nullstalgia

Software prerequisites

You need to have avrdude and avr-gcc installed on a Raspberry Pi.

Flashing USBaspLoader

These two sites were very helpful in wiring up the ATmega328P to the GPIO pins on the Raspberry Pi:

• http://ozzmaker.com/program-avr-using-raspberry-pi-gpio/
• https://learn.adafruit.com/program-an-avr-or-arduino-using-raspberry-pi-gpio-pins/configuration

nullstalgia

#include <avr/sleep.h>
#include <avr/wdt.h>

volatile bool wdtFired;

// watchdog interrupt
ISR (WDT_vect)
{
   wdt_disable();  // disable watchdog
   wdtFired = true;