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adc.c
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Sun, Apr 28, 18:39

adc.c
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#include "adc.h"
#include "../lib/basic_filter.h"
#include "../lib/utils.h"
volatile uint16_t adc_currentValuesBuffer[ADC_BUFFER_SIZE];
bfilt_BasicFilter adc_currentFilter;
float32_t adc_currentSensOffset = 0.0f;
void adc_DmaInit(void);
/**
* @brief Initialize the ADC converter (2 analog inputs + current sense).
*/
void adc_Init(void)
{
ADC_InitTypeDef ADC_InitStructure;
ADC_CommonInitTypeDef ADC_CommonInitStructure;
GPIO_InitTypeDef GPIO_InitStructure;
adc_DmaInit();
// Periph clock enable
RCC_APB2PeriphClockCmd(RCC_APB2Periph_ADC1|RCC_APB2Periph_ADC2, ENABLE);
RCC_APB2PeriphClockCmd(RCC_APB2Periph_ADC3,ENABLE);
// GPIO configuration
GPIO_InitStructure.GPIO_Pin = ADC_HALL_PIN;
GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AN;
GPIO_InitStructure.GPIO_PuPd = GPIO_PuPd_NOPULL;
GPIO_Init(ADC_HALL_PORT, &GPIO_InitStructure);
GPIO_InitStructure.GPIO_Pin = ADC_ANIN1_PIN;
GPIO_Init(ADC_ANIN1_PORT, &GPIO_InitStructure);
GPIO_InitStructure.GPIO_Pin = ADC_ANIN2_PIN;
GPIO_Init(ADC_ANIN2_PORT, &GPIO_InitStructure);
GPIO_InitStructure.GPIO_Pin = ADC_ANIN3_PIN;
GPIO_Init(ADC_ANIN3_PORT, &GPIO_InitStructure);
GPIO_InitStructure.GPIO_Pin = ADC_ANIN4_PIN;
GPIO_Init(ADC_ANIN4_PORT, &GPIO_InitStructure);
GPIO_InitStructure.GPIO_Pin = ADC_CURRENT_SENSE_PIN;
GPIO_Init(ADC_CURRENT_SENSE_PORT, &GPIO_InitStructure);
// ADC Common configuration
ADC_DeInit();
ADC_CommonInitStructure.ADC_Mode = ADC_Mode_Independent;
ADC_CommonInitStructure.ADC_TwoSamplingDelay = ADC_TwoSamplingDelay_5Cycles; // Useless here (only used in dual or triple interleaved modes).
ADC_CommonInitStructure.ADC_DMAAccessMode = ADC_DMAAccessMode_Disabled;
ADC_CommonInitStructure.ADC_Prescaler = ADC_Prescaler_Div4;
ADC_CommonInit(&ADC_CommonInitStructure);
// ADC 1 configuration for general purpose.
ADC_InitStructure.ADC_Resolution = ADC_Resolution_12b;
ADC_InitStructure.ADC_ScanConvMode = DISABLE;
ADC_InitStructure.ADC_ContinuousConvMode = DISABLE;
ADC_InitStructure.ADC_ExternalTrigConvEdge = ADC_ExternalTrigConvEdge_None;
ADC_InitStructure.ADC_ExternalTrigConv = 0;
ADC_InitStructure.ADC_DataAlign = ADC_DataAlign_Right;
ADC_InitStructure.ADC_NbrOfConversion = 1;
ADC_Init(ADC1, &ADC_InitStructure);
ADC_RegularChannelConfig(ADC1, ADC_HALL_CHANNEL, 1, ADC_SampleTime_56Cycles);
ADC_Cmd(ADC1, ENABLE);
ADC_SoftwareStartConv(ADC1);
// ADC 3 configuration for motor current sensing.
// Synchronous sampling with the PWM replaced by a high-frequency sampling at ~300kHz (over-sampling), because of the commutation noise of the current measuring amplifier at ~120kHz.
ADC_InitStructure.ADC_ContinuousConvMode = ENABLE;
ADC_Init(ADC3, &ADC_InitStructure);
ADC_RegularChannelConfig(ADC3, ADC_CURRENT_SENSE_CHANNEL, 1, ADC_SampleTime_28Cycles);
ADC_DMARequestAfterLastTransferCmd(ADC3, ENABLE);
ADC_DMACmd(ADC3, ENABLE);
ADC_Cmd(ADC3, ENABLE);
ADC_SoftwareStartConv(ADC3);
// Setup the filter of the ADC current samples over time.
bfilt_Init(&adc_currentFilter, 0.05f, 0.0f);
}
/**
* @brief Setup the DMA that copies the current ADC samples to the RAM.
