Drawing a blank on trigger pin polarity

[LinkMTech]

That will work just fine Tony.
The one A/D input can be used to monitor and trigger to many levels of the input range within tolerance, but your application is a snap with only three states: Max A/D, Mid A/D and Min A/D.

Here's an example using a three state momentary switch:



Just make sure the switching value being monitored will not damage your uC.

Now a simple routine can monitor and do what you need:

SW_1  VAR BYTE    ' A/D setup with 8bit

ADCIN 0, SW_1     ' Assuming PIC Vdd is 5V and using A/D input 0

SELECT CASE SW_1
   CASE IS < 26   ' Input less than 0.50V
      ' Do something
   CASE IS < 135  ' Input less than 2.64V
      ' Do something else or nothing at all
   CASE IS > 135  ' Input more than 2.64V
      ' Do something
END SELECT