Fixed ADC output jumping problem

Author: richardclli

radio/src/boards/generic_stm32/analog_inputs.cpp

@@ -70,9 +70,6 @@ static bool adc_start_read()
   if (n_ADC_spi > 0) {
     success = success && ads79xx_adc_start_read(&_ADC_spi[0], _ADC_inputs);
   }
-#endif
-#if defined(FLYSKY_GIMBAL)
-  flysky_gimbal_start_read();
 #endif
   return success;
 }
@@ -85,9 +82,6 @@ static void adc_wait_completion()
   if (n_ADC_spi > 0) ads79xx_adc_wait_completion(&_ADC_spi[0], _ADC_inputs);
 #endif
   stm32_hal_adc_wait_completion(_ADC_adc, n_ADC, _ADC_inputs, n_inputs);
-#if defined(FLYSKY_GIMBAL)
-  flysky_gimbal_wait_completion();
-#endif
 }
 
 const etx_hal_adc_driver_t _adc_driver = {

radio/src/targets/common/arm/stm32/flysky_gimbal_driver.cpp

@@ -72,6 +72,9 @@ static uint8_t _fs_gimbal_version = GIMBAL_V1;
 static uint8_t _fs_gimbal_mode = V1_MODE;
 static uint8_t _fs_gimbal_mode_cmd = V1_MODE;
 static bool _fs_gimbal_read_finished = true;
+static uint32_t _fs_lastReadTick = 0;
+static uint32_t _fs_readTick;
+static uint32_t _fs_sync_period = 0;
 
 static int _fs_get_byte(uint8_t* data)
 {
@@ -210,7 +213,7 @@ static void flysky_gimbal_loop(void*)
             if (majorVersion == 2 && minorVersion >= 1) {
               _fs_gimbal_version = GIMBAL_V2;
               // Enable sync mode
-              _fs_cmd_set_mode(SYNC_1000Hz);
+              _fs_cmd_set_mode(SYNC_RESAMPLING);
             }
           } else if (HallProtocol.hallID.hall_Id.packetID == FLYSKY_PACKET_MODE_ID) {
             _fs_gimbal_mode = _fs_gimbal_mode_cmd;
@@ -265,6 +268,11 @@ void flysky_gimbal_start_read()
   if(_fs_sync_enabled()) {
     if (_fs_gimbal_read_finished) {
       _fs_gimbal_read_finished = false;
+      _fs_lastReadTick = _fs_readTick;
+      _fs_readTick = timersGetUsTick();
+      if (_fs_lastReadTick != 0) {
+        _fs_sync_period = _fs_readTick - _fs_lastReadTick;
+      }
       _fs_cmd_start_read();
     }    
   }

radio/src/targets/common/arm/stm32/flysky_gimbal_driver.h

@@ -133,8 +133,8 @@ enum GIMBAL_VERSION {
 
 enum V2_GIMBAL_MODE {
   V1_MODE = 0,
-  SYNC_400Hz = 1,
-  SYNC_1000Hz = 2
+  SYNC_SAMPLING = 1,   // Can serve sampling frequency < 400Hz
+  SYNC_RESAMPLING = 2  // Can serve sampling frequency up to 1000Hz
 };
 
 extern signed short hall_raw_values[FLYSKY_HALL_CHANNEL_COUNT];

radio/src/tasks/mixer_task.cpp

@@ -33,6 +33,10 @@
 #include "hal/gpio.h"
 #endif
 
+#if defined(FLYSKY_GIMBAL)
+  #include "flysky_gimbal_driver.h"
+#endif
+
 RTOS_TASK_HANDLE mixerTaskId;
 RTOS_DEFINE_STACK(mixerTaskId, mixerStack, MIXER_STACK_SIZE);
 
@@ -250,6 +254,14 @@ void doMixerCalculations()
   getADC();
   DEBUG_TIMER_STOP(debugTimerGetAdc);
 
+ // Need to put all in a group to ensure DMA transfer will not affect ADC sampling
+#if defined(FLYSKY_GIMBAL)
+  flysky_gimbal_start_read();
+#endif
+#if defined(FLYSKY_GIMBAL)
+  flysky_gimbal_wait_completion();
+#endif
+
   DEBUG_TIMER_START(debugTimerGetSwitches);
   getSwitchesPosition(!s_mixer_first_run_done);
   DEBUG_TIMER_STOP(debugTimerGetSwitches);