Similar to the emonPi, the SleepyPi is an atmel powered board that sits on top of the Raspberry Pi. Also like emonPi, it requires a hacked version of AVRDude in order to trigger a GPIO pin to reset the AVR rather than the standard UART RST.
However, the SleepyPi differs from the emonPi slightly, because it uses pin 22 instead of pin 7 as its DTR pin.
What is the best way to get PIO support for this board?
I went ahead and started a PR for adding this support. It is not tested yet, but comments are appreciated. UPDATE: I tested this and it does work with a Sleepy Pi 2.