做数字滤波器，使用adc+dma采样数据，处理后通过dac+dma输出，两个dma会影响滤波函数的问题。

luoye240 · 发表于 2022-6-19 11:34:31

如题，想做一个数字滤波器，adc采样数据后再通过dac把滤波后的信号发送出去，然后卡在两个dma上面了。目前是在用adc+dma采样数据，通过滤波函数处理后串口发送出去，同时dac输出一个与” adc采样数据无关 “的正弦波，观察dac+dma能否正常工作。
遇到的问题是，dac在关闭的时候，adc接受的一个三次谐波，经过滤波函数，滤波函数正常工作，将滤波后信号串口打印，是一个正弦波。
dac在正常工作并输出正弦波的时候，adc同样接受的一个三次谐波，经过滤波函数，此时滤波函数滤波后的信号变为三次谐波，就是没起到作用，求大佬解惑。
下面是adc+dma的代码配置

#include "adc.h"
#include "delay.h"
#include <string.h>
#include "filter.h"
#define TEST_LENGTH_SAMPLES 300
extern u16 ADC_Raw[TEST_LENGTH_SAMPLES];
u16 temp[TEST_LENGTH_SAMPLES];
extern float testInput_f32_50Hz_200Hz[TEST_LENGTH_SAMPLES];
//初始化ADC
void DMA_Config(DMA_Stream_TypeDef *DMA_Streamx,uint32_t chx,uint32_t par,uint32_t mar,uint16_t ndtr,uint32_t pri)
{
DMA_InitTypeDef DMA_InitStructure;
if((u32)DMA_Streamx>(u32)DMA2) //得到当前stream是属于DMA2还是DMA1
{
RCC_AHB1PeriphClockCmd(RCC_AHB1Periph_DMA2,ENABLE); //DMA2时钟使能
}else
{
RCC_AHB1PeriphClockCmd(RCC_AHB1Periph_DMA1,ENABLE); //DMA1时钟使能
}
DMA_DeInit(DMA_Streamx);
while (DMA_GetCmdStatus(DMA_Streamx) != DISABLE){} //等待DMA可配置
/* 配置 DMA Stream */
DMA_InitStructure.DMA_Channel = chx; //通道选择
DMA_InitStructure.DMA_PeripheralBaseAddr = par; //DMA外设地址
DMA_InitStructure.DMA_Memory0BaseAddr = mar; //DMA 存储器0地址
DMA_InitStructure.DMA_DIR = DMA_DIR_PeripheralToMemory; //外设到内存
DMA_InitStructure.DMA_BufferSize = ndtr; //数据传输量
DMA_InitStructure.DMA_PeripheralInc = DMA_PeripheralInc_Disable; //外设非增量模式
DMA_InitStructure.DMA_MemoryInc = DMA_MemoryInc_Enable; //存储器增量模式
DMA_InitStructure.DMA_PeripheralDataSize = DMA_PeripheralDataSize_HalfWord; //外设数据长度:16位
DMA_InitStructure.DMA_MemoryDataSize = DMA_MemoryDataSize_HalfWord; //存储器数据长度:16位
DMA_InitStructure.DMA_Mode = DMA_Mode_Circular; //使用循环模式
DMA_InitStructure.DMA_Priority = pri; //优先级
DMA_InitStructure.DMA_FIFOMode = DMA_FIFOMode_Disable;
DMA_InitStructure.DMA_FIFOThreshold = DMA_FIFOThreshold_Full;
DMA_InitStructure.DMA_MemoryBurst = DMA_MemoryBurst_Single; //存储器突发单次传输
DMA_InitStructure.DMA_PeripheralBurst = DMA_PeripheralBurst_Single; //外设突发单次传输
DMA_Init(DMA_Streamx, &DMA_InitStructure); //初始化DMA Stream
/* DMA2_Stream0 enable */
DMA_ClearITPendingBit(DMA2_Stream0, DMA_IT_TC);
DMA_ITConfig(DMA2_Stream0, DMA_IT_TC, ENABLE);
DMA_Cmd(DMA_Streamx, ENABLE);
}
//初始化ADC3IN7引脚
void ADCInit_GPIO(void)
{
GPIO_InitTypeDef GPIO_InitStructure;
RCC_AHB1PeriphClockCmd(RCC_AHB1Periph_GPIOA, ENABLE);
GPIO_InitStructure.GPIO_Pin = GPIO_Pin_0;
GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AN;
GPIO_InitStructure.GPIO_PuPd = GPIO_PuPd_NOPULL;
GPIO_Init(GPIOA, &GPIO_InitStructure);
}
void ADC_Config(void)
{
ADC_CommonInitTypeDef ADC_CommonInitStructure;
ADC_InitTypeDef ADC_InitStructure;
RCC_APB2PeriphClockCmd(RCC_APB2Periph_ADC3, ENABLE);
RCC_APB2PeriphResetCmd(RCC_APB2Periph_ADC3,ENABLE);
RCC_APB2PeriphResetCmd(RCC_APB2Periph_ADC3,DISABLE);
