We generated ADC code for STM32H755 using CubeMx. ADC1 is setup a single channel, one shot conversion. We are using internal Vref at 2.5V. We are reading 0.9V as a test and the DR keeps changing randomly. What are we doing wrong? Thanks!
// adc.c generated by CubeMx
/* ADC1 init function */
void MX_ADC1_Init(void)
{
ADC_MultiModeTypeDef multimode = {0};
ADC_ChannelConfTypeDef sConfig = {0};
/** Common config */
hadc1.Instance = ADC1;
hadc1.Init.ClockPrescaler = ADC_CLOCK_ASYNC_DIV16;
hadc1.Init.Resolution = ADC_RESOLUTION_16B;
hadc1.Init.ScanConvMode = ADC_SCAN_DISABLE;
hadc1.Init.EOCSelection = ADC_EOC_SINGLE_CONV;
hadc1.Init.LowPowerAutoWait = DISABLE;
hadc1.Init.ContinuousConvMode = DISABLE;
hadc1.Init.NbrOfConversion = 1;
hadc1.Init.DiscontinuousConvMode = DISABLE;
hadc1.Init.ExternalTrigConv = ADC_SOFTWARE_START;
hadc1.Init.ExternalTrigConvEdge = ADC_EXTERNALTRIGCONVEDGE_NONE;
hadc1.Init.ConversionDataManagement = ADC_CONVERSIONDATA_DR;
hadc1.Init.Overrun = ADC_OVR_DATA_PRESERVED;
hadc1.Init.LeftBitShift = ADC_LEFTBITSHIFT_NONE;
hadc1.Init.OversamplingMode = DISABLE;
if (HAL_ADC_Init(&hadc1) != HAL_OK)
{
Error_Handler();
}
/** Configure the ADC multi-mode */
multimode.Mode = ADC_MODE_INDEPENDENT;
if (HAL_ADCEx_MultiModeConfigChannel(&hadc1, &multimode) != HAL_OK)
{
Error_Handler();
}
/** Configure Regular Channel */
sConfig.Channel = ADC_CHANNEL_5;
sConfig.Rank = ADC_REGULAR_RANK_1;
sConfig.SamplingTime = ADC_SAMPLETIME_16CYCLES_5;
sConfig.SingleDiff = ADC_SINGLE_ENDED;
sConfig.OffsetNumber = ADC_OFFSET_NONE;
sConfig.Offset = 0;
if (HAL_ADC_ConfigChannel(&hadc1, &sConfig) != HAL_OK)
{
Error_Handler();
}
}
// Application code
// Enable Vref at 2.5V
VREFBUF->CSR = 0x00000001;
while((VREFBUF->CSR & 0x8) == 0) {};
MX_ADC1_Init();
#define A2D_TIMEOUT (2000) // 2 seconds
//----------------------------------------------------------------------------------------------------------------------------------
static Bool bat_ReadA2D( Bool Stop, ADC_HandleTypeDef *Hadc, UInt16 *Value )
{ Bool success = FALSE;
HAL_StatusTypeDef stat;
stat = HAL_ADC_Start( Hadc );
if ( stat != HAL_OK ) { printf( "Start ADC Failed, Err:%d", stat ); return FALSE; }
stat = HAL_ADC_PollForConversion( Hadc, A2D_TIMEOUT );
if ( stat != HAL_OK ) { printf( "ADC Read Failed, Err:%d", stat ); goto StopProcess; }
success = TRUE;
*Value = HAL_ADC_GetValue( Hadc );
if ( !Stop ) return success;
StopProcess:
stat = HAL_ADC_Stop( Hadc );
if ( stat != HAL_OK ) { printf( "ADC Stop Failed, Err:%d", stat ); }
return success;
}
