Floating 1.34V on RA3 of PIC16F684

Hello All; I am working with a PIC16F684 and for some reason, Pin RA4/AN3/T1G/OSC2/CLKOUT seems to ALWAYS show a floating 1.3V. Regardless of how I set the pin in the program, high or low, it still stays this way ALL THE TIME.

I am using the internal 31kHz oscilliator. Does this have anything to do with it? Or has anyone seen a similiar problem?? I am not a full-time programmer so my knowldge of PICs is adequate, but not expertise. Any recommendations?

I tested all other RA and RC pins and they all toggle 0V to Vdd when I tell them to. It is just this RA4 pin which is causing me greif.

I have attached a sample program in a .asm file which shows my errors.

Thanks All!

Have you checked the datasheet?? it might be a floating pin, requiring it to be pulled high or low..

Hi Cobra; Thanks for the response. Yes, I have checked the datasheet and I see no indication that this pin should be any different than any of the other RA or RC ports. I can just ground this pin in my final application circuit but I would like to use it if possible. I was thinking it is something I am missing in the .asm file but again, I am not sure at this point. Thanks again.

Steve

1. Put a LED and resistor on the pin to see if any current is present.
2. Use an analogue multimeter to read the pin.

It's RA4 right? not RA3 as stated in thread title. Try _INTRC_OSC_NOCLKOUT in config, as it looks like the clkout is on by default.

My guess would be that you have selected "101 = INTOSC oscillator: CLKOUT function on RA4/OSC2/CLKOUT pin, I/O function on RA5/OSC1/CLKIN" in your config settings.

Edit, looks like nickelflippr beat me to it.

Mike.

Off the top of my head RA4 is an open collector output. Take a look at the block diagram for PORTA

blueroomelectronics said:

Off the top of my head RA4 is an open collector output. Take a look at the block diagram for PORTA

Click to expand...

Not on the 684.

Mike.