[英]STM32F3 DAC signal generation using DMA
我正在STM32f3Discovery板上编写一个程序,该程序应该使用DAC生成正弦波。 我有几个文件,在下面列出。
Utilities.h:
#ifndef UTILITIES_H
#define UTILITIES_H
/** @brief Configure GPIOE, pin 9 (LED) as output PP
*/
void GPIOE_init( void );
/** @brief Configure Timer 2, event frequency - 100Hz
*/
void Timer_init( void );
/** @brief Configure interrupt handler
*/
void NVIC_config( void );
/** @brief Configure and enable DAC channel 1 on pin PA4,
* with TIM2 TRGO as trigger
*/
void DACch1_config( void );
/** @brief Configure DMA to work with DAC
*/
void DMA_config( void );
#endif //UTILITIES_H
实用工具:
#include "utilities.h"
#include "stm32f30x.h"
const uint16_t sineWave12bit[32] = {
2048,2447,2831,3185,3495,3750,3939,4056,
4095,4056,3939,3750,3495,3185,2831,2447,
2048,1648,1264,910,600,345,156,39,
0,39,156,345,600,910,1264,1648 };
//This address is taken from reference manual for stm32f30
//See pages 53 and 439
#define DAC_DHR12RD_ADDRESS 0x40007420
void Timer_init( void ){
/* Configuring frequency of timer, thus sinus frequency */
/* Keep in mind, that system clock is set to 80Mhz */
TIM_TimeBaseInitTypeDef timer2;
RCC_APB1PeriphClockCmd(RCC_APB1Periph_TIM2, ENABLE);
TIM_TimeBaseStructInit( &timer2 );
timer2.TIM_CounterMode = TIM_CounterMode_Up;
//Setting prescaler so that timer clock will be only 10000Hz
timer2.TIM_Prescaler = 8000 - 1;
//Setting period so Timer will give signal of frequency 100Hz
timer2.TIM_Period = 100 - 1;
TIM_TimeBaseInit( TIM2, &timer2 );
//generate event when counter hits TIM_period value
TIM_SelectOutputTrigger(TIM2, TIM_TRGOSource_Update);
/* TIM2 enable counter */
TIM_Cmd(TIM2, ENABLE);
}
void NVIC_config( void ){
NVIC_InitTypeDef nvic;
nvic.NVIC_IRQChannel = TIM2_IRQn;
nvic.NVIC_IRQChannelPreemptionPriority = 0;
nvic.NVIC_IRQChannelSubPriority = 0;
nvic.NVIC_IRQChannelCmd = ENABLE;
NVIC_Init( &nvic );
}
void GPIOE_init( void ){
/* GPIOE initialization */
GPIO_InitTypeDef leds;
RCC_AHBPeriphClockCmd( RCC_AHBPeriph_GPIOE, ENABLE );
leds.GPIO_Pin = GPIO_Pin_9;
leds.GPIO_Mode = GPIO_Mode_OUT;
leds.GPIO_OType = GPIO_OType_PP;
leds.GPIO_Speed = GPIO_Speed_50MHz;
leds.GPIO_PuPd = GPIO_PuPd_NOPULL;
GPIO_Init(GPIOE, &leds);
}
void DACch1_config( void ){
/*******THERE IS ONLY ONE DAC ON STM32F30!!!!!!!!!!!!!!!!!!******************/
DAC_InitTypeDef DACch1;
GPIO_InitTypeDef DACch1_out;
/* Enable GPIOA Periph clock */
RCC_AHBPeriphClockCmd(RCC_AHBPeriph_GPIOA, ENABLE);
/* Configure PA04 as analog */
DACch1_out.GPIO_Pin = GPIO_Pin_4;
DACch1_out.GPIO_Mode = GPIO_Mode_AN;
DACch1_out.GPIO_OType = GPIO_OType_PP;
DACch1_out.GPIO_PuPd = GPIO_PuPd_NOPULL;
DACch1_out.GPIO_Speed = GPIO_Speed_50MHz;
GPIO_Init(GPIOA, &DACch1_out);
/* Enable DAC clock */
RCC_APB1PeriphClockCmd( RCC_APB1Periph_DAC, ENABLE );
/* Init the DAC_Init structure */
DAC_StructInit(&DACch1);
/* Configure DAC */
DACch1.DAC_Trigger = DAC_Trigger_T2_TRGO;
DACch1.DAC_WaveGeneration = DAC_WaveGeneration_None;
DACch1.DAC_LFSRUnmask_TriangleAmplitude = DAC_LFSRUnmask_Bits2_0;
DACch1.DAC_OutputBuffer = DAC_OutputBuffer_Disable;
