v2 board problems

[Dakta]

I've come here in the hope to shed light on some issues i've been having with my 'v2' development board.

I don't know if it's issues or inexperience tbh, but let's see.

I didn't have the original adapter to hand and it's a while since I used it so I sued a spare 12v adapter. Programming wouldn't work, so I used my willem programmer instead. Was a bit of a hassle and my programmer doesn't support the pic 16f873a I was wanting to toy with, so I tried to fix the programming issue.

The issue was it wouldn't program, would fail at mostly the beginning of the writing process, I suspected this was a voltage issue, the board was detected fine etc.

Anyway I stripped a pc power supply and took a 12 feed of that and got it to get a bit further, so eventually I managed to get a 15v supply working to the board, and now she programs and verifies fine. I thought I'd managed it!


But I still seem to have a problem, if I program the 16f84a with a prograsm to flash the led, it works, whether I configure it to XT or RC.

However - I cannot get the 16f873a to work - at all. It's a brand new chip and I've tried two. I've even tried different programs, you send to the board, it programs it and verifies it, then nothing. The board just sits there doing nothing. You press reset nothing happens, if you press the port buttons they light up but thats all you can get, it's like the chips been removed from it but in fact it hasn't.

Any ideas, is it likely to be a coding issue? I've tried both RC and XT to no avail.


cheers
Kris

[Steve]

You will need to turn the ADC module off in that chip to use PORTA as digital i/o.

Other things that come to mind are settings within the configuration word: the watchdog timer, DEBUG, and an appropriate clock setting (with appropriate delay timing).

[Dakta]

You will need to turn the ADC module off in that chip to use PORTA as digital i/o.

Other things that come to mind are settings within the configuration word: the watchdog timer, DEBUG, and an appropriate clock setting (with appropriate delay timing).

cheers, just been playing with it now:

Apart from a header (which has analogue inputs on porta for 1,2,3 and 5 - in particular i'm interested in the onboard potentiometer for playing with this chip) I also have:

ROUTINE MOVLW B'11111111'
MOVWF PORTB
CALL DELAY1

MOVLW B'00000000'
MOVWF PORTB
CALL DELAY1
CALL ROUTINE

Just a simple flash routine with 'DELAY1' being a one second delay calculated with picloopz for the 3.2768mhz crystal. Im still on the learning curve but I'm running configuration bits of '3FF9' in code, (XT, Watchdog Timer Disabled, Code Protection OFF etc). I also adjust the PPP to match these before programming.

The result is all portb led's light up (except B3), no flashing? If you press the button on b3, all portb lgihts reverse (b3 lights up, all others stop)

That said, this is a considerable success because every other project i've sent to it, even projects which simulate (oshonsoft, Real pic simulator etc) just don't get a reaction out of the board. It just sits there, no led's on, nothing. The led's do come on if you press the buttons.

[Steve]

B3 is the LVP pin - you will need to turn this off in the config bit.

As all lights are on, this points to the delay being far too long.

[Dakta]

Aha! Progress!

I think I'm going to have to research this low voltage programming issue, as with it I can't get the led's to light up, and without it some of my bigger programs won't verify.

Clearly I could do to understand whats happening and why a bit better. You did get my flasher program working though! (thankyou)

So the final question is - how can I avoid programming errors with low voltage programming disabled?

Is my power supply still inadequate perhaps?