Using Program Out pin as output


Senior Member
I am planning a project that uses an AXE131Y display in its standard serial input mode but can also operate as a Kitchen Timer (hours and minutes). To achieve the TImer mode needs 2 digital inputs (one an interrupt) and 2 digital outputs to the built-in 18M2.

As it stands, the AXE131Y has 3 available I/Os, C.0, C.1 and C.2. I need 1 more. I could use the program input C.4 as an input with DISCONNECT but it seems it would be marginally simpler to use the program out C.3 as an output.

Am I right in thinking that DISCONNECT is not necessary to use the prog out pin? And I just need to be sure that nothing overloads the prog pin during programming? Are there any other points I should consider?



Senior Member
There should be no issues with using C.3 ( Download Serial Out ) as an output on the 18M2 of the AXE131, and, no, DISCONNECT is not needed to do that. Just use HIGH, LOW, PULSOUT, SEROUT and other commands as if a normal output pin.

The only thing to consider is that SERTXD and DEBUG won't necessarily always work unless the pin is set LOW first, and those may interfere with whatever's being driven by that output.