Is a very light implementation of Risc-V I, with an RTC for 1mS interruptone video interface with rectangle draw acceleration and four PIO connected to the cartridge.
The app draw an animation of a 3D triangle and monotor the four ports of the cartridge.
https://github.com/dev-board-tech/hdl-core-riscv-lite-v2
https://github.com/dev-board-tech/hdl-core-common/tree/master/io-atmega
In order to open the app you need to download the FreedomStudio ( this is the last version that is completely packaged and support native eclipse projects ):