LB6 does not light.

[adamscybot]

Ive just flashed this program:

ORG 0 ; Reset vector
GOTO 5 ; Goto start of program
ORG 4 ; Interrupt vector
GOTO 5 ; Goto start of program
ORG 5 ; Start of program memory
CLRF 6 ; set all Port B pins to logic 0
BSF 3,5 ; instruct program that a Page 1
; command comes next
CLRF 6 ; set all Port B pins as outputs
BCF 3,5 ; instruct program that a Page 0
; command comes next
BSF 6,0 ; set Port B pin 0 to logic 1
BSF 6,1 ; set Port B pin 1 to logic 1
BSF 6,2 ; set Port B pin 2 to logic 1
BSF 6,3 ; set Port B pin 3 to logic 1
BSF 6,4 ; set Port B pin 4 to logic 1
BSF 6,5 ; set Port B pin 5 to logic 1
BSF 6,6 ; set Port B pin 6 to logic 1
BSF 6,7 ; set Port B pin 7 to logic 1
END ; final statement

LB6 does not light? Why is this?!

Adam

[Ian]

Hi UKWeb,

I tried it here and it worked fine on an 877A with LB6 lighting up as expected.

I can't think of anything off hand that would stop LB6 lighting up from a code point of view. Next obvious step then is looking at the hardware.

What board are you using? And with what chip?
Is there anything on pin B6 on that device that could block IO (e.g. analogue ports).

If it is an E-blocks board with a LED board, have you tried any other boards e.g. other LED boards, Switch boards etc. to check if you can get a signal on the LB6 to see if that pin is working or not.

[adamscybot]

Hi UKWeb,

Who's UKWeb? lol.

Im using a PIC16F88 chip on the PICMicro Development Board V3. The light itself isnt faulty, as when I press switch SB6 to allow current to pass LB6 does light.

I have also just noticed something. When I looked closly, each light lights up in turn - even LB6!. One by one they switch on. However, LB6 only turns on for a fraction of a second and quickly goes off as LB7 lights.

I have just madea program that makes ONLY LB6 light - and LB6 lights perfectly and stays on as expected. This problem is very odd.

I am not using any e-blocks.

[Steve]

This sounds like there is a short between B6 and (probably) B7. It is likely to be on the dev board itself, but could possibly be the chip. Have you tried another chip?

Assuming it is the board, make sure all the jumpers are aligned with their metal connections horizontal (on the most recent HP488's, connecting the "LCD_LVP" jumpers incorrectly could cause this problem).

If you still have the problem and the board is still under warranty, send it back to us and we'll replace it if there is a problem.

If it is no longer under warranty, there are some places to look for obvious shorts. On the underside of the board, pay attention to the 2 40-way headers and the DIL sockets for the PICmicros.

I hope this is helpful.

[Ian]

Who's UKWeb? lol.

Ooops. Senile dementia creeping up on me there.