Merge pull request #3268 from shellixyz/adc_averaging_stm32f3

ADC samples averaging with added STM32F30x support
iNavFlight · May 31, 2018 · 1b0d888 · 1b0d888
2 parents 83bb1b8 + 15955b5
commit 1b0d888
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Showing 6 changed files with 39 additions and 6 deletions.
diff --git a/src/main/drivers/adc.c b/src/main/drivers/adc.c
@@ -51,9 +51,13 @@
 
 #ifdef USE_ADC
 
+#if defined(USE_ADC_AVERAGING)
+static uint8_t activeChannelCount[ADCDEV_COUNT] = {0};
+#endif
+
 static int adcFunctionMap[ADC_FUNCTION_COUNT];
 adc_config_t adcConfig[ADC_CHN_COUNT];  // index 0 is dummy for ADC_CHN_NONE
-volatile uint16_t adcValues[ADCDEV_COUNT][ADC_CHN_COUNT];
+volatile uint16_t adcValues[ADCDEV_COUNT][ADC_CHN_COUNT * ADC_AVERAGE_N_SAMPLES];
 
 uint8_t adcChannelByTag(ioTag_t ioTag)
 {
@@ -82,7 +86,15 @@ uint16_t adcGetChannel(uint8_t function)
         return 0;
 
     if (adcConfig[channel].adcDevice != ADCINVALID && adcConfig[channel].enabled) {
+#if !defined(USE_ADC_AVERAGING)
         return adcValues[adcConfig[channel].adcDevice][adcConfig[channel].dmaIndex];
+#else
+        uint32_t acc = 0;
+        for (int i = 0; i < ADC_AVERAGE_N_SAMPLES; i++) {
+            acc += adcValues[adcConfig[channel].adcDevice][adcConfig[channel].dmaIndex + i * activeChannelCount[adcConfig[channel].adcDevice]];
+        }
+        return acc / ADC_AVERAGE_N_SAMPLES;
+#endif
     } else {
         return 0;
     }
@@ -128,6 +140,9 @@ void adcInit(drv_adc_config_t *init)
         adcConfig[ADC_CHN_1].adcDevice = adcDeviceByInstance(ADC_CHANNEL_1_INSTANCE);
         if (adcConfig[ADC_CHN_1].adcDevice != ADCINVALID) {
             adcConfig[ADC_CHN_1].tag = IO_TAG(ADC_CHANNEL_1_PIN);
+#if defined(USE_ADC_AVERAGING)
+            activeChannelCount[adcConfig[ADC_CHN_1].adcDevice] += 1;
+#endif
         }
     }
 #else
@@ -139,6 +154,9 @@ void adcInit(drv_adc_config_t *init)
         adcConfig[ADC_CHN_2].adcDevice = adcDeviceByInstance(ADC_CHANNEL_2_INSTANCE);
         if (adcConfig[ADC_CHN_2].adcDevice != ADCINVALID) {
             adcConfig[ADC_CHN_2].tag = IO_TAG(ADC_CHANNEL_2_PIN);
+#if defined(USE_ADC_AVERAGING)
+            activeChannelCount[adcConfig[ADC_CHN_2].adcDevice] += 1;
+#endif
         }
     }
 #else
@@ -150,6 +168,9 @@ void adcInit(drv_adc_config_t *init)
         adcConfig[ADC_CHN_3].adcDevice = adcDeviceByInstance(ADC_CHANNEL_3_INSTANCE);
         if (adcConfig[ADC_CHN_3].adcDevice != ADCINVALID) {
             adcConfig[ADC_CHN_3].tag = IO_TAG(ADC_CHANNEL_3_PIN);
+#if defined(USE_ADC_AVERAGING)
+            activeChannelCount[adcConfig[ADC_CHN_3].adcDevice] += 1;
+#endif
         }
     }
 #else
@@ -161,6 +182,9 @@ void adcInit(drv_adc_config_t *init)
         adcConfig[ADC_CHN_4].adcDevice = adcDeviceByInstance(ADC_CHANNEL_4_INSTANCE);
         if (adcConfig[ADC_CHN_4].adcDevice != ADCINVALID) {
             adcConfig[ADC_CHN_4].tag = IO_TAG(ADC_CHANNEL_4_PIN);
+#if defined(USE_ADC_AVERAGING)
+            activeChannelCount[adcConfig[ADC_CHN_4].adcDevice] += 1;
+#endif
         }
     }
 #else

