Ra4 not working

[i2c2k]

Hi!

I use the pin RA4 of a PIC16F876A to drive a LED, but the LED never flashes although I didn't forget anything (set TRIS register etc., I tried several chips).
By the way I use RA0/AN0 as an analog input.
Has anybody experienced the problem already and can tell me, how I can solve it?

cya
i2c2k[/code]

 

[Nigel Goodwin]

Hi!

I use the pin RA4 of a PIC16F876A to drive a LED, but the LED never flashes although I didn't forget anything (set TRIS register etc., I tried several chips).
By the way I use RA0/AN0 as an analog input.
Has anybody experienced the problem already and can tell me, how I can solve it?
[/code]

RA4 is usually an open-collector output (see the datasheets), so you can only sink current, not source it.

 

[RonH]

Put a pullup resistor on it and you'll be set.

Ron