ADC_CommonInitStructure.ADC_Mode = ADC_Mode_Independent;
ADC_CommonInitStructure.ADC_TwoSamplingDelay = ADC_TwoSamplingDelay_5Cycles;
ADC_CommonInitStructure.ADC_DMAAccessMode = ADC_DMAAccessMode_Disabled;
ADC_CommonInitStructure.ADC_Prescaler = ADC_Prescaler_Div4;
ADC_CommonInit(&ADC_CommonInitStructure);
ADC_InitStructure.ADC_Resolution = ADC_Resolution_12b;
ADC_InitStructure.ADC_ScanConvMode = ENABLE;
ADC_InitStructure.ADC_ContinuousConvMode = DISABLE;
ADC_InitStructure.ADC_ExternalTrigConvEdge = ADC_ExternalTrigConvEdge_Rising;
ADC_InitStructure.ADC_ExternalTrigConv = ADC_ExternalTrigConv_T2_TRGO;//定时器2外部触发
ADC_InitStructure.ADC_DataAlign = ADC_DataAlign_Right;
ADC_InitStructure.ADC_NbrOfConversion = 1; //M
ADC_Init(ADC3, &ADC_InitStructure);
delay_ms(5);
ADC_RegularChannelConfig(ADC3, ADC_Channel_0, 1, ADC_SampleTime_480Cycles);
ADC_DMARequestAfterLastTransferCmd(ADC3, ENABLE);//源数据变化时开启DMA传输
ADC_DMACmd(ADC3, ENABLE); //使能ADC的DMA传输
ADC_Cmd(ADC3, ENABLE);
}
void NVIC_Config(void)
{
NVIC_InitTypeDef NVIC_InitStructure;
NVIC_PriorityGroupConfig(NVIC_PriorityGroup_1);//最高一位用于配置抢占优先级，低三位用于配置响应优先级
NVIC_InitStructure.NVIC_IRQChannel = TIM2_IRQn;
NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority=1;
NVIC_InitStructure.NVIC_IRQChannelSubPriority =1;
NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE;
NVIC_Init(&NVIC_InitStructure);
NVIC_InitStructure.NVIC_IRQChannel = DMA2_Stream0_IRQn;
NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority=0;
NVIC_InitStructure.NVIC_IRQChannelSubPriority =1;
NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE;
NVIC_Init(&NVIC_InitStructure);
}
void Timer_Init(void)
{
TIM_TimeBaseInitTypeDef TIM_TimeBaseStructure;
RCC_APB1PeriphClockCmd(RCC_APB1Periph_TIM2, ENABLE);
TIM_Cmd(TIM2, DISABLE);
TIM_TimeBaseStructInit(&TIM_TimeBaseStructure);
//T=(84 * 625) / 84M = 625us = 20ms/32,1600HZ
TIM_TimeBaseStructure.TIM_Prescaler = 4199 ;//84-1;
TIM_TimeBaseStructure.TIM_Period = 1;//312500/CurrentFreq - 1;
TIM_TimeBaseStructure.TIM_ClockDivision = TIM_CKD_DIV1;
TIM_TimeBaseStructure.TIM_CounterMode = TIM_CounterMode_Up ;
TIM_TimeBaseInit(TIM2, &TIM_TimeBaseStructure);
TIM_ARRPreloadConfig(TIM2, ENABLE);
TIM_SelectOutputTrigger(TIM2, TIM_TRGOSource_Update);
TIM_Cmd(TIM2, ENABLE);
}
void TIM2_IRQHandler(void)
{
if(TIM_GetITStatus(TIM2, TIM_IT_Update))
{
//LED0=~LED0;
TIM_ClearITPendingBit(TIM2, TIM_IT_Update);
}
}
u16 adc_cov;
u16 ADC3_IN7_RES;
void DMA2_Stream0_IRQHandler(void)
{
u16 i=0;
if(DMA_GetITStatus(DMA2_Stream0, DMA_IT_TCIF0))
{
memcpy(temp, ADC_Raw, sizeof(u16)*TEST_LENGTH_SAMPLES);
for(i=0;i<TEST_LENGTH_SAMPLES;i++){
testInput_f32_50Hz_200Hz[i]=(float)temp[i];
}
printf("\r\n-------arm_fir_f32_lp();-------\r\n");
arm_fir_f32_lp();
printf("\r\n------arm_fir_f32_lp();--------\r\n");
DMA_ClearITPendingBit(DMA2_Stream0, DMA_IT_TCIF0);
}
}

