Programming

As we already mentioned, the kit for this project includes a pre-programmed microcontroller. There is no reason why you shouldn’t change the program and re-program the chip, after all that’s half the fun of hacking. Once any changes have been made or new code has been created using an editor program, it will need to be converted into machine code using a compiler. The resulting hex file can then be transferred to the microcontroller’s flash memory using a program such as AVRDUDE. Here you will need an extra bit of hardware. In addition to a programmer such as the Atmel AVR-ISP MK2 you will need a programming adapter with an IC socket; it can be easily built using a small square of perf board (Figure 2). This handy bit of hardware will also be useful in the future for reprogramming the microcontroller if you need to make changes. Another aspect of microcontroller programming is setting the internal fuses which are used to configure the microcontroller (i.e. to enable operation with the internal oscillator for example). This project just uses the default settings so it is not necessary to worry about fuse settings at the moment.