Initializing ad7302 with pic18f97j60 (in MikroC)

[Bluestar88]

I am using PIC 18 series(pic18f97j60) micro controller in my project. I am interfacing this microcontroller with DAC-ad7302. I used PORTF for D7-0 and PORTG For WR, A/B, CS, PD, CLR and LDAC.

I Wrote below code

void main() {  
     TRISF = 0 ;             // set PORTF as output
        

        TRISG = 0 ;             // set PORTG as output           

  while(1)
                  {

                  PORTG.RG3=1;
                   PORTG.RG4=0;
                   PORTG.RG0=0;
                  // PORTF=UART1_Read();
                  PORTF=0xff;
                   PORTG.RG0=1;
                   PORTG.RG7=0;
}
}

, But I dont have any output in pin 18 of ad7302. It is zero all of the time.:shock:


Please help me.

 

[KlausST]

Hi,

I didn´t go deeply through your code.

Please divide into
* initialisation (before the "while")
* communication (within the "while loop")
(usually within the "while loop" ...every pin that is SET ... wil become CLEARED and vice versa.
but in your code RG3 is SET but never CLEARED.. and the next loop run it is a gain SET...
with other pins it´s the same.)

I recommend that your code stricly follows the diagram in the datssheet.

Some additonal hints:
* define useful signal names instead of the "PORTG.RG3" (No one knows what "RG3" is .. without a schematic.)
* RG5 and RG6 are never initialized.

Klaus

 

[Garyl]

you don't have any "wait" instruction in your loop

while(1)
                  {

                  PORTG.RG3=1;
                   PORTG.RG4=0;
                   PORTG.RG0=0;
                  // PORTF=UART1_Read();
                  PORTF=0xff;
                   PORTG.RG0=1;
                   PORTG.RG7=0;
}

and you're doing:

PORTG.RG0=0;
and later:

PORTG.RG0=1;
which is executed very, very fast.
Is this intented?



Also, don't you need to disable comparators and analogue pins for this pic?