Grounds on the uc32

[David Berger]

I am familiar with two labelled grounds on the chipkit uc32 and want to know if I can use any other pin as a general purpose ground to ground a button I'm trying to detect changes on.

Can I use the GND on the SPI to ground a button?  Is there some other pin that could be used as a ground?

Best,

David

[mskreen]

David Berger,

This question can be answered by a simple digital write test. All grounds on the board all route to the same place, therefore any ground you can find on the board, whether it be on the SPI pins or on the shield power connector will do the same thing. Straight from the Uc32's reference manual:  "The PIC32 microcontroller can source or sink a maximum of 18mA on all digital I/O pins... The maximum current that can be sourced(when high) or sunk(when low) across all I/O pins simultaneously is +/- 200mA". So, any digital pin that set to be low is a direct connection to ground as long as the current demand is less than 18mA, above that damage to the pin will result. If you ever have any questions about where a particular pin is routing to please take a look at the uC32's schematic. Oftentimes, either the schematic or reference manual will answer a question that you might have.

 

Mikel