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STM32L4 ADC Internal Channel : correct sampling time #6399

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Merged
merged 1 commit into from
Mar 22, 2018
Merged

STM32L4 ADC Internal Channel : correct sampling time #6399

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15 changes: 9 additions & 6 deletions targets/TARGET_STM/TARGET_STM32L4/analogin_device.c
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Original file line number Diff line number Diff line change
Expand Up @@ -105,9 +105,16 @@ uint16_t adc_read(analogin_t *obj)
ADC_ChannelConfTypeDef sConfig = {0};

// Configure ADC channel
sConfig.Rank = ADC_REGULAR_RANK_1;
sConfig.SamplingTime = ADC_SAMPLETIME_47CYCLES_5; // default value (1.5 us for 80MHz clock)
sConfig.SingleDiff = ADC_SINGLE_ENDED;
sConfig.OffsetNumber = ADC_OFFSET_NONE;
sConfig.Offset = 0;

switch (obj->channel) {
case 0:
sConfig.Channel = ADC_CHANNEL_VREFINT;
sConfig.SamplingTime = ADC_SAMPLETIME_247CYCLES_5; // Minimum ADC sampling time when reading the internal reference voltage is 4us
break;
case 1:
sConfig.Channel = ADC_CHANNEL_1;
Expand Down Expand Up @@ -159,20 +166,16 @@ uint16_t adc_read(analogin_t *obj)
break;
case 17:
sConfig.Channel = ADC_CHANNEL_TEMPSENSOR;
sConfig.SamplingTime = ADC_SAMPLETIME_247CYCLES_5; // Minimum ADC sampling time when reading the temperature is 5us
break;
case 18:
sConfig.Channel = ADC_CHANNEL_VBAT;
sConfig.SamplingTime = ADC_SAMPLETIME_640CYCLES_5; // Minimum ADC sampling time when reading the VBAT is 12us
break;
default:
return 0;
}

sConfig.Rank = ADC_REGULAR_RANK_1;
sConfig.SamplingTime = ADC_SAMPLETIME_47CYCLES_5;
sConfig.SingleDiff = ADC_SINGLE_ENDED;
sConfig.OffsetNumber = ADC_OFFSET_NONE;
sConfig.Offset = 0;

HAL_ADC_ConfigChannel(&obj->handle, &sConfig);

HAL_ADC_Start(&obj->handle); // Start conversion
Expand Down