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STM32F411: simplify analog readings 

We don't need an interrupt for the DMA.
Simply clear and set the DMA-bit for the ADC is sufficient.
This commit is contained in:
Nico Tonnhofer 2017-01-20 19:21:02 +01:00
parent aeb98b557b
commit 767c4a6911
1 changed files with 6 additions and 24 deletions
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30
analog-stm32.c
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@ -9,6 +9,7 @@
#include "cmsis-stm32f4xx.h" #include "cmsis-stm32f4xx.h"
#include "arduino.h" #include "arduino.h"
#include "pinio.h"
#include "delay.h" #include "delay.h"
#include "temp.h" #include "temp.h"
#include <string.h> #include <string.h>
@ -48,9 +49,9 @@ void init_analog() {
3. high speed 3. high speed
*/ */
#define DEFINE_TEMP_SENSOR(name, type, pin, additional) \ #define DEFINE_TEMP_SENSOR(name, type, pin, additional) \
pin ## _PORT->MODER |= (GPIO_MODER_MODER0 << ((pin ## _PIN) << 1)); \ SET_MODE(pin, 0x3); \
pin ## _PORT->PUPDR &= ~(GPIO_PUPDR_PUPDR0 << ((pin ## _PIN) << 1)); \ PULL_OFF(pin); \
pin ## _PORT->OSPEEDR |= (GPIO_OSPEEDER_OSPEEDR0 << ((pin ## _PIN) << 1)); SET_OSPEED(pin, 0x3);
#include "config_wrapper.h" #include "config_wrapper.h"
#undef DEFINE_TEMP_SENSOR #undef DEFINE_TEMP_SENSOR
@ -144,38 +145,18 @@ void init_dma() {
* halfword for memory and periphal: the 12bit ADC is 16bit right aligned * halfword for memory and periphal: the 12bit ADC is 16bit right aligned
* memory inc.: we read any adc and doing a step of 16bits after each conversion * memory inc.: we read any adc and doing a step of 16bits after each conversion
* circular mode: repeat until inf * circular mode: repeat until inf
* double buffer mode: we write to one adress and read the other
*/ */
tmp_CR &= ~(DMA_SxCR_DIR); tmp_CR &= ~(DMA_SxCR_DIR);
tmp_CR |= DMA_SxCR_MSIZE_0 | tmp_CR |= DMA_SxCR_MSIZE_0 |
DMA_SxCR_PSIZE_0 | DMA_SxCR_PSIZE_0 |
DMA_SxCR_MINC | DMA_SxCR_MINC |
DMA_SxCR_CIRC | DMA_SxCR_CIRC;
DMA_SxCR_TCIE;
DMA2_Stream4->CR = tmp_CR; DMA2_Stream4->CR = tmp_CR;
// 10. Enable DMA-Stream // 10. Enable DMA-Stream
DMA2_Stream4->CR |= DMA_SxCR_EN; DMA2_Stream4->CR |= DMA_SxCR_EN;
while(!(DMA2_Stream4->CR & DMA_SxCR_EN)); while(!(DMA2_Stream4->CR & DMA_SxCR_EN));
NVIC_SetPriority(DMA2_Stream4_IRQn,
NVIC_EncodePriority(NVIC_GetPriorityGrouping(), 3, 1));
NVIC_EnableIRQ(DMA2_Stream4_IRQn); // Enable interrupt generally.
}
/**
DMA2 Stream4 interrupt.
Happens every time the complete stream is written.
In that case, we can turn of the ADC until we read it.
Must have the same name as in cmsis-startup_stm32f411xe.s.
*/
void DMA2_Stream4_IRQHandler(void) {
DMA2->HIFCR = DMA_HIFCR_CTCIF4;
ADC1->CR2 &= ~(ADC_CR2_DMA); // clear DMA flag; we restart it in start_adc()
} }
/** Read analog value. /** Read analog value.
@ -212,6 +193,7 @@ uint16_t analog_read(uint8_t index) {
Start a new ADC conversion. Start a new ADC conversion.
*/ */
void start_adc() { void start_adc() {
ADC1->CR2 &= ~(ADC_CR2_DMA);
ADC1->CR2 |= ADC_CR2_DMA; ADC1->CR2 |= ADC_CR2_DMA;
} }