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
