Add optional conversion complete callback to AdcHandle::Start()

Author: TheSlowGrowth

src/per/adc.cpp

@@ -147,6 +147,8 @@ struct dsy_adc
     ADC_HandleTypeDef hadc1;
     DMA_HandleTypeDef hdma_adc1;
     bool              mux_used; // flag set when mux is configured
+    AdcHandle::ConversionCompleteCallbackFunctionPtr complete_callback;
+    void*                                            complete_callback_context;
 };
 
 // Static Functions
@@ -350,6 +352,10 @@ void AdcHandle::Init(AdcChannelConfig* cfg,
     {
         adc.hadc1.Init.OversamplingMode = DISABLE;
     }
+
+    adc.complete_callback         = nullptr;
+    adc.complete_callback_context = nullptr;
+
     // Init ADC
     if(HAL_ADC_Init(&adc.hadc1) != HAL_OK)
     {
@@ -421,8 +427,12 @@ void AdcHandle::Init(AdcChannelConfig* cfg,
     }
 }
 
-void AdcHandle::Start()
+void AdcHandle::Start(ConversionCompleteCallbackFunctionPtr callback,
+                      void*                                 callback_context)
 {
+    adc.complete_callback         = callback;
+    adc.complete_callback_context = callback_context;
+
     HAL_ADCEx_Calibration_Start(
         &adc.hadc1, ADC_CALIB_OFFSET_LINEARITY, ADC_SINGLE_ENDED);
     HAL_ADC_Start_DMA(&adc.hadc1, (uint32_t*)adc.dma_buffer, adc.channels);
@@ -580,9 +590,17 @@ extern "C"
 
     void HAL_ADC_ConvCpltCallback(ADC_HandleTypeDef* hadc)
     {
-        if(hadc->Instance == ADC1 && adc.mux_used)
+        if(hadc->Instance == ADC1)
         {
-            adc_internal_callback();
+            if(adc.mux_used)
+            {
+                adc_internal_callback();
+            }
+
+            if(adc.complete_callback)
+            {
+                adc.complete_callback(adc.complete_callback_context);
+            }
         }
     }
 

src/per/adc.h

@@ -106,6 +106,9 @@ class AdcHandle
         OVS_LAST, /**< & */
     };
 
+    /** A callback to be executed after a conversion is completed. */
+    typedef void (*ConversionCompleteCallbackFunctionPtr)(void *context);
+
     AdcHandle() {}
     ~AdcHandle() {}
     /** 
@@ -117,8 +120,15 @@ class AdcHandle
     void
     Init(AdcChannelConfig *cfg, size_t num_channels, OverSampling ovs = OVS_32);
 
-    /** Starts reading from the ADC */
-    void Start();
+    /** Starts reading from the ADC.
+    \param callback an optional callback to be called when a conversion is
+                    complete on all ADC channels. Note that if a mux is used on
+                    a ADC channel, only one of the muxed inputs will have a new
+                    value when this callback is called.
+    \param callback_context a context pointer that will be handed to the callback
+     */
+    void Start(ConversionCompleteCallbackFunctionPtr callback = nullptr,
+               void *callback_context                         = nullptr);
 
     /** Stops reading from the ADC */
     void Stop();