LogStick Project #4

This project from Rod Crawford's LogStick Blog is the fourth of a series of examples that show how to get started using the RealView Microcontroller Development Kit for ARM devices.

This project is the fully working button interrupt example.

Pin 1 of GPIO 0 is used to trigger external interrupt 0. The external interrupt is set to invoke the interrupt service routine in slot0 of the Vectored Interrupt Controller. This routine increments a counter showing how many times it has been invoked. The interrupt is triggered on edge to enure that one interrupt is taken for one button press.

The foreground program waggles pin 1 of GPIO 1 up an down to provide visual representation that the program is running and all is well.

When run using the simulation environment in the RealView Microcontroller Development Kit a button is added to the toolbox which can be used to take Pin 1 low and trigger the interrupt.