Add DMA ring buffer file for UART, Improve calculation of PT1000 resistance

This commit is contained in:
Mario Hüttel 2020-02-05 23:09:23 +01:00
parent 4c7909adac
commit 3ac252db69
5 changed files with 118 additions and 30 deletions

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@ -12,8 +12,11 @@ static float filter_alpha;
static volatile float pt1000_res_raw_lf; static volatile float pt1000_res_raw_lf;
static volatile bool filter_ready; static volatile bool filter_ready;
static volatile enum adc_pt1000_error pt1000_error; static volatile enum adc_pt1000_error pt1000_error;
static volatile uint8_t * volatile dma_flag_ptr = NULL; static volatile uint8_t * volatile streaming_flag_ptr = NULL;
static uint32_t filter_startup_cnt; static uint32_t filter_startup_cnt;
static volatile float adc_pt1000_raw_reading_hf;
static volatile uint16_t dma_sample_buffer[ADC_PT1000_DMA_AVG_SAMPLES];
#define ADC_TO_RES(adc) ((float)(adc) / 4096.0f * 2500.0f) #define ADC_TO_RES(adc) ((float)(adc) / 4096.0f * 2500.0f)
@ -50,6 +53,54 @@ static inline void adc_pt1000_disable_adc()
rcc_manager_disable_clock(&RCC->AHB1ENR, BITMASK_TO_BITNO(ADC_PT1000_PORT_RCC_MASK)); rcc_manager_disable_clock(&RCC->AHB1ENR, BITMASK_TO_BITNO(ADC_PT1000_PORT_RCC_MASK));
} }
/**
* @brief Enable DMA Stream for ADC
*
* DMA2 Stream 0 is used. It will capture @ref ADC_PT1000_DMA_AVG_SAMPLES measurement values,
* delete the two most extreme values
* and calculate the avereage over the remaining values. This ensures, that one time errors are
* not included in the measurement.
*
* After that, the moving average filter is fed with the values.
*
*/
static inline void adc_pt1000_enable_dma_stream()
{
/* Enable peripheral clock for DMA2 */
rcc_manager_enable_clock(&RCC->AHB1ENR, BITMASK_TO_BITNO(RCC_AHB1ENR_DMA2EN));
/* Destination is the DMA sample buffer */
DMA2_Stream0->M0AR = (uint32_t)dma_sample_buffer;
/* Source is the ADC data register */
DMA2_Stream0->PAR = (uint32_t)&ADC1->DR;
/* Transfer size is ADC_PT1000_DMA_AVG_SAMPLES */
DMA2_Stream0->NDTR = ADC_PT1000_DMA_AVG_SAMPLES;
NVIC_EnableIRQ(DMA2_Stream0_IRQn);
/* Enable the stream in Peripheral-to-Memory mode with 16 bit data and a circular destination buffer
* Enable interrupt generation on transfer complete
*
* Todo: Maybe use twice as big of a buffer and also use half-fill interrupt in order to prevent overruns
*/
DMA2_Stream0->CR = DMA_SxCR_PL_1 | DMA_SxCR_MSIZE_0 | DMA_SxCR_PSIZE_0 | DMA_SxCR_MINC |
DMA_SxCR_CIRC | DMA_SxCR_TCIE | DMA_SxCR_EN;
}
static inline void adc_pt1000_disable_dma_stream()
{
/* Disable the stream */
DMA2_Stream0->CR = 0;
/* Disable clock if necessary */
rcc_manager_disable_clock(&RCC->AHB1ENR, BITMASK_TO_BITNO(RCC_AHB1ENR_DMA2EN));
/* Disable interrupt */
NVIC_DisableIRQ(DMA2_Stream0_IRQn);
}
void adc_pt1000_setup_meas() void adc_pt1000_setup_meas()
{ {
rcc_manager_enable_clock(&RCC->APB2ENR, BITMASK_TO_BITNO(RCC_APB2ENR_ADC1EN)); rcc_manager_enable_clock(&RCC->APB2ENR, BITMASK_TO_BITNO(RCC_APB2ENR_ADC1EN));
@ -76,8 +127,8 @@ void adc_pt1000_setup_meas()
/* Set channel as 1st element in sequence */ /* Set channel as 1st element in sequence */
ADC1->SQR3 = (ADC_PT1000_CHANNEL<<0); ADC1->SQR3 = (ADC_PT1000_CHANNEL<<0);
ADC1->CR1 = ADC_CR1_OVRIE | ADC_CR1_AWDEN | ADC_CR1_EOCIE; ADC1->CR1 = ADC_CR1_OVRIE | ADC_CR1_AWDEN | ADC_CR1_AWDIE;
ADC1->CR2 = ADC_CR2_EXTEN_0 | ADC_CR2_EXTSEL_2 | ADC_CR2_EXTSEL_1 | ADC_CR2_ADON; ADC1->CR2 = ADC_CR2_EXTEN_0 | ADC_CR2_EXTSEL_2 | ADC_CR2_EXTSEL_1 | ADC_CR2_ADON | ADC_CR2_DMA | ADC_CR2_DDS;
