Adheres to the STM32F429 reference manual (RM0090) Section 10.3.17 DMA stream configuration procedure.

Before write access is permitted to numerous DMA registers, need to make sure that DMA is disabled for the stream. Disabling the stream is not instantaneous, and needs to be waited for (previous transmissions need to be finished first).

Added return values to numerous functions to signal a failure.

radio/src/hal/adc_driver.cpp

@@ -67,30 +67,49 @@ uint16_t adcValues[NUM_ANALOGS] __DMA;
 uint16_t rtcBatteryVoltage;
 #endif
 
-void adcInit(const etx_hal_adc_driver_t* driver)
+bool adcInit(const etx_hal_adc_driver_t* driver)
 {
   etx_hal_adc_driver = driver;
   if (etx_hal_adc_driver && etx_hal_adc_driver->init)
-    etx_hal_adc_driver->init();
+  {
+    if(!etx_hal_adc_driver->init())
+        return false;
+
+    return true;
+  }
+  return false;
 }
 
-static void adcSingleRead()
+static bool adcSingleRead()
 {
-  if (!etx_hal_adc_driver) return;
+  if (!etx_hal_adc_driver)
+      return false;
 
   if (etx_hal_adc_driver->start_conversion)
-    etx_hal_adc_driver->start_conversion();
+  {
+    if (!etx_hal_adc_driver->start_conversion())
+        return false;
+  }
+  else
+      return false;
 
   if (etx_hal_adc_driver->wait_completion)
+  {
     etx_hal_adc_driver->wait_completion();
+  }
+  else
+      return false;
+
+  return true;
 }
 
-void adcRead()
+bool adcRead()
 {
   uint16_t temp[NUM_ANALOGS] = { 0 };
 
   for (int i=0; i<4; i++) {
-    adcSingleRead();
+    if (!adcSingleRead())
+        return false;
     for (uint8_t x=FIRST_ANALOG_ADC; x<NUM_ANALOGS; x++) {
       uint16_t val = adcValues[x];
 #if defined(JITTER_MEASURE)
@@ -111,6 +130,7 @@ void adcRead()
     sticksPwmRead(adcValues);
   }
 #endif
+  return true;
 }
 
 #if defined(PCBX10)