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Help: Use Aduc845 SPI interface to drive MAX7221

Question asked by giveyou on Nov 7, 2013
Latest reply on Nov 11, 2013 by ABuda

Hello, I am working on an embedded project involving the ADuC845 micro  and the MAX7221. I am using the Keil development tools as  my IDE for this project. The interface between the ADuC845 and the  MAX7221 is SPI. The ADuC845 is configured as the master and the MAX7221  is the slave.

When I test the AduC845 SPI interrupt ,It can work well. the code as below:

 

#include <Aduc845.h>
sbit LED = P3^6;

void InitPLL()
{
    CFG845 = 0x81;        // enable extended sp, XRAM enable
    PLLCON = 0x00;        // Fosc = 12.582912MHz
    while (!(PLLCON & 0x40));
}

void InitSPI()
{
    SPE  = 1;
    SPIM = 1;
    CPOL = 0;
    CPHA = 0;
    SPR1 = 1;
    SPR0 = 1;
    IEIP2=0x11;
    EA = 1;
}

void main(void)
{
    unsigned int i;
    InitPLL();
    InitSPI();
    LED ^= 1;
    
    while(1)
    {
        SPIDAT =  0x01;
        for(i=60000;i>0;i--);
        for(i=60000;i>0;i--);
        for(i=60000;i>0;i--);
        for(i=60000;i>0;i--);
        for(i=60000;i>0;i--);
        for(i=60000;i>0;i--);
        for(i=60000;i>0;i--);
        
    }
    
}


void SPI_I2C_ISR() interrupt 7 //SPI,IIC中断 
{
    if(ISPI)
    {
        LED ^= 1;
        ISPI = 0;
    }
} 

 

 

When I use the code to drive MAX7221,It can't work. the code as below:

 

 

#include <Aduc845.h>
#include <intrins.h>

sbit nCS = P2^7;    // CS for Max7221

sbit LED = P3^6;

// 0-F,P,-,No, without dot
code unsigned char seg7[19]={0x7E,0x30,0x6D,0x79,0x33,0x5B,0x5F,0x70,0x7F,0x7B,0x77,0x1F,0x4E,0x3D,0x4F,0x47,0x67,0x01,0x00};
void InitPLL()
{
    CFG845 = 0x81;        // enable extended sp, XRAM enable
    PLLCON = 0x00;        // Fosc = 12.582912MHz
    while (!(PLLCON & 0x40));
}


void InitSPI()
{
    SPE  = 1;
    SPIM = 1;
    CPOL = 0;
    CPHA = 0;
    SPR1 = 1;
    SPR0 = 1;
    IEIP2=0x11;
    EA = 1;
}
void Write_Max7221(unsigned char dat)
{
    nCS = 0;
    SPIDAT =  dat;
    nCS = 1;
}
void InitMax7221()
{
    nCS = 0;
    Write_Max7221(0x09);        // decode mode = no decode 
    Write_Max7221(0x00);        // No decode for digits 7-0    
    nCS = 1;
    nCS = 0;
    Write_Max7221(0x0A);        // intensity = 8/16 
    Write_Max7221(0x07);        //     
    nCS = 1;
    nCS = 0;
    Write_Max7221(0x0B);        // scan limit =digit 0-3 
    Write_Max7221(0x03);        //     
    nCS = 1;
    nCS = 0;
    Write_Max7221(0x0C);        // Shutdown Mode = Normal Operation 
    Write_Max7221(0x01);        //     
    nCS = 1;
}

 void main(void)
{
    unsigned int i;
    unsigned char j;
    InitPLL();
    InitSPI();
   InitMax7221();
    LED ^= 1;
    j=0;
    
    while(1)
    {
        Write_Max7221(1);
        Write_Max7221(seg7[j]);
        Write_Max7221(2);
        Write_Max7221(seg7[j]);
        Write_Max7221(3);
        Write_Max7221(seg7[j]);
        Write_Max7221(4);
        Write_Max7221(seg7[j]);
        j++;
        if(j>18)    j=0;

        for(i=60000;i>0;i--);
        for(i=60000;i>0;i--);
        for(i=60000;i>0;i--);
        for(i=60000;i>0;i--);
        for(i=60000;i>0;i--);
        for(i=60000;i>0;i--);
        for(i=60000;i>0;i--);
        
    }
    
}


void SPI_I2C_ISR() interrupt 7 //SPI,IIC中断 
{
    if(ISPI)
    {
        LED ^= 1;
        ISPI = 0;
    }
}

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