_app_set_config(LightMeterApp* context, LightMeterConfig* config);
+
+void lightmeter_app_i2c_init_sensor(LightMeterApp* context);
+
+void lightmeter_app_i2c_deinit_sensor(LightMeterApp* context);
+
+void lightmeter_app_i2c_callback(LightMeterApp* context);
+
+void lightmeter_app_reset_callback(LightMeterApp* context);

lightmeter/lightmeter_config.h

@@ -0,0 +1,124 @@
+#pragma once
+
+#define LM_VERSION_APP "1.2"
+#define LM_DEVELOPED "Oleksii Kutuzov"
+#define LM_GITHUB "https://github.com/oleksiikutuzov/flipperzero-lightmeter"
+
+#define DOME_COEFFICIENT 2.3
+#define DEFAULT_ISO ISO_100
+#define DEFAULT_ND ND_0
+#define DEFAULT_APERTURE AP_2_8
+#define DEFAULT_SPEED SPEED_125
+#define DEFAULT_DOME WITHOUT_DOME
+#define DEFAULT_BACKLIGHT BACKLIGHT_AUTO
+
+typedef enum {
+    ISO_6,
+    ISO_12,
+    ISO_25,
+    ISO_50,
+    ISO_100,
+    ISO_200,
+    ISO_400,
+    ISO_800,
+    ISO_1600,
+    ISO_3200,
+    ISO_6400,
+    ISO_12800,
+    ISO_25600,
+    ISO_51200,
+    ISO_102400,
+
+    ISO_NUM,
+} LightMeterISONumbers;
+
+typedef enum {
+    ND_0,
+    ND_2,
+    ND_4,
+    ND_8,
+    ND_16,
+    ND_32,
+    ND_64,
+    ND_128,
+    ND_256,
+    ND_512,
+    ND_1024,
+    ND_2048,
+    ND_4096,
+
+    ND_NUM,
+} LightMeterNDNumbers;
+
+typedef enum {
+    AP_1,
+    AP_1_4,
+    AP_2,
+    AP_2_8,
+    AP_4,
+    AP_5_6,
+    AP_8,
+    AP_11,
+    AP_16,
+    AP_22,
+    AP_32,
+    AP_45,
+    AP_64,
+    AP_90,
+    AP_128,
+
+    AP_NUM,
+} LightMeterApertureNumbers;
+
+typedef enum {
+    SPEED_8000,
+    SPEED_4000,
+    SPEED_2000,
+    SPEED_1000,
+    SPEED_500,
+    SPEED_250,
+    SPEED_125,
+    SPEED_60,
+    SPEED_48,
+    SPEED_30,
+    SPEED_15,
+    SPEED_8,
+    SPEED_4,
+    SPEED_2,
+    SPEED_1S,
+    SPEED_2S,
+    SPEED_4S,
+    SPEED_8S,
+    SPEED_15S,
+    SPEED_30S,
+
+    SPEED_NUM,
+} LightMeterSpeedNumbers;
+
+typedef enum {
+    WITHOUT_DOME,
+    WITH_DOME,
+} LightMeterDomePresence;
+
+typedef enum {
+    LUX_ONLY_OFF,
+    LUX_ONLY_ON,
+} LightMeterLuxOnlyMode;
+
+typedef enum {
+    LOW_RES,
+    HIGH_RES,
+    HIGH_RES2,
+} LightMeterMeterMode;
+
+typedef enum {
+    ADDR_LOW,
+    ADDR_HIGH,
+} LightMeterMeterAddr;
+
+typedef enum {
+    SENSOR_BH1750,
+    SENSOR_MAX44009,
+} LightMeterSensorType;
+
+typedef enum { BACKLIGHT_AUTO, BACKLIGHT_ON } LightMeterBacklight;

lightmeter/lightmeter_helper.c

@@ -0,0 +1,43 @@
+#include "lightmeter_helper.h"
+#include "lightmeter_config.h"
+
+extern const float aperture_numbers[];
+extern const float speed_numbers[];
+
+float lux2ev(float lux) {
+    return log2(lux / 2.5);
+}
+
+float getMinDistance(float x, float v1, float v2) {
+    if(x - v1 > v2 - x) {
+        return v2;
+    }
+
+    return v1;
+}
+
+float normalizeAperture(float a) {
+    for(int i = 0; i < AP_NUM; i++) {
+        float a1 = aperture_numbers[i];
+        float a2 = aperture_numbers[i + 1];
+
+        if(a1 < a && a2 >= a) {
+            return getMinDistance(a, a1, a2);
+        }
+    }
+
+    return 0;
+}
+
+float normalizeTime(float a) {
+    for(int i = 0; i < SPEED_NUM; i++) {
+        float a1 = speed_numbers[i];
+        float a2 = speed_numbers[i + 1];
+
+        if(a1 < a && a2 >= a) {
+            return getMinDistance(a, a1, a2);
+        }
+    }
+
+    return 0;
+}

lightmeter/lightmeter_helper.h

@@ -0,0 +1,11 @@
+#pragma once
+
+#include <math.h>
+
+float lux2ev(float lux);
+
+float getMinDistance(float x, float v1, float v2);
+
+float normalizeAperture(float a);
+
+float normalizeTime(float a);