If you do not want to use the firmware installed by FarmBot OS, you can still install custom firmware using the standard Arduino IDE with the steps below.

1. Download and install the Arduino IDE onto your computer.
2. Download and unzip the latest FarmBot Arduino Firmware.
3. In the firmware folder you just unzipped, go to the src sub-folder and open up src with the Arduino IDE. Note: this file is blank, but there are many other file tabs that should be automatically opened as well.
4. Connect your Arduino to your computer with a USB cable.
5. From the IDE, click Tools > Board, and then select Arduino Mega 2560.
6. Now click File > Upload. This will flash the firmware onto your Arduino.