复制代码

以下是dac+dma和定时器的配置

//dac.c
#include "dac.h"
//DAC通道1输出初始化
void DAC_Mode_Init(u16 mar)
{
DAC_InitTypeDef DAC_InitType;
DMA_InitTypeDef DMA_InitStre;
GPIO_InitTypeDef GPIO_InitStructure;
RCC_AHB1PeriphClockCmd(RCC_AHB1Periph_GPIOA, ENABLE);//使能GPIOA时钟
RCC_APB1PeriphClockCmd(RCC_APB1Periph_DAC, ENABLE);//使能DAC时钟
RCC_AHB1PeriphClockCmd(RCC_AHB1Periph_DMA1, ENABLE);//DMA时钟
GPIO_InitStructure.GPIO_Pin = GPIO_Pin_4;
GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AN;//模拟输入
GPIO_InitStructure.GPIO_PuPd = GPIO_PuPd_NOPULL;//下拉
GPIO_InitStructure.GPIO_Speed = GPIO_Speed_100MHz;
GPIO_InitStructure.GPIO_OType = GPIO_OType_PP;
GPIO_Init(GPIOA, &GPIO_InitStructure);//初始化
/************************* 通道1 ***************************/
//使用DMA模式-寄存器到外设
DAC_InitType.DAC_Trigger=DAC_Trigger_T2_TRGO; //必须使用触发功能 TEN1=0
DAC_InitType.DAC_WaveGeneration=DAC_WaveGeneration_None;//不使用波形发生
DAC_InitType.DAC_LFSRUnmask_TriangleAmplitude=DAC_LFSRUnmask_Bit0;//屏蔽、幅值设置
DAC_InitType.DAC_OutputBuffer=DAC_OutputBuffer_Disable; //DAC1输出缓存关闭 BOFF1=1
DAC_Init(DAC_Channel_1,&DAC_InitType); //初始化DAC通道1
DAC_Cmd(DAC_Channel_1, ENABLE); //使能DAC通道1
//DMA初始化
DMA_DeInit(DMA1_Stream5);//复位
DMA_InitStre.DMA_PeripheralBaseAddr=(uint32_t)&(DAC->DHR12R1);//外设 DAC1_DR
DMA_InitStre.DMA_PeripheralBurst=DMA_PeripheralBurst_Single;
DMA_InitStre.DMA_PeripheralDataSize=DMA_PeripheralDataSize_HalfWord;//半字
DMA_InitStre.DMA_PeripheralInc=DMA_PeripheralInc_Disable;//外设地址增加失能
DMA_InitStre.DMA_Memory0BaseAddr=mar; //内存地址
DMA_InitStre.DMA_MemoryInc=DMA_MemoryInc_Enable;//寄存器（变量）地址增加
DMA_InitStre.DMA_MemoryDataSize=DMA_MemoryDataSize_HalfWord;//半字
DMA_InitStre.DMA_MemoryBurst=DMA_MemoryBurst_Single;
DMA_InitStre.DMA_Channel=DMA_Channel_7;
DMA_InitStre.DMA_DIR=DMA_DIR_MemoryToPeripheral;//寄存器到外设输出
DMA_InitStre.DMA_BufferSize=300;//一个输出循环中数据长度
DMA_InitStre.DMA_Mode=DMA_Mode_Circular;//循环发送
DMA_InitStre.DMA_Priority=DMA_Priority_High;
DMA_InitStre.DMA_FIFOMode=DMA_FIFOMode_Disable;
DMA_InitStre.DMA_FIFOThreshold=DMA_FIFOThreshold_1QuarterFull;
DMA_Init(DMA1_Stream5,&DMA_InitStre);//初始化
DMA_Cmd(DMA1_Stream5,ENABLE);//DMA使能
DAC_DMACmd(DAC_Channel_1, ENABLE);//DAC-DMA使能
}
//time.c
#include "timer.h"
#include "led.h"
//通用定时器4中断初始化
//arr：自动重装值。
//psc：时钟预分频数
//定时器溢出时间计算方法:Tout=((arr+1)*(psc+1))/Ft us.
//Ft=定时器工作频率,单位:Mhz
//这里使用的是定时器2
void TIM2_Int_Init(u16 arr,u16 psc)
{
TIM_TimeBaseInitTypeDef TIM_TimeBaseInitStructure;
NVIC_InitTypeDef NVIC_InitStructure;
RCC_APB1PeriphClockCmd(RCC_APB1Periph_TIM2,ENABLE); ///使能TIM2时钟
TIM_DeInit(TIM2); // 初始化
TIM_TimeBaseStructInit(&TIM_TimeBaseInitStructure); // 初始化
TIM_TimeBaseInitStructure.TIM_Period = arr; //自动重装载值
TIM_TimeBaseInitStructure.TIM_Prescaler=psc; //定时器分频
TIM_TimeBaseInitStructure.TIM_CounterMode=TIM_CounterMode_Up; //向上计数模式
TIM_TimeBaseInitStructure.TIM_ClockDivision=TIM_CKD_DIV1;
TIM_TimeBaseInit(TIM2,&TIM_TimeBaseInitStructure);//初始化TIM2
TIM_SelectOutputTrigger(TIM2,TIM_TRGOSource_Update); // **与上一方案不同**
TIM_Cmd(TIM2,ENABLE); //使能定时器2
}

