Hi,
You are using AckI2C calls. I suppose you are trying to wait for the
acknowledge bit, but the micro does the job for you.
This function is intended to *generate* an ack bit, not wait for it.
Replace this functions with IdleI2C(), to make it wait until the bits are
sent.
This code will give you a staircase voltage in DAC0, at least in a MAX518.
The difference between the chips is minimal.
Rafael


#include "p18f252.h"
#include "i2c.h"


#define strobe LATCbits.LATC2
unsigned char contador;
unsigned char loop1;
unsigned char loop2;
unsigned char loop3;


void main(void)
{
TRISCbits.TRISC2 = 0;

TRISCbits.TRISC3 = 1;
TRISCbits.TRISC4 = 1;

contador=0xAA;
SSPADD = 0xFF;
OpenI2C(MASTER, SLEW_OFF);// Initialize I2C module

while(1)
{

strobe=1;
while( loop1<250 )
 loop1++;
strobe=0;

while( loop1<250 )
 loop1++;
while( loop1<250 )
 loop1++;
while( loop1<250 )
 loop1++;

// genera la condicion de start     (send start)
StartI2C();

// envia direccion                        (send chip address)
IdleI2C();
WriteI2C( 0x5E );

// envia comando                        (send command)
IdleI2C();
WriteI2C( 0x0 );

// envia datos                                (send data)
IdleI2C();
WriteI2C(contador);

// genera la condicion de stop            (send stop)
IdleI2C();
StopI2C();
IdleI2C();

  // espera un tiempo                     (wait)
loop1=0;
while( loop1<5 )
 {
 loop2=0;
 while( loop2<2 )
  {
  loop2++;
  }
 loop1++;
 }


contador++;
if (contador>254)
 contador=0;

}
}



<snip>

> Here is my source code:
> #include<p18f452.h>
> #include<i2c.h>
>
> file://function prototype
> void MAX517(unsigned int channel);
>
> void main(void){
>
>     char data_DAC;
>
>     file://init condition
>     TRISC = 0X1A;    file://Set SDA & SCL as 1. Activate I2C port
>
>     OpenI2C(MASTER, SLEW_ON);    file://Initialize I2C module
>     SSPADD = 9;    file://400KHz Baud clock (9) @16MHz
>
>     while(1){    file://Start condition
>         data_DAC = 0xFF;
>         MAX517(data_DAC);    file://Write data to I2C DAC
>         }//end of while
> }//end of main
>
> void MAX517(unsigned int channel){
> StartI2C();                 file://Start condition
> WriteI2C(0x58);        file://Address byte of DAC
> AckI2C();                 file://Ack
> WriteI2C(0x00);       file://Command byte
> AckI2C();                file://Ack
> WriteI2C(channel);  file://Output Data
> AckI2C();               file://Ack
> StopI2C();             file://Stop condition
> }//end of MAX517 funtion
>
> Nicholas
>

<snip>

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