ADS7953应用

方法1

/*******************************************************************************
时钟频率=2.5M；时钟空闲为低，时钟上降沿采集AD数据和传数；
*******************************************************************************/
void SPI3_ADS7953_Config(void)
{
GPIO_InitTypeDef GPIO_InitStructure;
SPI_InitTypeDef SPI_InitStructure;
RCC_APB1PeriphClockCmd(RCC_APB1Periph_SPI3,ENABLE); //使能时钟
//配置引脚：PD0为CS，
GPIO_InitStructure.GPIO_Pin = GPIO_Pin_0;//
GPIO_InitStructure.GPIO_Mode = GPIO_Mode_OUT;//
GPIO_InitStructure.GPIO_OType = GPIO_OType_PP;//í?íìê?3?
GPIO_InitStructure.GPIO_Speed = GPIO_Speed_100MHz;//100MHz
GPIO_InitStructure.GPIO_PuPd = GPIO_PuPd_UP;//é?à-
GPIO_Init(GPIOD, &GPIO_InitStructure);//3?ê??ˉ
//配置特殊引脚，PC10：为SPISCLK，PC11：SPIMISO，PC12：SPIMOSI
GPIO_InitStructure.GPIO_Pin = GPIO_Pin_10 | GPIO_Pin_11 | GPIO_Pin_12;//PC10~12?′ó?1|?üê?3? GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF;//?′ó?1|?ü
GPIO_InitStructure.GPIO_OType = GPIO_OType_PP;//í?íìê?3?
GPIO_InitStructure.GPIO_Speed = GPIO_Speed_100MHz;//100MHz
GPIO_InitStructure.GPIO_PuPd = GPIO_PuPd_UP;//é?à-
GPIO_Init(GPIOC, &GPIO_InitStructure);//3?ê??ˉ
GPIO_PinAFConfig(GPIOC,GPIO_PinSource10,GPIO_AF_SPI3); //PC10?′ó??a SPI3
GPIO_PinAFConfig(GPIOC,GPIO_PinSource11,GPIO_AF_SPI3); //PC11?′ó??a SPI3
GPIO_PinAFConfig(GPIOC,GPIO_PinSource12,GPIO_AF_SPI3); //PC12?′ó??a SPI3
RCC_APB1PeriphResetCmd(RCC_APB1Periph_SPI3,ENABLE);//?′??SPI1
RCC_APB1PeriphResetCmd(RCC_APB1Periph_SPI3,DISABLE);//í￡?1?′??SPI1

SPI_InitStructure.SPI_Direction = SPI_Direction_2Lines_FullDuplex; //éè??SPIμ￥?ò?ò?????òμ?êy?Y?￡ê?:SPIéè???a???????òè???1¤
SPI_InitStructure.SPI_Mode = SPI_Mode_Master; //éè??SPI1¤×÷?￡ê?:éè???a?÷SPI
SPI_InitStructure.SPI_DataSize = SPI_DataSize_16b ; //16Bit长度
SPI_InitStructure.SPI_CPOL = SPI_CPOL_Low; //时钟空闲为低
SPI_InitStructure.SPI_CPHA = SPI_CPHA_1Edge; //第一个边沿（上升沿）采集数据
SPI_InitStructure.SPI_NSS = SPI_NSS_Soft; //NSSD?o?óéó2?t￡¨NSS1ü??￡??1ê?èí?t￡¨ê1ó?SSI??￡?1üàí:?ú2?NSSD?o?óDSSI??????
SPI_InitStructure.SPI_BaudRatePrescaler = SPI_BaudRatePrescaler_16; //?¨ò?2¨ì??ê?¤·??μμ??μ:2¨ì??ê?¤·??μ?μ?a32:40/16=2.5
SPI_InitStructure.SPI_FirstBit = SPI_FirstBit_MSB; //???¨êy?Y′?ê?′óMSB???1ê?LSB???aê?:êy?Y′?ê?′óMSB???aê?
SPI_InitStructure.SPI_CRCPolynomial = 7; //CRC?μ????μ??à??ê?
SPI_Init(SPI3, &SPI_InitStructure); //?ù?YSPI_InitStruct?D???¨μ?2?êy3?ê??ˉíaéèSPIx??′??÷
SPI_Cmd(SPI3, ENABLE); //ê1?üSPIíaéè
}

u16 SPI3H_SendByte(u16 byte)
{
u16 Result;

while(SPI_I2S_GetFlagStatus(SPI3,SPI_I2S_FLAG_TXE) == RESET);

SPI_I2S_SendData(SPI3, byte);

while (SPI_I2S_GetFlagStatus(SPI3,SPI_I2S_FLAG_RXNE) == RESET);

Result = SPI_I2S_ReceiveData(SPI3);

return Result;
}
/*
手动采集AD，CMD = 0x1840；Ch为通道号
*/
u16 SampleAD_ByManual_Mode(u16 Ch,u16 CMD)
{
u16 ChTemp = 0;
u16 SampleAD = 0;
ChTemp = Ch;
ChTemp = ChTemp<<7;
ChTemp = ChTemp | CMD;

