This post provides the external interrupt code for PIC12F675 microcontroller (e-g when you need to control servo motor which has position encoder, with your PIC microcontroller).
As we know, PIC12F675 microcontroller has one GP2/INT pin, which can be used to service external interrupts. This code is written in C language using MPLAB with HI-TECH C compiler. You can download this code from the ‘Downloads‘ section at the bottom of this page.
It is assumed that you know how to blink an LED with PIC12F675 microcontroller. If you don’t then please read this page first, before proceeding with this article.
The result of simulating the code in Proteus is shown below.
In the above circuit, normally a low value is present on the GP2/INT pin because of the pull down resistor. But when push button is pressed then a low to high pulse on the GP2/INT pin generates the interrupt. And code is written in such a way that whenever interrupt is generated then GP5 pin is toggled.
The code for the main function is shown below.
External interrupt code for PIC12F675 was compiled in MPLAB v8.85 with HI-TECH C v9.83 compiler and simulation was made in Proteus v7.10. To download code and Proteus simulation click here.
For more detail: PIC12F675 external interrupt code and Proteus simulation