复制代码

以下是滤波函数

#include "filter.h"
#include "arm_math.h"
#define TEST_LENGTH_SAMPLES 300 /* 采样点数 */
#define BLOCK_SIZE 1 /* 调用一次arm_fir_f32处理的采样点个数 */
#define NUM_TAPS 29 /* 滤波器系数个数 */
float32_t testInput_f32_50Hz_200Hz[TEST_LENGTH_SAMPLES]; /* 采样点 */
static float32_t testOutput[TEST_LENGTH_SAMPLES]; /* 滤波后的输出 */
static float32_t firStateF32[BLOCK_SIZE + NUM_TAPS - 1]; /* 状态缓存，大小numTaps + blockSize - 1*/
uint32_t blockSize = BLOCK_SIZE;
uint32_t numBlocks = TEST_LENGTH_SAMPLES/BLOCK_SIZE; /* 需要调用arm_fir_f32的次数 */
const float32_t firCoeffs32LP[NUM_TAPS] = {
0.001066399611256, 0.002126085729052, 0.003159337947181, 0.003059846159226,
-1.968950437715e-18, -0.00705866005337, -0.01651859315877, -0.02329385602413,
-0.01997951839664,5.751341766627e-18, 0.03857458762271, 0.09055123279738,
0.1441009644858, 0.1844676143613, 0.199489117838, 0.1844676143613,
0.1441009644858, 0.09055123279738, 0.03857458762271,5.751341766627e-18,
-0.01997951839664, -0.02329385602413, -0.01651859315877, -0.00705866005337,
-1.968950437715e-18, 0.003059846159226, 0.003159337947181, 0.002126085729052,
0.001066399611256
};
void arm_fir_f32_lp(void)
{
uint32_t i;
arm_fir_instance_f32 S;
float32_t *inputF32, *outputF32;
/* 初始化输入输出缓存指针 */
inputF32 = &testInput_f32_50Hz_200Hz[0];
outputF32 = &testOutput[0];
/* 初始化结构体S */
arm_fir_init_f32(&S,
NUM_TAPS,
(float32_t *)&firCoeffs32LP[0],
&firStateF32[0],
blockSize);
/* 实现FIR滤波，这里每次处理1个点 */
for(i=0; i < numBlocks; i++)
{
arm_fir_f32(&S, inputF32 + (i * blockSize), outputF32 + (i * blockSize), blockSize);
}
/* 打印滤波后结果 */
for(i=0; i<TEST_LENGTH_SAMPLES; i++)
{
printf("%f\r\n", outputF32[i]);
}
}