STM32MP157A M4, the result of ADC_1 always is odd value. (the DR LSB is '1' always.)
Hi,
I'm porting ADC on M4, but some how the converting result is odd value always, seems the DR bit-0 is always '1'.
I tested it by VR, range from 0v to 3.3v, the ADC suppose to convert it from 0 to 255, but I don't know why, I just get odd value back, like 1, 3,5....197,199,201....255. No even number at all.
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H/W configuration:
ADC Input: ANA0
Vref+ = 3.3V
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Here are the ADC configuration...
int SensorAdc_Init(void)
{
ADC_ChannelConfTypeDef channel_cfg;
hSensorAdc.Instance = ADC1;
hSensorAdc.Init.ClockPrescaler = ADC_CLOCK_SYNC_PCLK_DIV2;
hSensorAdc.Init.Resolution = ADC_RESOLUTION_8B;
hSensorAdc.Init.ScanConvMode = ADC_SCAN_DISABLE; /* Sequencer disabled (ADC conversion on only 1 channel: channel set on rank 1) */
hSensorAdc.Init.EOCSelection = ADC_EOC_SINGLE_CONV;
hSensorAdc.Init.LowPowerAutoWait = DISABLE;
hSensorAdc.Init.ContinuousConvMode = DISABLE; /* Continuous mode disabled to have only 1 conversion at each conversion trig */
hSensorAdc.Init.NbrOfConversion = 1; /* Parameter discarded because sequencer is disabled */
hSensorAdc.Init.DiscontinuousConvMode = DISABLE; /* Parameter discarded because sequencer is disabled */
hSensorAdc.Init.NbrOfDiscConversion = 1; /* Parameter discarded because sequencer is disabled */
hSensorAdc.Init.ExternalTrigConv = ADC_SOFTWARE_START; //ADC_EXTERNALTRIG_T2_TRGO; /* Trig of conversion start done by external event */
hSensorAdc.Init.ExternalTrigConvEdge = ADC_EXTERNALTRIGCONVEDGE_NONE; //ADC_EXTERNALTRIGCONVEDGE_RISING; /* Parameter discarded because trig of conversion by software start (no external event) */
hSensorAdc.Init.ConversionDataManagement = ADC_CONVERSIONDATA_DMA_CIRCULAR;
hSensorAdc.Init.Overrun = ADC_OVR_DATA_OVERWRITTEN;
hSensorAdc.Init.OversamplingMode = DISABLE;
if (HAL_ADC_DeInit(&hSensorAdc) != HAL_OK){
/* ADC Deinitialization error */
Error_Handler();
return -1;
}
if (HAL_ADC_Init(&hSensorAdc) != HAL_OK){
/* ADC initialization error */
Error_Handler();
return -1;
}
channel_cfg.Channel = ADC_CHANNEL_0; /* ADC channel selection */
channel_cfg.Rank = ADC_REGULAR_RANK_1; /* ADC group regular rank in which is mapped the selected ADC channel */
channel_cfg.SamplingTime = ADC_SAMPLETIME_810CYCLES_5; /* ADC channel sampling time */
channel_cfg.SingleDiff = ADC_SINGLE_ENDED; /* ADC channel differential mode */
channel_cfg.OffsetNumber = ADC_OFFSET_NONE; /* ADC channel affected to offset number */
channel_cfg.Offset = 0; /* Parameter discarded because offset correction is disabled */
if (HAL_ADC_ConfigChannel(&hSensorAdc, &channel_cfg) != HAL_OK)
{
/* Channel Configuration Error */
Error_Handler();
return -1;
}
if (ret = HAL_ADC_Start_DMA(&hSensorAdc, (uint32_t *)AdcConvData, ADC_CONVERTED_DATA_BUFFER_SIZE) != HAL_OK){/* ADC conversion start error */
Error_Handler();
return -1;
}
return 0;
}
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Please advise .
Many thanks.
FC