灵动微 MM32 多路ADC-DMA配置

一、问题

最近在使用灵动微的MM32，当用多路ADC-DMA时，出现了一些问题，所以在此记录一下
总结下来，处理了下面几个问题（这里的问题是拿到最新的SDK包，参考example没办法解决的）

1. 多路通道对应的DMA内存不明确，例如CH0对应DMA的第二个字节，CH1却对应第一字节
2. 多个通道数值接近

二、解决方法

1. 使用任意通道

       ADC_ANY_NUM_Config(ADC1,3);//一共4通道
       ADC1->ANYCR |=  ADC_ANY_CR_CHANY_MDEN;//开启任意通道
   	
   	///设置通道的顺序
       ADC_ANY_CH_Config(ADC1,0,ADC_Channel_0);
       ADC_ANY_CH_Config(ADC1,1,ADC_Channel_1);
       ADC_ANY_CH_Config(ADC1,2,ADC_Channel_2);
       ADC_ANY_CH_Config(ADC1,3,ADC_Channel_Vrefint);
   

2. 这个问题，是因为引脚悬空导致了，举个例子，若PA1有确切电平， PA2 PA3
   悬空，则PA2 PA3得到的数据会跟随PA1变化，只有一点点区别（细微差别）

三、整体代码

void adc_dma_init()
{
    DMA_InitTypeDef DMA_InitStruct;

    RCC_AHBPeriphClockCmd(RCC_AHBENR_DMA1, ENABLE);
    DMA_DeInit(DMA1_Channel1);
    DMA_StructInit(&DMA_InitStruct);
    //DMA transfer peripheral address
    DMA_InitStruct.DMA_PeripheralBaseAddr = (u32) & (ADC1->DR);
    //DMA transfer memory address
    DMA_InitStruct.DMA_MemoryBaseAddr = (u32)&adcBuf;
    //DMA transfer direction from peripheral to memory
    DMA_InitStruct.DMA_DIR = DMA_DIR_PeripheralSRC;
    //DMA cache size
    DMA_InitStruct.DMA_BufferSize = ADC_DMA_BUF_SIZE;
    //After receiving the data, the peripheral address is forbidden to move
    //backward
    DMA_InitStruct.DMA_PeripheralInc = DMA_PeripheralInc_Disable;
    //After receiving the data, the memory address is shifted backward
    DMA_InitStruct.DMA_MemoryInc = DMA_MemoryInc_Enable;
    //Define the peripheral data width to 16 bits
    DMA_InitStruct.DMA_PeripheralDataSize = DMA_PeripheralDataSize_HalfWord;
    //Define the memory data width to 16 bits
    DMA_InitStruct.DMA_MemoryDataSize = DMA_MemoryDataSize_HalfWord;
    //Cycle conversion mode
    DMA_InitStruct.DMA_Mode = DMA_Mode_Circular;
    //DMA priority is high
    DMA_InitStruct.DMA_Priority = DMA_Priority_High;
    //M2M mode is disabled
    DMA_InitStruct.DMA_M2M = DMA_M2M_Disable;
    DMA_InitStruct.DMA_Auto_reload = DMA_Auto_Reload_Disable;
    DMA_Init(DMA1_Channel1, &DMA_InitStruct);
    DMA_Cmd(DMA1_Channel1, ENABLE);

    ADC_InitTypeDef  ADC_InitStruct;
    ADC_StructInit(&ADC_InitStruct);

    //Initialize PA1 to analog input mode
    //Enable ADC clock
    RCC_APB2PeriphClockCmd(RCC_APB2ENR_ADC1, ENABLE);
    ADC_InitStruct.ADC_Resolution = ADC_Resolution_12b;
    //ADC prescale factor
    ADC_InitStruct.ADC_PRESCARE = ADC_PCLK2_PRESCARE_17;
    //Set ADC mode to continuous conversion mode
    ADC_InitStruct.ADC_Mode = ADC_Mode_Continue;
    //AD data right-justified
    ADC_InitStruct.ADC_DataAlign = ADC_DataAlign_Right;
    ADC_InitStruct.ADC_ExternalTrigConv = ADC_ExternalTrigConv_T1_CC1;
    ADC_Init(ADC1, &ADC_InitStruct);

    GPIO_InitTypeDef GPIO_InitStruct;
    RCC_AHBPeriphClockCmd(RCC_AHBENR_GPIOA, ENABLE);
    RCC_AHBPeriphClockCmd(RCC_AHBENR_GPIOC, ENABLE);
    GPIO_StructInit(&GPIO_InitStruct);
    GPIO_InitStruct.GPIO_Pin  =  GPIO_Pin_0|GPIO_Pin_1|GPIO_Pin_2|GPIO_Pin_3|GPIO_Pin_4|GPIO_Pin_5|GPIO_Pin_6;
    GPIO_InitStruct.GPIO_Speed = GPIO_Speed_50MHz;
    GPIO_InitStruct.GPIO_Mode = GPIO_Mode_AIN;
    GPIO_Init(GPIOA, &GPIO_InitStruct);

    //PC3  ADC_IN13
    GPIO_InitStruct.GPIO_Pin  =  GPIO_Pin_3;
    GPIO_Init(GPIOC, &GPIO_InitStruct);

    //Enable the channel
    ADC_RegularChannelConfig(ADC1, ADC_Channel_0, 0, ADC_Samctl_240_5);
    ADC_RegularChannelConfig(ADC1, ADC_Channel_1, 0, ADC_Samctl_240_5);
    ADC_RegularChannelConfig(ADC1, ADC_Channel_2, 0, ADC_Samctl_240_5);
   // ADC_RegularChannelConfig(ADC1, ADC_Channel_4, 0, ADC_Samctl_240_5);
   // ADC_RegularChannelConfig(ADC1, ADC_Channel_5, 0, ADC_Samctl_240_5);
    //ADC_RegularChannelConfig(ADC1, ADC_Channel_5, 0, ADC_Samctl_240_5);
    //ADC_RegularChannelConfig(ADC1, ADC_Channel_6, 0, ADC_Samctl_240_5);
   // ADC_RegularChannelConfig(ADC1, 13, 0, ADC_Samctl_240_5);//通道13
    ADC_RegularChannelConfig(ADC1, ADC_Channel_Vrefint, 0, ADC_Samctl_240_5);

    
    ADC_ANY_CH_Config(ADC1,0,ADC_Channel_0);
    ADC_ANY_CH_Config(ADC1,1,ADC_Channel_1);
    ADC_ANY_CH_Config(ADC1,2,ADC_Channel_2);
    ADC_ANY_CH_Config(ADC1,3,ADC_Channel_Vrefint);

    ADC_ANY_NUM_Config(ADC1,3);//
    ADC1->ANYCR |=  ADC_ANY_CR_CHANY_MDEN;//开启任意通道

    ADC_TempSensorVrefintCmd(ENABLE);


    //Enable ADCDMA
    ADC_DMACmd(ADC1, ENABLE);
    //Enable AD conversion
    ADC_Cmd(ADC1, ENABLE);

    ADC_SoftwareStartConvCmd(ADC1, ENABLE);

}