adc_pt1000_set_moving_average_filter_param(ADC_PT1000_FILTER_WEIGHT); adc_pt1000_set_moving_average_filter_param(ADC_PT1000_FILTER_WEIGHT);
adc_pt1000_set_resistance_calibration(0, 0, false); adc_pt1000_set_resistance_calibration(0, 0, false);
@ -85,7 +136,7 @@ void adc_pt1000_setup_meas()
NVIC_EnableIRQ(ADC_IRQn); NVIC_EnableIRQ(ADC_IRQn);
RCC->AHB1ENR |= RCC_AHB1ENR_DMA2EN; adc_pt1000_enable_dma_stream();
adc_pt1000_setup_sample_frequency_timer(); adc_pt1000_setup_sample_frequency_timer();
} }
@ -170,21 +221,49 @@ void adc_pt1000_disable()
{ {
adc_pt1000_disable_adc(); adc_pt1000_disable_adc();
adc_pt1000_stop_sample_frequency_timer(); adc_pt1000_stop_sample_frequency_timer();
adc_pt1000_disable_dma_stream();
filter_ready = false; filter_ready = false;
pt1000_res_raw_lf = 0.0f; pt1000_res_raw_lf = 0.0f;
if (dma_flag_ptr) { if (streaming_flag_ptr) {
*dma_flag_ptr = -3; *streaming_flag_ptr = -3;
dma_flag_ptr = NULL; streaming_flag_ptr = NULL;
} }
} }
static inline __attribute__((optimize("O3"))) void adc_pt1000_filter(uint16_t adc_value) static inline __attribute__((optimize("O3"))) void adc_pt1000_filter(float adc_prefiltered_value)
{ {
if (!filter_ready && --filter_startup_cnt <= 0) if (!filter_ready && --filter_startup_cnt <= 0)
filter_ready = true; filter_ready = true;
pt1000_res_raw_lf = (1-filter_alpha) * pt1000_res_raw_lf + filter_alpha * ADC_TO_RES((float)adc_value); pt1000_res_raw_lf = (1.0f-filter_alpha) * pt1000_res_raw_lf + filter_alpha * ADC_TO_RES(adc_prefiltered_value);
}
static inline __attribute__((optimize("O3"))) float adc_pt1000_dma_avg_pre_filter()
{
int i;
uint32_t sum = 0;
uint16_t max_val = 0U;
uint16_t min_val = 65535U;
uint16_t sample;
for (i = 0; i < ADC_PT1000_DMA_AVG_SAMPLES; i++) {
sample = dma_sample_buffer[i];
/* Update min and max trackers */
max_val = (sample > max_val ? sample : max_val);
min_val = (sample < min_val ? sample : min_val);
/* Sum up all values (for average) */
sum += sample;
}
/* Delete max and min vals from sum */
sum = sum - (uint32_t)max_val - (uint32_t)min_val;
/* Divide to get average and return */
return (float)sum / (ADC_PT1000_DMA_AVG_SAMPLES-2);
} }
void ADC_IRQHandler(void) void ADC_IRQHandler(void)
@ -192,19 +271,15 @@ void ADC_IRQHandler(void)
uint32_t adc1_sr; uint32_t adc1_sr;
adc1_sr = ADC1->SR; adc1_sr = ADC1->SR;
if (ADC1->SR & ADC_SR_EOC) {
ADC1->SR &= ~ADC_SR_EOC;
adc_pt1000_filter(ADC1->DR);
}
if (adc1_sr & ADC_SR_OVR) { if (adc1_sr & ADC_SR_OVR) {
ADC1->SR &= ~ADC_SR_OVR; ADC1->SR &= ~ADC_SR_OVR;
pt1000_error |= ADC_PT1000_OVERFLOW; pt1000_error |= ADC_PT1000_OVERFLOW;
/* Disable ADC in case of overrrun*/ /* Disable ADC in case of overrrun*/
adc_pt1000_disable(); adc_pt1000_disable();
if (dma_flag_ptr) { if (streaming_flag_ptr) {
*dma_flag_ptr = -1; *streaming_flag_ptr = -1;
dma_flag_ptr = NULL; streaming_flag_ptr = NULL;
} }
} }
@ -217,18 +292,23 @@ void ADC_IRQHandler(void)
void DMA2_Stream0_IRQHandler() void DMA2_Stream0_IRQHandler()
{ {
uint32_t lisr; uint32_t lisr;
float adc_val;
lisr = DMA2->LISR; lisr = DMA2->LISR;
DMA2->LIFCR = lisr; DMA2->LIFCR = lisr;
if (lisr & DMA_LISR_TCIF0 && dma_flag_ptr) { if (lisr & DMA_LISR_TCIF0) {
*dma_flag_ptr = 1; /* Samples Transfered */
dma_flag_ptr = NULL; adc_val = adc_pt1000_dma_avg_pre_filter();
adc_pt1000_raw_reading_hf = adc_val;
/* Call moving average filter */
adc_pt1000_filter(adc_val);
} }
if (lisr & DMA_LISR_TEIF0 && dma_flag_ptr) { if (lisr & DMA_LISR_TEIF0) {
*dma_flag_ptr = -2; /* Wait for watchdog to kick in */
dma_flag_ptr = NULL; while(1);
} }
} }

