This add-on board’s main feature is to add analog inputs and L2/R2 “trigger/shoulder” buttons. This kit will require adding parts to your existing Freeplay CM3 which may involve soldering or shell modifications. It will also require you to install and edit software on your Freeplay CM3. It is intended for builders that have experience soldering and are okay with logging into Linux and making changes there. You can choose to purchase it with or without a fan. The fan is a special one that pulls air through the hole in the circuit board and then blows it out the side across the fins of the heat sink on your RPi Compute Module 3’s CPU.
This add-on board adds 3 new buttons (likely mapped as L2, R2, and hotkey). It also adds 4 analog chips (via i2c) that can be used by the Freeplay joystick driver for something such as a PSP1000 analog stick. 2 analog inputs are enough for a single analog stick, but you will have 4 analog chips installed and at your disposal. We have seen at least one builder that has added dual analog sticks using the 4 analog inputs. You could also experiment with adding other features. Note that the green and red wire pair shown in the photos are coming from a PSP1000 analog stick we have installed for testing.
Note: The photos shown are only meant as usage examples. The product delivered may differ.