CS_AD_L;//片选为低
Delay_Time(200);//延时
SampleAD = SPI3H_SendByte(ChTemp); Delay_Time(200);//延时
CS_AD_H;//片选为高

return SampleAD;
}
/*
ManualAD = 0x1140
*/
void Initilzie_Sample_AD(void)
{
u16 i = 0;
u16 Ch = 0;
u16 SampleAD[3]={0,0,0};
u16 StartT;
while(i<3)
{
StartT = GlobalVariable.RealTimer;
while(UniversalTimer(StartT)<2);//延时20ms
SampleAD[i] = SampleAD_ByManual_Mode(i,ManualAD);
Ch = SampleAD[i] & 0xF000;
Ch = Ch>>12;
if(Ch==i)
{
i++;
}
}
}

int main(void)
{
u16 StartT;
SPI3_ADS7953_Config();
while(1)
{
StartT = GlobalVariable.RealTimer;
while(UniversalTimer(StartT)<10);//延时100ms
Initilzie_Sample_AD();
}
}

方法2

#define CS_AD_H GPIOD->ODR = GPIOD->ODR | 0x0001#define CS_AD_L GPIOD->ODR = GPIOD->ODR & 0xFFFE#define *** GPIOC->ODR = GPIOC->ODR | 0x0400
#define *** GPIOC->ODR = GPIOC->ODR & 0xFBFF
#define SPIMO_H GPIOC->ODR = GPIOC->ODR | 0x1000
#define SPIMO_L GPIOC->ODR = GPIOC->ODR & 0xEFFF#define ReadADBit GPIOC->IDR & 0x0800

void GPIO_Configure_Initial(void)
{
GPIO_InitTypeDef GPIO_InitStructure;
GPIO_InitStructure.GPIO_Pin = GPIO_Pin_0;//PD0:CS
GPIO_InitStructure.GPIO_Mode = GPIO_Mode_OUT;//
GPIO_InitStructure.GPIO_OType = GPIO_OType_PP;//
GPIO_InitStructure.GPIO_Speed = GPIO_Speed_100MHz;//
GPIO_InitStructure.GPIO_PuPd = GPIO_PuPd_UP;//
GPIO_Init(GPIOD, &GPIO_InitStructure);//
GPIO_InitStructure.GPIO_Pin = GPIO_Pin_10 | GPIO_Pin_12;//PC10 SCLK,PC12:MOSI
GPIO_InitStructure.GPIO_Mode = GPIO_Mode_OUT;//
GPIO_InitStructure.GPIO_OType = GPIO_OType_PP;//
GPIO_InitStructure.GPIO_Speed = GPIO_Speed_100MHz;//
GPIO_InitStructure.GPIO_PuPd = GPIO_PuPd_UP;//
GPIO_Init(GPIOC, &GPIO_InitStructure);//
GPIO_InitStructure.GPIO_Pin = GPIO_Pin_11;//PC11:MISO
GPIO_InitStructure.GPIO_Mode = GPIO_Mode_IN;//
GPIO_InitStructure.GPIO_Speed = GPIO_Speed_100MHz;//
GPIO_InitStructure.GPIO_PuPd = GPIO_PuPd_UP;//
GPIO_Init(GPIOC, &GPIO_InitStructure);//}

//用IO模拟SPI时钟读写数据
u16 SPI3H_SendByte(u16 byte)
{
u16 i,j;
u16 WData = 0;
u16 RData = 0;
WData = byte;
***;
for(i=0;i<16;i++)
{
if((WData & 0x8000)==0)
{
SPIMO_L;
}
else
{
SPIMO_H;
}
for(j=0;j<5;j++);
***;
for(j=0;j<5;j++);
***;
if((ReadADBit)==0)//读取数据输入的Bit
{
RData = RData & 0xFFFE;
}
else
{
RData = RData | 0x0001;
}
RData = RData<<1;
WData = WData<<1;
}
return RData;
}

void Initilzie_Sample_AD(void)
{
u16 i = 0;
u16 Ch = 0;
u16 SampleAD[3]={0,0,0};
u16 StartT;
while(i<3)
{
StartT = GlobalVariable.RealTimer;
while(UniversalTimer(StartT)<2);//延时20ms
SampleAD[i] = SampleAD_ByManual_Mode(i,ManualAD);
Ch = SampleAD[i] & 0xF000;
Ch = Ch>>12;
if(Ch==i)
{
i++;
}
}
}

int main(void)
{
u16 StartT;
Initialize_SREG_Configuration();
while(1)
{
StartT = GlobalVariable.RealTimer;
while(UniversalTimer(StartT)<10);//延时100ms
Initilzie_Sample_AD();
}
}

/*
问题描述：
方法1采用SPI模块配置采样结果：SampleAD[0]：0x0211（AD引脚电压为0.530V），SampleAD[1]:0x13C0（AD引脚电压为1.030V），SampleAD[1]:0x2AA0（AD引脚电压为4.010V）
方法2用普通IO模拟SPI时钟采样，只能采样通道0，其结果也不对；完后采样通道1前四位始终指示的是2通道
*/

user151383853：

电路图加这么一大段的代码. 也没有说什么单片机

中间还有隔离. 先验证一下时序吧

user4560594：

回复 user151383853:

STM32单片机，方法1中注明了配置：时钟频率=2.5M；时钟空闲为低，时钟上降沿采集AD数据和传数；方法2是模拟SPI

Mickey Zhang：

回复 user4560594:

您的输入通道怎么都是悬空的？参考下datasheet Figure 2时序。