diff --git a/src/main/drivers/adc.h b/src/main/drivers/adc.h
@@ -45,3 +45,7 @@ void adcInit(drv_adc_config_t *init);
 uint16_t adcGetChannel(uint8_t channel);
 bool adcIsFunctionAssigned(uint8_t function);
 int adcGetFunctionChannelAllocation(uint8_t function);
+
+#if !defined(USE_ADC_AVERAGING)
+#define ADC_AVERAGE_N_SAMPLES 1
+#endif
diff --git a/src/main/drivers/adc_impl.h b/src/main/drivers/adc_impl.h
@@ -78,7 +78,7 @@ typedef struct adc_config_s {
 
 extern const adcTagMap_t adcTagMap[ADC_TAG_MAP_COUNT];
 extern adc_config_t adcConfig[ADC_CHN_COUNT];
-extern volatile uint16_t adcValues[ADCDEV_COUNT][ADC_CHN_COUNT];
+extern volatile uint16_t adcValues[ADCDEV_COUNT][ADC_CHN_COUNT * ADC_AVERAGE_N_SAMPLES];
 
 void adcHardwareInit(drv_adc_config_t *init);
 ADCDevice adcDeviceByInstance(ADC_TypeDef *instance);

diff --git a/src/main/drivers/adc_stm32f30x.c b/src/main/drivers/adc_stm32f30x.c
@@ -107,9 +107,9 @@ static void adcInstanceInit(ADCDevice adcDevice)
     DMA_InitStructure.DMA_PeripheralBaseAddr = (uint32_t)&adc->ADCx->DR;
     DMA_InitStructure.DMA_MemoryBaseAddr = (uint32_t)adcValues[adcDevice];
     DMA_InitStructure.DMA_DIR = DMA_DIR_PeripheralSRC;
-    DMA_InitStructure.DMA_BufferSize = adc->usedChannelCount;
+    DMA_InitStructure.DMA_BufferSize = adc->usedChannelCount * ADC_AVERAGE_N_SAMPLES;
     DMA_InitStructure.DMA_PeripheralInc = DMA_PeripheralInc_Disable;
-    DMA_InitStructure.DMA_MemoryInc = adc->usedChannelCount > 1 ? DMA_MemoryInc_Enable : DMA_MemoryInc_Disable;
+    DMA_InitStructure.DMA_MemoryInc = ((adc->usedChannelCount > 1) || (ADC_AVERAGE_N_SAMPLES > 1)) ? DMA_MemoryInc_Enable : DMA_MemoryInc_Disable;
     DMA_InitStructure.DMA_PeripheralDataSize = DMA_PeripheralDataSize_HalfWord;
     DMA_InitStructure.DMA_MemoryDataSize = DMA_MemoryDataSize_HalfWord;
     DMA_InitStructure.DMA_Mode = DMA_Mode_Circular;

diff --git a/src/main/drivers/adc_stm32f4xx.c b/src/main/drivers/adc_stm32f4xx.c
@@ -99,9 +99,9 @@ static void adcInstanceInit(ADCDevice adcDevice)
     DMA_InitStructure.DMA_Channel = adc->channel;
     DMA_InitStructure.DMA_Memory0BaseAddr = (uint32_t)adcValues[adcDevice];
     DMA_InitStructure.DMA_DIR = DMA_DIR_PeripheralToMemory;
-    DMA_InitStructure.DMA_BufferSize = adc->usedChannelCount;
+    DMA_InitStructure.DMA_BufferSize = adc->usedChannelCount * ADC_AVERAGE_N_SAMPLES;
     DMA_InitStructure.DMA_PeripheralInc = DMA_PeripheralInc_Disable;
-    DMA_InitStructure.DMA_MemoryInc = adc->usedChannelCount > 1 ? DMA_MemoryInc_Enable : DMA_MemoryInc_Disable;
+    DMA_InitStructure.DMA_MemoryInc = ((adc->usedChannelCount > 1) || (ADC_AVERAGE_N_SAMPLES > 1)) ? DMA_MemoryInc_Enable : DMA_MemoryInc_Disable;
     DMA_InitStructure.DMA_PeripheralDataSize = DMA_PeripheralDataSize_HalfWord;
     DMA_InitStructure.DMA_MemoryDataSize = DMA_MemoryDataSize_HalfWord;
     DMA_InitStructure.DMA_Mode = DMA_Mode_Circular;

diff --git a/src/main/target/common.h b/src/main/target/common.h
@@ -35,6 +35,11 @@
 #define USE_UNDERCLOCK
 #endif
 
+#if defined(STM32F3) || defined(STM32F4)
+#define USE_ADC_AVERAGING
+#define ADC_AVERAGE_N_SAMPLES 20
+#endif
+
 #define USE_64BIT_TIME
 #define USE_BLACKBOX
 #define USE_GPS