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@ -12,30 +12,32 @@
/** /**
* @brief ADC channel number of PT1000 sensor input * @brief ADC channel number of PT1000 sensor input
*/ */
#define ADC_PT1000_CHANNEL 2 #define ADC_PT1000_CHANNEL 2U
#define ADC_PT1000_PORT GPIOA #define ADC_PT1000_PORT GPIOA
#define ADC_PT1000_PORT_RCC_MASK RCC_AHB1ENR_GPIOAEN #define ADC_PT1000_PORT_RCC_MASK RCC_AHB1ENR_GPIOAEN
#define ADC_PT1000_PIN 2 #define ADC_PT1000_PIN 2U
#define ADC_FILTER_STARTUP_CYCLES 800 #define ADC_FILTER_STARTUP_CYCLES 800U
#define ADC_PT1000_SAMPLE_CNT_DELAY 2000 #define ADC_PT1000_SAMPLE_CNT_DELAY 1000U
#define ADC_PT1000_DMA_AVG_SAMPLES 6U
/** /**
* @brief Lower value for valid input range for PT1000 measurement * @brief Lower value for valid input range for PT1000 measurement
* *
* If the input of the PT1000 sensor is below this value, an error is thrown. This is used to disable the temperature control loop * If the input of the PT1000 sensor is below this value, an error is thrown. This is used to disable the temperature control loop
*/ */
#define ADC_PT1000_LOWER_WATCHDOG 100 #define ADC_PT1000_LOWER_WATCHDOG 200U
/** /**
* @brief Upper value for valid input range for PT1000 measurement * @brief Upper value for valid input range for PT1000 measurement
* *
* If the input of the PT1000 sensor is above this value, an error is thrown. This is used to disable the temperature control loop * If the input of the PT1000 sensor is above this value, an error is thrown. This is used to disable the temperature control loop
*/ */
#define ADC_PT1000_UPPER_WATCHDOG 4000 #define ADC_PT1000_UPPER_WATCHDOG 4000U
enum adc_pt1000_error {ADC_PT1000_NO_ERR= 0, ADC_PT1000_WATCHDOG_ERROR=(1UL<<0), ADC_PT1000_OVERFLOW=(1UL<<1)}; enum adc_pt1000_error {ADC_PT1000_NO_ERR= 0, ADC_PT1000_WATCHDOG_ERROR=(1UL<<0), ADC_PT1000_OVERFLOW=(1UL<<1)};

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@ -0,0 +1,4 @@
#ifndef __DMA_RING_BUFFER_H__
#define __DMA_RING_BUFFER_H__
#endif /* __DMA_RING_BUFFER_H__ */

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@ -20,8 +20,8 @@ static void setup_nvic_priorities()
NVIC_SetPriorityGrouping(2); NVIC_SetPriorityGrouping(2);
/* Setup Priorities */ /* Setup Priorities */
NVIC_SetPriority(ADC_IRQn, 1); NVIC_SetPriority(ADC_IRQn, 2);
NVIC_SetPriority(DMA2_Stream0_IRQn, 2); NVIC_SetPriority(DMA2_Stream0_IRQn, 1);
} }
static float pt1000_value; static float pt1000_value;

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@ -0,0 +1,2 @@
#include <uart/dma-ring-buffer.h>