4xMacropad

An ultra low cost, 4 keys mechanical macropad using CH552G.

Build Instruction

Send the PCB to print (See ./pcb)
Purchase all the required materials (See BOM list below)
3D print the base plate (See ./models)
Install the required Arduino library for CH552G and drivers
Visit 4-key Macropad | imuslab or modify the sketch in macrokey_distribute
Flash the CH552G with the sketch

Program Flashing Instructions

Hold and press the PROG button on the PCB
While the button has been held, insert the USB cable into the mini USB port
Release the button when the Arduino code has finished compiling and ready to upload (Timing is important)
Wait for the upload to complete

Bill of materials

0805 LED x 3 (3 different color of your choice)
0805 0.1uF x 2
0805 10kΩ x 7
3 x 3 x 1.5mm micro switch x 1
5PF mini USB port x 1
SOP-16 CH552G x 1
SK12F14 switch x 1

Optional RGB signal lights on the back of the PCB, if you are going with transparent 3D printed case like mine

0805 LED x 3
0805 10kΩ x 3

Photos

See USBHIDMediaKeyboard.h for more details.