The current CubeSatSim hardware is in the v1.2 folder https://github.com/alanbjohnston/CubeSatSim/tree/master/hardware/v1.2.  The folder contains gerbers, schematics, and images of the Main, Battery, and STEM Payload boards.

Note: the main differences between the v1.2 and v1.1 hardware is a USB-C charging connector instead of the micro USB.

For information on building the boards, see https://cubesatsim.org/wiki.

Gerber files on PCBWay: https://www.pcbway.com/project/shareproject/AMSAT_CubeSat_Simulator.html

Older beta versions of the hardware are in the other folders and should not be used.
