Kerry Wong built a DIY constant current/constant power electronic load. One of the features a lot of commercial electronic loads has in common is the ability to sink constant power. Constant power would come in handy when measuring battery capacities (Wh) or testing power supplies for instance. To accommodate this, she decided to use an Arduino (ATmega328p) microcontroller.
This video demonstrates some features of a DIY electronic load I built. This electronic load can be used in constant current or constant power mode and can sink more than 200W of power.