[Mori] wanted to use his keyboard and mouse to play his favorite games on the PS4, so he made a decision to customize his Dualshock4 controller to feed it custom-made input signals.
In the heart of this build is an STM32F407 discovery board, which is connected to a USB hub. To do this hack, [Mori] tore open the Dualshock4 controller to find the PCB traces coming from the sticks and buttons. He then used the STM32F407 and 2 digital to Analog Converters (DACs) to create similar signals. regrettably for us, [Mori] only released the schematics but not the firmware. Our guess is that he had to configure the microcontroller as a USB host, enumerate the mouse/keyboard, parse the HID reports and feed the controller the corresponding inputs.
We embedded a video of the hack in action after the break. If you own a PS4, you may also want to see how to disable the Dualshock LEDs.