Adding external switch for emergency stop and feed override

Dear LinuxCNC User,

I have bare minimum code of .ini and .hal file that perfectly working for single axis linear stage. Now, I want to add two switches one for emergency stop and another for feed override. I am planning to use pin 0 for emergency stop and pin 1 for feed override of Mesa 7i95 board.

Kindly provide the necessary pieces of code that need to be added in .hal and .ini file. explain the logic of the connection because I am not an expert of editing the .hal file.

The wiring I am planning for these switches are following..

either 0 or 5 volt to pin 1 using external DC power supply (I don't have switch currently but will buy it soon)

Continuous Analog voltage from 0-5 volt at pin 2 using another DC Power supply

GND, 0 volt at pin 3, because it is common ground for pin 0 and pin 1.

I am using linuxcnc 2.9.2


Thanks.