CAN CONTROLLER MCP2515 & PIC16F877A SPI interface using

[jennifer]

Hi
i am not getting result while MCP2515 & PIC 16F877A SPI Interface in PICC, Problem in the program........we are trying to write a value to CAN Register and read that value to output in port d in pic 16f877a

here the codes:
#define MCP2515_CS PIN_B5
#define MCP2515_RESET_PIN PIN_B0
#define READCMD 0x03
#define WRITECMD 0x02
#include<16F877A.h>
#include<PIC16F877A.h>
#include<MCP2515.h>
int reg;
int outvalue;

void RESETMCP2515()
{
output_high(MCP2515_CS);
output_low(MCP2515_RESET_PIN);
delay_us(10);
output_high(MCP2515_RESET_PIN);
}

int READREG(int regaddres)
{
output_low(MCP2515_CS);
spi_write(READCMD);
spi_write(regaddres);
clear_BF();
reg=spi_read();
output_high(MCP2515_CS);
return(reg);
}

void WRITEREG(int regaddres,int regvalue)
{
output_low(MCP2515_CS);
spi_write(WRITECMD);
spi_write(regaddres);
spi_write(regvalue);
output_high(MCP2515_CS);
delay_us(10);
}

void MAIN()
{
setup_spi(SPI_MASTER|SPI_L_TO_H|SPI_CLK_DIV_4);
WRITEREG(CANCTRL,0x80); //set to config mode
WRITEREG(CANCTRL, 0x00); //reset to normal mode
trisd=0x00;
trisc=0x10;
WRITEREG(TXB1D0,0X0d);
reg=READREG(TXB1D0);
portd=reg;

}

[PCM programmer]

Did you get that code from this thread ?
http://www.ccsinfo.com/forum/viewtopic.php?t=18539
Your code has many errors. You need to look closely at the code
in the link above. Read all the posts. It explains how to correctly
setup the SPI mode for the MCP2515. Also look closely at how
you are using the spi_read() function. Note that the code in the
link uses a parameter of 0 with that function. That parameter
is required if you want the PIC to generate the SPI clock, and
you do need to generate it. Follow the code in that thread.

[jennifer]

I tried to modify my code according to ur instructions..yet v didnt get the output..the modified code is given below..pls help me..



#define MCP2515_CS PIN_B5
#define MCP2515_RESET_PIN PIN_B0
#define READCMD 0x03
#define WRITECMD 0x02
#include<16F877A.h>
#include<PIC16F877A.h>
#include<MCP2515.h>
int reg;


void RESETMCP2515()
{
output_high(MCP2515_CS);
output_low(MCP2515_RESET_PIN);
delay_us(10);
output_high(MCP2515_RESET_PIN);
}

int READREG(int regaddres)
{
output_low(MCP2515_CS);
spi_write(READCMD);
spi_write(regaddres);
spi_read(0);
reg=spi_read();
output_high(MCP2515_CS);
return(reg);
}

void WRITEREG(int regaddres,int regvalue)
{
output_low(MCP2515_CS);
spi_write(WRITECMD);
spi_write(regaddres);
spi_write(regvalue);
output_high(MCP2515_CS);
delay_us(10);
}

void CONFIGMCP2515()
{
int cnfr1 = 0x90;
int cnfr2 = 0x92;
int cnfr3 = 0x84;

WRITEREG(CANCTRL, 0x80); //set to config mode
WRITEREG(CNF1, cnfr1);
WRITEREG(CNF2, cnfr2);
WRITEREG(CNF3, cnfr3);
WRITEREG(CANCTRL, 0x00); //reset to normal mode
}

void MAIN()
{
trisd=0x00;
setup_spi(SPI_MASTER|SPI_H_TO_L |SPI_XMIT_L_TO_H| SPI_CLK_DIV_4 );
RESETMCP2515();


CONFIGMCP2515();
WRITEREG(TXB2D2,0XF0);
reg=READREG(TXB2D2);
portd=reg;

}

[PCM programmer]

But you didn't pay attention to the code in that link.
Here's one routine from that link:

[JENNIFER]

Thank you for your help.We got the result .......