[FL-3880] Fix cumulative error in infrared signals (#3823)

* Correct for pulse duration cumulative discrepancy
* Add infrared test application
* Build infrared_test_app for f7 only

Co-authored-by: あく <alleteam@gmail.com>

applications/debug/infrared_test/application.fam

@@ -0,0 +1,8 @@
+App(
+    appid="infrared_test",
+    name="Infrared Test",
+    apptype=FlipperAppType.DEBUG,
+    entry_point="infrared_test_app",
+    fap_category="Debug",
+    targets=["f7"],
+)

applications/debug/infrared_test/infrared_test.c

@@ -0,0 +1,61 @@
+#include <furi.h>
+#include <furi_hal_infrared.h>
+
+#define TAG "InfraredTest"
+
+#define CARRIER_FREQ_HZ (38000UL)
+#define CARRIER_DUTY    (0.33f)
+
+#define BURST_DURATION_US (600UL)
+#define BURST_COUNT       (50UL)
+
+typedef struct {
+    bool level;
+    uint32_t count;
+} InfraredTestApp;
+
+static FuriHalInfraredTxGetDataState
+    infrared_test_app_tx_data_callback(void* context, uint32_t* duration, bool* level) {
+    furi_assert(context);
+    furi_assert(duration);
+    furi_assert(level);
+
+    InfraredTestApp* app = context;
+
+    *duration = BURST_DURATION_US;
+    *level = app->level;
+
+    app->level = !app->level;
+    app->count += 1;
+
+    if(app->count < BURST_COUNT * 2) {
+        return FuriHalInfraredTxGetDataStateOk;
+    } else {
+        return FuriHalInfraredTxGetDataStateLastDone;
+    }
+}
+
+int32_t infrared_test_app(void* arg) {
+    UNUSED(arg);
+
+    InfraredTestApp app = {
+        .level = true,
+    };
+
+    FURI_LOG_I(TAG, "Starting test signal on PA7");
+
+    furi_hal_infrared_set_tx_output(FuriHalInfraredTxPinExtPA7);
+    furi_hal_infrared_async_tx_set_data_isr_callback(infrared_test_app_tx_data_callback, &app);
+    furi_hal_infrared_async_tx_start(CARRIER_FREQ_HZ, CARRIER_DUTY);
+    furi_hal_infrared_async_tx_wait_termination();
+    furi_hal_infrared_set_tx_output(FuriHalInfraredTxPinInternal);
+
+    FURI_LOG_I(TAG, "Test signal end");
+    FURI_LOG_I(
+        TAG,
+        "The measured signal should be %luus +-%.1fus",
+        (app.count - 1) * BURST_DURATION_US,
+        (double)1000000.0 / CARRIER_FREQ_HZ);
+
+    return 0;
+}

targets/f7/furi_hal/furi_hal_infrared.c

@@ -54,6 +54,7 @@ typedef struct {
 
 typedef struct {
     float cycle_duration;
+    float cycle_remainder;
     FuriHalInfraredTxGetDataISRCallback data_callback;
     FuriHalInfraredTxSignalSentISRCallback signal_sent_callback;
     void* data_context;
@@ -512,7 +513,11 @@ static void furi_hal_infrared_tx_fill_buffer(uint8_t buf_num, uint8_t polarity_s
 
         status = infrared_tim_tx.data_callback(infrared_tim_tx.data_context, &duration, &level);
 
-        uint32_t num_of_impulses = roundf(duration / infrared_tim_tx.cycle_duration);
+        const float num_of_impulses_f =
+            duration / infrared_tim_tx.cycle_duration + infrared_tim_tx.cycle_remainder;
+        const uint32_t num_of_impulses = roundf(num_of_impulses_f);
+        // Save the remainder (in carrier periods) for later use
+        infrared_tim_tx.cycle_remainder = num_of_impulses_f - num_of_impulses;
 
         if(num_of_impulses == 0) {
             if((*size == 0) && (status == FuriHalInfraredTxGetDataStateDone)) {
@@ -521,7 +526,7 @@ static void furi_hal_infrared_tx_fill_buffer(uint8_t buf_num, uint8_t polarity_s
                  */
                 status = FuriHalInfraredTxGetDataStateOk;
             }
-        } else if((num_of_impulses - 1) > 0xFFFF) {
+        } else if((num_of_impulses - 1) > UINT16_MAX) {
             infrared_tim_tx.tx_timing_rest_duration = num_of_impulses - 1;
             infrared_tim_tx.tx_timing_rest_status = status;
             infrared_tim_tx.tx_timing_rest_level = level;
@@ -632,6 +637,7 @@ void furi_hal_infrared_async_tx_start(uint32_t freq, float duty_cycle) {
     infrared_tim_tx.stop_semaphore = furi_semaphore_alloc(1, 0);
     infrared_tim_tx.cycle_duration = 1000000.0 / freq;
     infrared_tim_tx.tx_timing_rest_duration = 0;
+    infrared_tim_tx.cycle_remainder = 0;
 
     furi_hal_infrared_tx_fill_buffer(0, INFRARED_POLARITY_SHIFT);
 
@@ -655,7 +661,7 @@ void furi_hal_infrared_async_tx_start(uint32_t freq, float duty_cycle) {
     const GpioPin* tx_gpio = infrared_tx_pins[infrared_tx_output];
     LL_GPIO_ResetOutputPin(tx_gpio->port, tx_gpio->pin); /* when disable it prevents false pulse */
     furi_hal_gpio_init_ex(
-        tx_gpio, GpioModeAltFunctionPushPull, GpioPullUp, GpioSpeedHigh, GpioAltFn1TIM1);
+        tx_gpio, GpioModeAltFunctionPushPull, GpioPullNo, GpioSpeedHigh, GpioAltFn1TIM1);
 
     FURI_CRITICAL_ENTER();
     LL_TIM_GenerateEvent_UPDATE(INFRARED_DMA_TIMER); /* TIMx_RCR -> Repetition counter */