Stenokeyboard

Oct 2025 - Dec 2025

Figure 1: Assembled PCB

A stenokeyboard is a keyboard that forms words based on key combinations that mimic pronunciation which enables faster typing. It has been popular for decades among court reporters.

Figure 2: Working demo

I designed the PCB, soldered the 0402 components, coded the firmware in C, and tested the system myself.

There were some mistakes and interesting considerations that came up during the process:

• For PCB layout, since each GPIO is mapped to a key switch, I cross referenced pin locations to keep routing short and clean.
• During assembly, incorrect load capacitance values for the external crystal driving the USB peripheral caused communication issues with the host computer. Debugging involved using an oscilloscope and running toggling functions to rule out a chip failure.

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