/* @CodeAllNight https://github.com/jamisonderek/flipper-zero-tutorials This is a demonstration of reading GPIO using polling. */ #include #include #include #include #include #include typedef enum { DemoEventTypeTick, DemoEventTypeKey, // You can add additional events here. } DemoEventType; typedef struct { DemoEventType type; // The reason for this event. InputEvent input; // This data is specific to keypress data. // You can add additional data that is helpful for your events. } DemoEvent; typedef struct { FuriString* buffer; // You can add additional state here. int counter; bool pin_grounded; } DemoData; typedef struct { FuriMessageQueue* queue; // Message queue (DemoEvent items to process). FuriMutex* mutex; // Used to provide thread safe access to data. DemoData* data; // Data accessed by multiple threads (acquire the mutex before accessing!) } DemoContext; GpioPin demo_message_pin; // This is the pin used for our GPIO demo. // Invoked when input (button press) is detected. We queue a message and then return to the caller. static void gpio_polling_demo_input_callback(InputEvent* input_event, FuriMessageQueue* queue) { furi_assert(queue); DemoEvent event = {.type = DemoEventTypeKey, .input = *input_event}; furi_message_queue_put(queue, &event, FuriWaitForever); } // Invoked by the timer on every tick. We queue a message and then return to the caller. static void gpio_polling_demo_tick(void* ctx) { furi_assert(ctx); FuriMessageQueue* queue = ctx; DemoEvent event = {.type = DemoEventTypeTick}; // It's OK to loose this event if system overloaded (so we don't pass a wait value for 3rd parameter.) furi_message_queue_put(queue, &event, 0); } // Invoked by the draw callback to render the screen. We render our UI on the callback thread. static void gpio_polling_demo_render_callback(Canvas* canvas, void* ctx) { // Attempt to aquire context, so we can read the data. DemoContext* demo_context = ctx; if(furi_mutex_acquire(demo_context->mutex, 200) != FuriStatusOk) { return; } DemoData* data = demo_context->data; bool show_hello = !data->pin_grounded; int counter = data->counter; bool even_counter = (counter & 1) == 0; // If the lowest bit is 0, then counter is even. // Other fonts are FontPrimary, FontSecondary, FontKeyboard, FontBigNumbers, canvas_set_font(canvas, FontPrimary); canvas_draw_str_aligned(canvas, 64, 31, AlignLeft, AlignCenter, (show_hello ? "HELLO" : "WORLD")); // Put the lowest 4 digits of counter value into the buffer, then concatenate the text "Even" or "Odd". furi_string_printf(data->buffer, "%04u", (counter % 10000)); furi_string_cat_printf(data->buffer, " %s", (even_counter) ? ("Even") : ("Odd")); canvas_set_font(canvas, FontSecondary); canvas_draw_str_aligned(canvas, 64, 42, AlignCenter, AlignTop, furi_string_get_cstr(data->buffer)); // Release the context, so other threads can update the data. furi_mutex_release(demo_context->mutex); // Make tones if the speaker is available. if (furi_hal_speaker_acquire(1000)) { float freq = 100.0f + (counter*4.0); float volume = 1.0f; furi_hal_speaker_start(freq, volume); furi_delay_ms(100); furi_hal_speaker_stop(); furi_hal_speaker_release(); } } // Our main loop invokes this method after acquiring the mutex, so we can safely access the protected data. // We increment a counter and update if the GPIO pin is grounded. static void gpio_polling_demo_update_pin_status(void* ctx) { DemoContext* demo_context = ctx; DemoData* data = demo_context->data; data->counter++; // read returns true for VCC and false for ground, so invert answer. data->pin_grounded = !furi_hal_gpio_read(&demo_message_pin); } int32_t gpio_polling_demo_app(void* p) { UNUSED(p); // Configure our initial data. DemoContext* demo_context = malloc(sizeof(DemoContext)); demo_context->mutex = furi_mutex_alloc(FuriMutexTypeNormal); demo_context->data = malloc(sizeof(DemoData)); demo_context->data->buffer = furi_string_alloc(); demo_context->data->counter = 0; demo_context->data->pin_grounded = false; // For this demo we are using pin "gpio_ext_pa4" from \firmware\targets\f7\furi_hal\furi_hal_resources.c demo_message_pin = gpio_ext_pa4; furi_hal_gpio_init(&demo_message_pin, GpioModeInput, GpioPullUp, GpioSpeedVeryHigh); // Queue for events (tick or input) demo_context->queue = furi_message_queue_alloc(8, sizeof(DemoEvent)); // Set ViewPort callbacks ViewPort* view_port = view_port_alloc(); view_port_draw_callback_set(view_port, gpio_polling_demo_render_callback, demo_context); view_port_input_callback_set(view_port, gpio_polling_demo_input_callback, demo_context->queue); // Open GUI and register view_port Gui* gui = furi_record_open(RECORD_GUI); gui_add_view_port(gui, view_port, GuiLayerFullscreen); // Update the screen fairly frequently (every 250 milliseconds.) FuriTimer* timer = furi_timer_alloc(gpio_polling_demo_tick, FuriTimerTypePeriodic, demo_context->queue); furi_timer_start(timer, 250); // Main loop DemoEvent event; bool processing = true; do { if (furi_message_queue_get(demo_context->queue, &event, FuriWaitForever) == FuriStatusOk) { switch (event.type) { case DemoEventTypeKey: // Short press of back button exits the program. if(event.input.type == InputTypeShort && event.input.key == InputKeyBack) { processing = false; } break; case DemoEventTypeTick: // Every timer tick we update the pin status. furi_mutex_acquire(demo_context->mutex, FuriWaitForever); gpio_polling_demo_update_pin_status(demo_context); furi_mutex_release(demo_context->mutex); break; default: break; } // Send signal to update the screen (callback will get invoked at some point later.) view_port_update(view_port); } else { // We had an issue getting message from the queue, so exit application. processing = false; } } while (processing); // Make pin float on exit. furi_hal_gpio_init(&demo_message_pin, GpioModeInput, GpioPullNo, GpioSpeedVeryHigh); // Free resources furi_timer_free(timer); view_port_enabled_set(view_port, false); gui_remove_view_port(gui, view_port); view_port_free(view_port); furi_record_close(RECORD_GUI); furi_message_queue_free(demo_context->queue); furi_mutex_free(demo_context->mutex); furi_string_free(demo_context->data->buffer); free(demo_context->data); free(demo_context); return 0; }