Can't generate sine wave using DAC and DMA on STM32

Question

I have problem generating sine wave with my STM32F303K8 nucleo board. In my opinion, everything is configured as it should be, but I can see gnd on the oscilliscope, so it is not working. Maybe anybody has an idea why? Heres the code:

#include "stm32f30x.h"
#include <stdio.h>

#define DAC_DHR12R2_ADDRESS      0x40007414

const uint16_t Sine12bit[32] = {
    2047, 2447, 2831, 3185, 3498, 3750, 3939, 4056, 4095, 4056,
    3939, 3750, 3495, 3185, 2831, 2447, 2047, 1647, 1263,  909,
     599,  344,  155,   38,    0,   38,  155,  344,  599,  909,
     263, 1647};

DAC_InitTypeDef             DAC_InitStructure;
DMA_InitTypeDef             DMA_InitStructure;
GPIO_InitTypeDef            GPIO_InitStructure;
TIM_TimeBaseInitTypeDef     TIM_TimeBaseStructure;

static void DMA_setup(void){
    DMA_InitStructure.DMA_PeripheralBaseAddr = DAC_DHR12R2_ADDRESS;
    DMA_InitStructure.DMA_MemoryBaseAddr = (uint32_t)&Sine12bit;
    DMA_InitStructure.DMA_DIR = DMA_DIR_PeripheralDST;
    DMA_InitStructure.DMA_BufferSize = 32;
    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_M2M = DMA_M2M_Disable;
    DMA_Init(DMA1_Channel1, &DMA_InitStructure);
    DMA_Cmd(DMA1_Channel1, ENABLE);
    DAC_DMACmd(DAC1, DAC_Channel_1, ENABLE);
}

static void DAC_setup(void){
    RCC_APB1PeriphClockCmd(RCC_APB1Periph_DAC, ENABLE);
    RCC_AHBPeriphClockCmd(RCC_AHBPeriph_GPIOA, ENABLE);

    GPIO_InitStructure.GPIO_Pin =  GPIO_Pin_4;
    GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AN;
    GPIO_InitStructure.GPIO_PuPd = GPIO_PuPd_NOPULL;
    GPIO_Init(GPIOA, &GPIO_InitStructure);

    DAC_InitStructure.DAC_Trigger = DAC_Trigger_T6_TRGO;
    DAC_InitStructure.DAC_WaveGeneration = DAC_WaveGeneration_None;
    DAC_InitStructure.DAC_Buffer_Switch = DAC_BufferSwitch_Disable;
    DAC_Init(DAC1, DAC_Channel_1, &DAC_InitStructure);
}

static void TIMER_setup(void){
  RCC_APB1PeriphClockCmd(RCC_APB1Periph_TIM6, ENABLE);

  TIM_TimeBaseStructInit(&TIM_TimeBaseStructure);
  TIM_TimeBaseStructure.TIM_Period = 100;
  TIM_TimeBaseStructure.TIM_Prescaler = 0;
  TIM_TimeBaseStructure.TIM_ClockDivision = 0;
  TIM_TimeBaseStructure.TIM_CounterMode = TIM_CounterMode_Up;
  TIM_TimeBaseInit(TIM6, &TIM_TimeBaseStructure);

  TIM_SelectOutputTrigger(TIM6, TIM_TRGOSource_Update);
  TIM_Cmd(TIM6, ENABLE);
}

int main(void){
    TIMER_setup();
    DAC_setup();
    DMA_setup();
    DAC_Cmd(DAC1, DAC_Channel_1, ENABLE);
}

What happen after main? if you dont have a endless loop in a freestanding environment, you IP counts up till he reach the next garbages values and interpret them — 12431234123412341234123, Jun 12 '16 at 14:49

score 0 · Answer 1 · answered Jun 12 '16 at 10:52

Your program does only some settings, still missing the "working" part - that would be a timer interrupt and inside the interrupt a single value from Sin12 array to be sent to the DAC, not matter how. Start first without DMA and when OK you may improve it by changing to DMA support.

Can't generate sine wave using DAC and DMA on STM32

1 Answers1