*/
void adc_DmaInit(void)
{
DMA_InitTypeDef DMA_InitStructure;
RCC_AHB1PeriphClockCmd(RCC_AHB1Periph_DMA2, ENABLE);
DMA_InitStructure.DMA_Memory0BaseAddr = (uint32_t)&adc_currentValuesBuffer;
DMA_InitStructure.DMA_DIR = DMA_DIR_PeripheralToMemory;
DMA_InitStructure.DMA_BufferSize = ADC_BUFFER_SIZE;
DMA_InitStructure.DMA_PeripheralInc = DMA_PeripheralInc_Disable;
DMA_InitStructure.DMA_MemoryInc = DMA_MemoryInc_Enable;
DMA_InitStructure.DMA_PeripheralDataSize = DMA_PeripheralDataSize_HalfWord;
DMA_InitStructure.DMA_MemoryDataSize = DMA_MemoryDataSize_HalfWord;
DMA_InitStructure.DMA_Mode = DMA_Mode_Circular;
DMA_InitStructure.DMA_Priority = DMA_Priority_High;
DMA_InitStructure.DMA_FIFOMode = DMA_FIFOMode_Enable;
DMA_InitStructure.DMA_FIFOThreshold = DMA_FIFOThreshold_HalfFull;
DMA_InitStructure.DMA_MemoryBurst = DMA_MemoryBurst_Single;
DMA_InitStructure.DMA_PeripheralBurst = DMA_PeripheralBurst_Single;
DMA_InitStructure.DMA_Channel = DMA_Channel_2;
DMA_InitStructure.DMA_PeripheralBaseAddr = (uint32_t)&ADC3->DR;
DMA_Init(DMA2_Stream1, &DMA_InitStructure);
DMA_Cmd(DMA2_Stream1, ENABLE);
}
/**
* @brief Compute the current sense offset.
* @note Run before enabling current regulation.
*/
void adc_CalibrateCurrentSens(void)
{
float32_t offset = 0.0f;
int32_t i=0;
for(i=0; i<ADC_CALIB_N_SAMPLES; i++)
{
offset += adc_GetCurrent() / (float32_t)ADC_CALIB_N_SAMPLES;
utils_DelayUs(400);
}
adc_currentSensOffset = offset;
}
/**
* @brief Compute the current sense offset.
* @retval The measured current in [mA].
*/
float32_t adc_GetCurrent(void)
{
int32_t motorCurrentSum;
float32_t motorCurrentMean;
int32_t i;
// Compute the average of all the ADC values in the buffer.
motorCurrentSum = 0; // [ADC raw value].
for(i=0; i<ADC_BUFFER_SIZE; i++)
motorCurrentSum += (int32_t)(adc_currentValuesBuffer[i]);
motorCurrentMean = (float32_t)motorCurrentSum / (float32_t)ADC_BUFFER_SIZE;
// Convert from ADC increments to a current in [A].
motorCurrentMean *= ADC_CURRENT_SCALE;
// Add the offset obtained during the sense resistor calibration.
motorCurrentMean -= (float32_t) adc_currentSensOffset;
// Use low-pass filtering to reduce the noise.
bfilt_Step(&adc_currentFilter, motorCurrentMean);
//return motorCurrentMean;
return adc_currentFilter.filteredValue;
}
/**
* @brief Start the ADC conversion of the selected channel.
* @param channel: the ADC channel to acquire.
*/
void adc_StartConversion(AdcChannel channel)
{
ADC_Cmd(ADC1, DISABLE);
ADC_RegularChannelConfig(ADC1, channel, 1, ADC_SampleTime_56Cycles);
ADC_Cmd(ADC1, ENABLE);
utils_DelayUs(1);
ADC_SoftwareStartConv(ADC1);
}
/**
* @brief Gets the ADC conversion status of the selected channel.
* @retval 1 if the conversion is finished, 0 otherwise.
*/
bool adc_ConversionIsFinished(void)
{
return (ADC1->SR & ADC_SR_EOC) != 0;
}
/**
* @brief Gets the voltage measured by the selected ADC channel.
* @return the measured voltage [V].
* @note make sure that the conversion is finished before calling.
*/
float32_t adc_GetConversionResult(void)
{
float32_t adcRawVal, voltage;
adcRawVal = (float32_t)ADC1->DR;
voltage = (adcRawVal / ADC_MAX) * ADC_REF_VOLTAGE;
return voltage;
}
/**
* @brief Gets the voltage measured by the selected ADC channel.
* @param channel: the channel of the ADC.
* @return the measured voltage [V].
*/
float32_t adc_GetChannelVoltage(AdcChannel channel)
{
int32_t conversionTime = 0;
adc_StartConversion(channel);
while(!adc_ConversionIsFinished())
{
if(conversionTime < ADC_MAX_CONVERSION_TIME)
conversionTime++;
else
break;
}
return adc_GetConversionResult();
}

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