Can't keep a pin low

[bartman]

Hmmm, can there be a fourth choice?

I swapped PICs with no change
I've triple checked all the connections on the breadboard

That leaves a code problem.

Here is the first part of that:

@ DEVICE pic12F629, INTRC_OSC_NOCLKOUT ' Internal Oscillator
@ DEVICE pic12F629, WDT_ON ' Enable watch dog timer
@ DEVICE pic12F629, PWRT_ON ' Enable power up timer
@ DEVICE pic12F629, MCLR_ON ' Enable MCLR pin

Define OSCCAL_1K 1 ' Oscillator calibration

TRISIO = %11101011 ' turn all I/O to input except GPIO.2 and GPIO.4

CMCON = 7 ' Disable analog comparator

Which is working for all other input and output.

As far as I can tell there is no command that is not allowed. It is all basic stuff like driving a buzzer based on buttons pressed - really nothing fancy. A single input on any of the other lines that does nothing but make a beep seems to be flipping that pin - and that buzzer is on port 2.

I'll keep going through the code.

Thanks.

Bart

I just tried something simple and discovered that when my port 2 goes HIGH, port 4 is going HIGH at the same time, but it will not switch back when port 2 goes LOW again.

Does that suggest anything?