PIC18f4220

[BUSHRATARIQ]

hey i am a beginner in embedded programming. i am trying to make a master slave spi link between two pics, pic18f4220. but i am facing alot of problem.
i am configuring everything fine but there is nothing on my SCK pin of master pic. also there is nothing on my SDO of master pic. and another problem i am facing is that i have connected an led to port b configured as output port. to blink at the start and end of code. its blinking is not visible unless i put a probe on some other pin of port b.
i dont understand why.
Can anyone please help!

 

[Wp100]

Hi,

You need to post your program code for both master and slave plus the circuit diagram, otherwise its difficult to see where you have gone wrong

 

[atferrari]

Post the inizialization code as well.

 

[BUSHRATARIQ]

hey
i am trying to configure only master pic first and separately. the code i am using is

#include<p18f4220.h>
#include<spi.h>
#pragma config WDT=OFF

void main()

{
unsigned char a,m;

TRISB=0;
PORTB=0;

TRISA=0;
PORTA=0x03;

m=0xFF;

PORTAbits.RA0=1;
SSPCON1bits.SSPEN=1;
SSPCON1bits.SSPM0=0;
SSPCON1bits.SSPM1=0;
SSPCON1bits.SSPM2=0;
SSPCON1bits.SSPM3=0;
SSPCON1bits.SSPOV=0;
SSPCON1bits.WCOL=0;

TRISC=0;
SSPCON1bits.CKP=0;
SSPSTATbits.CKE=0;
SSPSTATbits.SMP=0;

while(1)
{
PORTB=0xFF;
PORTAbits.RA0=0;
a=1000;
while(a--);
SSPBUF=m;
PORTAbits.RA0=1;
PORTB=0;

a=1000;
while(a--);

}

The problem with this code is that i dont get anything on the SDO pin and SCK.

 

[Ian Rogers]

According to the datasheet.. You have to set all the relevant SSP module settings BEFORE you enable.

Set your SSPCON bits and then enable SSPEN.

Wrong info deleted