/* DAC channel 1 configuration*/
DAC_Init( DAC_Channel_1, &DACch1 );
/* Enable DAC channel 1 */
DAC_Cmd( DAC_Channel_1, ENABLE);
}
void DMA_config( void ){
DMA_InitTypeDef mem2DAC;
/* Enable clock for DMA1 */
RCC_AHBPeriphClockCmd( RCC_AHBPeriph_DMA1, ENABLE );
/* Reset DMA1 channel 1 register values to default */
DMA_DeInit(DMA1_Channel1);
//Specify destination address
mem2DAC.DMA_PeripheralBaseAddr = DAC_DHR12RD_ADDRESS;
//Specify source address - LUT for sine
mem2DAC.DMA_MemoryBaseAddr = (uint32_t) &sineWave12bit;
//Set Peripheral as destination
mem2DAC.DMA_DIR = DMA_DIR_PeripheralDST;
mem2DAC.DMA_BufferSize = 32;
mem2DAC.DMA_PeripheralInc = DMA_PeripheralInc_Disable;
mem2DAC.DMA_MemoryInc = DMA_MemoryInc_Enable;
mem2DAC.DMA_PeripheralDataSize = DMA_PeripheralDataSize_Word;
mem2DAC.DMA_MemoryDataSize = DMA_MemoryDataSize_HalfWord;
mem2DAC.DMA_Mode = DMA_Mode_Circular;
mem2DAC.DMA_Priority = DMA_Priority_High;
mem2DAC.DMA_M2M = DMA_M2M_Disable;
DMA_Init( DMA1_Channel1, &mem2DAC );
/* Enable DMA1 Channel1 */
DMA_Cmd( DMA1_Channel1, ENABLE );
/* Enable DMA fo DAC channel 1*/
DAC_DMACmd( DAC_Channel_1, ENABLE );
}
main.c:
/**
******************************************************************************
* @file main.c
* @author Ac6
* @version V1.0
* @date 01-December-2013
* @brief Default main function.
******************************************************************************
*/
#include "stm32f30x.h"
#include "utilities.h"
int main(void)
{
DMA_config();
DACch1_config();
Timer_init();
while(1){
}
}
因此,从理论上讲,它应该在引脚A.04上生成正弦波。 但是,当我使用示波器查看此引脚上的电压时,它什么也没显示(地电位)。
有人知道什么地方可能出问题吗?
好吧,我修复了它。 如果其他人有兴趣,似乎可以驱动DAC_1的唯一合适的DMA通道是DMA2通道3。可以以某种方式将其重新映射到DMA1通道3,但仍在困扰着它。
编辑:
一切正常。 如果对某人有帮助,请按照以下所有必要步骤操作,以使DAC在STM32f3上正常运行:
启用timerX的时钟(必须查看哪些计时器可用于通过TRGO事件触发DAC),DMA,DAC和GPIOA。 如果要将非默认DMA用于DAC,请为SYSCFG启用时钟。
设置所需的DAC通道。 请注意,在STM32f3 Discovery上,只有1个具有2个通道的DAC。 DACch1输出为PA4,DACch2输出为PA5。
将选定的GPIOA配置为模拟输入和初始化。
配置DAC和初始化。 请记住为DAC启用DMA。
如果要更改与DAC一起使用的DMA的默认设置,请使用SYSCFG_DMAChannelRemapConfig命令。
配置DMA和初始化。
配置所需的计时器和初始化。 记住要设置TRGO中断!
下面,我包括使用非默认DMA在DACch1上生成正弦波的工作代码。
#include "utilities.h"
#include "stm32f30x.h"
const uint16_t sineWave12bit[64] = {
2048,2248,2447,2642,2831,3013,3185,3346,
3495,3630,3750,3853,3939,4007,4056,4085,
4095,4085,4056,4007,3939,3853,3750,3630,
3495,3346,3185,3013,2831,2642,2447,2248,
2048,1847,1648,1453,1264,1082,910,749,
600,465,345,242,156,88,39,10,
0,10,39,88,156,242,345,465,
600,749,910,1082,1264,1453,1648,1847 };
//This address is taken from reference manual for stm32f30
//See pages 53 and 439
#define DAC_DHR12R1_ADDRESS 0x40007408
void Timer_init( void ){
/* Configuring frequency of timer, thus sinus frequency */
/* Keep in mind, that system clock is set to 80Mhz */
TIM_TimeBaseInitTypeDef timer2;
RCC_APB1PeriphClockCmd(RCC_APB1Periph_TIM2, ENABLE);
TIM_TimeBaseStructInit( &timer2 );
timer2.TIM_CounterMode = TIM_CounterMode_Up;
//Setting prescaler so that timer clock will be only 10000Hz
timer2.TIM_Prescaler = 8000 - 1;
//Setting period so Timer will give signal of frequency 1000Hz
