A little over a year ago on YouTube I posted a video on how to make a DIY game controller from scratch with arduino. The video has done very well and opened up some unique opportunities for me including working with my local library to build controllers with kids to teach about electronics and coding. Recently I was emailed by a viewer who explained that he is unable to use his right hand due to a stroke. He expressed interest in developing a one-handed mouse system such that one could control WASD and other buttons in addition to normal mouse actions. I quickly began working during quarantine to develop this controller. Very simply it uses an arduino pro micro board, a joystick, and a few buttons to act as a usb game controller. With https://joytokey.net/en/ software the control inputs are mapped to specific keys. To create the code for this project one must download the arduino joystick library by Matthew Heironimus at https://github.com/MHeironimus/ArduinoJoystickLibrary. Originally the base of the controller had a thin platform on which the mouse rested. However, I found that some mice needed to make full contact with the table surface to function properly. As a result, I created a base version without this thin raised platform. If your mouse only works when making full contact with your mouse pad or desk, use this bottomless version. If you are interested in this project please watch my tutorial video on YouTube: https://www.youtube.com/watch?v=gHSD-KqGbn0&t=10s&ab_channel=Benjijart