Geps
Joined: 05 Jul 2010
Posts: 129
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| SSP Interrupt Not Always Getting Serviced |
 Posted: Sat Jul 23, 2011 7:33 am |
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Hi,
Compiler: 4.087
I'm trying to code a master/slave I2C based system on two PIC18F4520.
Using this topic as an example:
http://www.ccsinfo.com/forum/viewtopic.php?t=44686
I have the following code:
| Code: | #include <18f4520.h>
#fuses INTRC_IO, PUT, NOMCLR, NOWDT, NOPROTECT, NOLVP
#use delay(internal=8Mhz, clock=32Mhz)
#use rs232(baud=9600, xmit=PIN_C6, rcv=PIN_C7, ERRORS)
#use i2c(Master, sda=PIN_C4, scl=PIN_C3)
#define SLAVE1_WRT_ADDR 0x12
#define SLAVE1_READ_ADDR 0x13
//====================================
void main()
{
int8 data1, data2;
delay_ms(1000);
printf("Starting!");
while(TRUE)
{
i2c_start();
i2c_write(SLAVE1_WRT_ADDR);
delay_us(100);
i2c_write(3);
delay_us(100);
i2c_write(3);
delay_us(100);
i2c_write(3);
delay_us(100);
i2c_write(3);
delay_us(100);
i2c_write(3);
delay_us(100);
i2c_stop();
delay_ms(50);
}
}
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Slave code:
| Code: | #include <18f4520.h>
#fuses INTRC_IO, NOPUT, NOMCLR, NOWDT, NOLVP
#use delay(internal=8Mhz, clock=32Mhz)
#use i2c(SLAVE, SDA=PIN_C4, SCL=PIN_C3, address=0x12)
#define REDLED PIN_C0
#define SCL PIN_C3
int8 incoming =0;
int1 ProcessDataFlag = 0;
#INT_SSP
void ssp_interrupt() {
int8 state= 0;
output_high(REDLED);
state = i2c_isr_state();
if(state < 0x80) // Master is sending data
{
incoming = i2c_read();
}
if(state >= 0x80) // Master is requesting data from slave
{
}
output_low(REDLED);
}
//======================================
void main ()
{
delay_ms(500);
output_high(PIN_A7);
enable_interrupts(INT_SSP);
enable_interrupts(GLOBAL);
while(TRUE)
{ }
}
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The problem I'm getting is that the interrupt isn't getting serviced on receipt of every byte - only the first two bytes.
Where am I going wrong?
Cheers, |
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