havig在PIC24FJ256GB412中与SPI的麻烦

Question

我正在尝试配置PIC24FJ256GB412将SPI接口与ADC模块（ADS114S08）一起使用。现在，我可以通过示波器查看数据（通过测量SDI引脚）。但是SPI1BUFL没有收到正确的数据（始终接收到0x01）。以下是我用来配置SPI的相关代码。

uint8_t    DATA_S[1000]; // SPI data buffer for Receiving
uint8_t    DATA1;        // SPI data buffer for Receiving
uint16_t   DATA_counter=0;

void System_Initial(void)
{
    //Setup IO
    TRISDbits.TRISD0  = 0; //SCLK
    TRISDbits.TRISD5  = 0; //ADC RESET
    TRISDbits.TRISD10 = 0; //ADC START
    TRISDbits.TRISD11 = 1; //ADC DRDY
    TRISFbits.TRISF3  = 1; //SDI
    TRISFbits.TRISF4  = 0; //SDO

    ANSELDbits.ANSELD0  = 0; //Digital pins
    ANSELDbits.ANSELD5  = 0;
    ANSELDbits.ANSELD10 = 0;
    ANSELDbits.ANSELD11 = 0;
    ANSELFbits.ANSELF3  = 0;
    ANSELFbits.ANSELF4  = 0;
    
    //Setup SPI
    //MCU operates in 16MHz, ADC internal clk 4MHz
    SPI1BRGL    = 1;      //Baud rate = 4MHz
    SPI1CON1L   = 0x8020; //8bit mode //SCLK enable //Master Mode
    SPI1CON1H   = 0x2000; //AUDEN=0
    SPI1CON2L   = 0x0007; //8bit data

    //Setup PPS    
    __builtin_write_OSCCONL(OSCCON & 0xBF);
    _RP11R  = _RPOUT_SCK1OUT; // RP11 -> SCK1.
    RPINR20bits.SDI1R = 16;   // RP16 -> SDI1.
    _RP10R  = _RPOUT_SDO1;    // RP10 -> SDO1.
    __builtin_write_OSCCONL(OSCCON | 0x40);
    
}

//SPI1 - Set ADS114S08
void SPI1_SetADC()
{
    //set PGA
    //Input MUX Register, address = 02h
    //Gain setting Register, address = 03h
    SPI1BUFL = 0x42; //WREG at 02h
    while( SPI1STATLbits.SPIBUSY==1);
    SPI1BUFL = 0x01; //Two bytes
    while( SPI1STATLbits.SPIBUSY==1);
    SPI1BUFL = 0x01; //02h //AINP = AIN0, AINN = AIN1
    while( SPI1STATLbits.SPIBUSY==1);
    SPI1BUFL = 0x0B; //03h //PGA enabled, Gain = 011 =8
    while( SPI1STATLbits.SPIBUSY==1);
    
    //set Mode
    //Data Rate Register, address = 04h
    //Reference Control Register, address = 05h
    SPI1BUFL = 0x44; //WREG at 04h
    while( SPI1STATLbits.SPIBUSY==1);
    SPI1BUFL = 0x01; //Two bytes
    while( SPI1STATLbits.SPIBUSY==1);
    SPI1BUFL = 0x14; //04h //Continuous conversion mode //0100 : 20 SPS
    while( SPI1STATLbits.SPIBUSY==1);
    SPI1BUFL = 0x30; //05h
    while( SPI1STATLbits.SPIBUSY==1);
   
    //set Excitation Current Sources
    //Excitation Current Register1(IDACMAG), address = 06h
    //Excitation Current Register2(IDACMUX), address = 07h
    SPI1BUFL = 0x46; //WREG at 06h
    while( SPI1STATLbits.SPIBUSY==1);
    SPI1BUFL = 0x01; //Two bytes
    while( SPI1STATLbits.SPIBUSY==1);
    SPI1BUFL = 0x05; //06h //IDAC = 0101 = 500uA
    while( SPI1STATLbits.SPIBUSY==1);
    SPI1BUFL = 0xF0; //07h //use IDAC1 => AIN0
    while( SPI1STATLbits.SPIBUSY==1);
}

//SPI1 - RREG
void SPI1_RREG()
{ 
    SPI1BUFL = 0x20; //send RREG Command //read 00h
    while( SPI1STATLbits.SPIBUSY==1);
    
    SPI1BUFL = 0x00; //1 byte
    while( SPI1STATLbits.SPIBUSY==1);

    SPI1BUFL = 0x0000; //send DUMMY data
    while( SPI1STATLbits.SPIBUSY==1); //Wait Data
    uint8_t register1=  SPI1BUFL; //get data
    DATA1  = register1;
    DATA_S[DATA_counter%1000] = register1;
}

int main(void)
{
    System_Initial();

    LATDbits.LATD10 = 0; //ADC START=0
    LATDbits.LATD5 = 0;  //ADC RESET=0 //Enter RESET Status
    
    uint32_t loop = 0;
    loop = 4*4;         //MCU 16Mhz, ADC internal clk 4Mhz
    while (loop--);     //wait 4clk => ADS114S08 tw(RSL)
    LATDbits.LATD5 = 1; //ADC RESET low -> high //Enter Standby Mode
    
    loop=4096*4;
    while (loop--);     //wait 4096clk => ADS114S08 td(RSSC)
    
    SPI1_SetADC();      //set ADC Configuration
    LATDbits.LATD10 = 1; //START high -> Start Conversion

    //main while
    while(1)
    {
        DATA_counter++;
        SPI1_RREG();
    }
}

粗体 斜体

如上所述，我可以通过示波器看到有关SDI PIN的数据。 在此处输入图像描述 和另一个数据测试。 在此处输入图像描述

在示波器上可以看到的波形。 ADC模块可能以正确的方式工作。

但是...让我们看看Mplab Ide方面。 在此处输入图像描述 我无法获得正确的数据（SPI1BUF = 0x0001）。我试过较低的福音。但是结果没有什么不同。我缺少有参数吗？感谢您的帮助。

--------------------------------------------------------------------------------------- -----------------------------------------------------------

嗨，克雷格，我尝试了代码。

SPI1BUFL = 0x20; //send RREG Command //read 00h
while(SPI1STATLbits.SPITBF); // wait until the transmit buffer is empty

SPI1BUFL = 0x00; //set 1 byte
while(SPI1STATLbits.SPITBF); // wait until the transmit buffer is empty

uint8_t register1=0;
SPI1BUFL = 0x00; //send DUMMY data
while(!SPI1STATLbits.SPIRBF); //hang until data is received
register1 =  SPI1BUFL; //get data

结果没有差异。我录制了。

示波器： 在此处输入图像描述

IDE： 在此处输入图像描述

在此处输入图像描述

Answer 1

传输数据时，SPI每次都应清除SPI1BUFL。
因此，我尝试这样的代码。

    uint8_t SPI_EXCH(uint8_t data)
    {
       SPI1BUFL = data; // write to buffer for TX
       while(!SPI1STATLbits.SPIRBF); // wait for transfer to complete
       return SPI1BUFL; // read the received value
    }
    

每当您尝试进行SPI交换时，都会使用上面的功能。