I’ve been on mission lately to design a handheld bluetooth game controller. I’ve made a prototype in the past but, it never was really usable as a gaming device. Although the concept worked well the form factor was not quite there.
Well after a few months of tinkering and several designs I finally have one!
The design is based around the Atmega 328 running the Arduino bootloader. There is a RN42-HID bluetooth module that allows serial communication between it and the microprocessor.
I wanted the device to be fully hackable so I designed it with headers for both the bluetooth module and the Atmega 328 chip. I can reprogram the bluetooth module to run HID keyboard or mouse (or combined), it can iterate as a gamepad, or it can reconfigured to run serial protocol and iterate as a virtual com port.
For more detail: Arduino Based Handheld Bluetooth Game Controller