PIC16f1684 initialization help...PORTC works but not PORTA

[TwistedE]

Hi everyone,

I have a pretty simple project at hand which uses a pic16f684 and L293D motor driver to run a 12v stepper motor. Everything worked fine, motor moved, etc. when the PIC talked to the motor driver via the circuit (jpeg attachment). I'm always using the internal clock so does RA5/OSC1/CLKIN have to be grounded?

I decided to change the output ports to RA0, 1, 2 and RC0 for easier wire routing. My new code (very similar to previous one) compiles but doesn't work. None of the Port A ports are outputting any voltage at all ( i checked manually with a voltmeter ). I think I'm not initializing TRISA properly or something because everything with PORT C pins works fine.

program Prog1

DIM x as byte
DIM y as byte

 main:


 ANSEL = 0
 TRISC = $00
 TRISA = $00

 
 PORTA = $20       'Turns on a yellow led at RA5 quickly for initial testing
 PORTC = 0

 x = 0
 y = 0

delay_ms(1) ' delay of 1s



PORTA = 0
 while(1)
 
         while (x < 15)
 
               Gosub Forward
               x = x + 1
               delay_ms(2)
      
         wend
         
         PORTC = 0
         PORTA = 0
         delay_ms(500)
         
         while (y < 15)

               Gosub Reverse
               y = y + 1
               delay_ms(2)

         wend
         
         PORTC = 0
         PORTA = 0
         delay_ms(500)

         x = 0
         y = 0
 wend

 Forward:
      PORTA = $05       'STEP 1
      PORTC = $10
       delay_ms(10)
      PORTA = $06       'STEP 2
      PORTC = $10
       delay_ms(10)
      PORTA = $02       'STEP 3
      PORTC = $11
       delay_ms(10)
      PORTA = $01       'STEP 4
      PORTC = $11
       delay_ms(10)
      return

 Reverse:
      PORTA = $01       'STEP 4
      PORTC = $21
       delay_ms(10)
      PORTA = $02       'STEP 3
      PORTC = $21
       delay_ms(10)
      PORTA = $06       'STEP 2
      PORTC = $20
       delay_ms(10)
      PORTA = $05       'STEP 1
      PORTC = $20
       delay_ms(10)
       
      return
      
      
 end.

 

[Pommie]

Try turning off the comparators with CMCON=7.

Mike.