RE: I2C line following sensor - can't read

jsummerour — Fri, 09 Jul 2010 10:39:56 GMT

Here is the PIC code we use in the Serializer, where address is 0x50:

#use I2C(master, sda=PIN_c4, scl=PIN_c3,slow)

...

i2c_start(); // restart condition
i2c_write(ADDRESS + 1);
value = i2c_read(0);
i2c_stop();

Best Regards,

I2C line following sensor - can't read

johnb — Fri, 11 Jun 2010 04:43:01 GMT

Hello I have been trying for 2 days to read the sensor but without success.
I'm using a pic18f248 with 1.8k pull up on sda & scl and the c18 compiler

here is my code maybe you guys can find anything wrong ?
I don't know if my I2C_read routine is correct.
Maybe my initialization isn't correct ? I've read many topics on internet and there was sometimes " #pragma config BOR = ON " but I didn't see anything about that on the 18f248 datasheet.

#include
#pragma config OSC=HS
#pragma config WDT=OFF
#pragma config LVP=OFF

void I2C_idle(void)
{
int boucle;

while(boucle == 0)
{
if((SSPCON2bits.ACKEN == 0) && (SSPCON2bits.SEN == 0) && (SSPCON2bits.RSEN == 0) && (SSPCON2bits.PEN == 0) && (SSPCON2bits.RCEN == 0) && (SSPSTATbits.R_W == 0))
boucle=1;
}
}

void I2C_start(void)
{
I2C_idle();
SSPCON2bits.SEN = 1;
}

void I2C_write(char donnee)
{
I2C_idle();
SSPBUF = donnee;
}

void Ack_slave_master(void)
{
I2C_idle();
while(SSPCON2bits.ACKSTAT==1);

}

void Repeated_start(void)
{
I2C_idle();
SSPCON2bits.RSEN = 1;
}

void I2C_read(void)
{
I2C_idle();
SSPCON2bits.RCEN=1;
while(SSPCON2bits.RCEN==1);
}

void Ack_master_slave(void)
{
I2C_idle();
SSPCON2bits.ACKDT = 0;
SSPCON2bits.ACKEN = 1;
}

void I2C_NOACK(void)
{
I2C_idle();
SSPCON2bits.ACKDT = 1;
SSPCON2bits.ACKEN = 1;
}

void I2C_stop(void)
{
I2C_idle();
SSPCON2bits.PEN = 1;
}

void pause(void)
{
unsigned int time = 0;

while(time < 10000)
time++;
}

void main(void)
{
unsigned char test;
SSPSTATbits.SMP = 1;
SSPSTATbits.CKE = 0;
SSPADD = 0x31; //master mode
SSPCON1 = 0x28; //SCL ~100k
TRISB = 0x00;
TRISC = 0x18;
I2C_start();
I2C_write(0x50);
I2C_read();
I2C_stop();
PORTB=SSPBUF; //display the result
while(1);

}

with this code the only thing displayed is the value inside write

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RE: I2C line following sensor - can't read

I2C line following sensor - can't read