timer2.TIM_Period = 10 - 1;
TIM_TimeBaseInit( TIM2, &timer2 );
//generate event when counter hits TIM_period value
TIM_SelectOutputTrigger(TIM2, TIM_TRGOSource_Update);
/* TIM2 enable counter */
TIM_Cmd(TIM2, ENABLE);
}
void NVIC_config( void ){
NVIC_InitTypeDef nvic;
nvic.NVIC_IRQChannel = TIM2_IRQn;
nvic.NVIC_IRQChannelPreemptionPriority = 0;
nvic.NVIC_IRQChannelSubPriority = 0;
nvic.NVIC_IRQChannelCmd = ENABLE;
NVIC_Init( &nvic );
}
void GPIOE_init( void ){
/* GPIOE initialization */
GPIO_InitTypeDef leds;
RCC_AHBPeriphClockCmd( RCC_AHBPeriph_GPIOE, ENABLE );
leds.GPIO_Pin = GPIO_Pin_9;
leds.GPIO_Mode = GPIO_Mode_OUT;
leds.GPIO_OType = GPIO_OType_PP;
leds.GPIO_Speed = GPIO_Speed_50MHz;
leds.GPIO_PuPd = GPIO_PuPd_NOPULL;
GPIO_Init(GPIOE, &leds);
}
void DACch1_config( void ){
/*******THERE IS ONLY ONE DAC ON STM32F30!!!!!!!!!!!!!!!!!!******************/
DAC_InitTypeDef DACch1;
GPIO_InitTypeDef DACch1_out;
/* Enable GPIOA Periph clock */
RCC_AHBPeriphClockCmd(RCC_AHBPeriph_GPIOA, ENABLE);
/* Configure PA04 as analog */
DACch1_out.GPIO_Pin = GPIO_Pin_4;
DACch1_out.GPIO_Mode = GPIO_Mode_AN;
DACch1_out.GPIO_PuPd = GPIO_PuPd_NOPULL;
GPIO_Init(GPIOA, &DACch1_out);
/* Enable DAC clock */
RCC_APB1PeriphClockCmd( RCC_APB1Periph_DAC, ENABLE );
/* Init the DAC_Init structure */
DAC_StructInit(&DACch1);
/* Reset DAC configuration */
DAC_DeInit();
/* Configure DAC */
DACch1.DAC_Trigger = DAC_Trigger_T2_TRGO;
DACch1.DAC_WaveGeneration = DAC_WaveGeneration_None;
DACch1.DAC_LFSRUnmask_TriangleAmplitude = DAC_LFSRUnmask_Bits2_0;
DACch1.DAC_OutputBuffer = DAC_OutputBuffer_Enable;
/* DAC channel 1 configuration*/
DAC_Init( DAC_Channel_1, &DACch1 );
/* Enable DAC channel 1 */
DAC_Cmd( DAC_Channel_1, ENABLE);
}
void DMA_config( void ){
DMA_InitTypeDef mem2DAC;
/* Enable clock for SYSCFG in order to change DMA for DAC from
* DMA2 channel3 to DMA1 channel 3 (default is DMA2 channel 3) */
RCC_APB2PeriphClockCmd( RCC_APB2Periph_SYSCFG, ENABLE );
/* Use DMA1 channel 3 for DAC1 */
SYSCFG_DMAChannelRemapConfig( SYSCFG_DMARemap_TIM6DAC1, ENABLE );
/* Enable clock for DMA1 */
RCC_AHBPeriphClockCmd( RCC_AHBPeriph_DMA1, ENABLE );
/* Reset DMA1 channel 1 register values to default */
DMA_DeInit( DMA1_Channel3 );
mem2DAC.DMA_PeripheralBaseAddr = DAC_DHR12R1_ADDRESS;
mem2DAC.DMA_MemoryBaseAddr = (uint32_t)&sineWave12bit;
mem2DAC.DMA_DIR = DMA_DIR_PeripheralDST;
mem2DAC.DMA_BufferSize = 64;
mem2DAC.DMA_PeripheralInc = DMA_PeripheralInc_Disable;
mem2DAC.DMA_MemoryInc = DMA_MemoryInc_Enable;
mem2DAC.DMA_PeripheralDataSize = DMA_PeripheralDataSize_HalfWord;
mem2DAC.DMA_MemoryDataSize = DMA_MemoryDataSize_HalfWord;
mem2DAC.DMA_Mode = DMA_Mode_Circular;
mem2DAC.DMA_Priority = DMA_Priority_High;
mem2DAC.DMA_M2M = DMA_M2M_Disable;
DMA_Init( DMA1_Channel3, &mem2DAC );
/* Enable DMA1 Channel1 */
DMA_Cmd( DMA1_Channel3, ENABLE );
/* Enable DMA fo DAC channel 1*/
DAC_DMACmd( DAC_Channel_1, ENABLE );
}
我遇到了类似的问题。 首先检查您的MCU是否具有DAC模块。 可能没有DAC外设,在这种情况下将不会产生正弦波。 您可以在数据手册中针对您的特定微控制器封装进行检查。
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