- Make the firmware accessible by soldering the 2x5 AVR ISCP male header to the USB Weather Board. NOTE: some boards might already have this header attached.
- Solder the 6x1 header to the BlueSMiRF connector on the USB Weather Board.
- Download, install, and start the FREE AVR Studio 4 Integrated Development Environment (IDE). The target AVR on the USB Weather Board is an ATmega8.
- Download the USB Weather Board firmware and create a new AVR Studio 4 project for your hacked firmware. For example, call your project 4Caster and paste the SparkFun Electronics firmware into the main 4Caster program window.
- Modify the firmware. The lines that I added for creating my 4Caster 1000 can be found here.