Crystal Hammer

⏱️Overview

This is a tiny project, that took about 2 days. It uses the “Bluepill” MCU board with small OLED display for info texts and has few buttons to toggle LED lights and relays for audio outputs.

✍️Motivation

For many years (seems about 20) I was using just old logic chips. And it felt ancient, so I finally decided to do it with bluepill.
Having a small display is nice and informative. With many inputs and outputs left, there is still room for later changes.
This “console” is very useful and has a place just left of my keyboard.
Has no case yet, and I’m not sure if it will, I’m just covering it with a black cloth.

📂Sources

Sources are here.
Actually just using that Arduino .ino since it’s a small project.
I was editing code in VSCodium, then building and uploading using the worst Arduino IDE 1.8.19.

📊Features

• STM32F103C8T6 “Bluepill” MCU – cheap, but decent
• Small OLED display – for OSD info texts, saying what pressing button did
• Few (8) buttons, for toggling:
  • 3 LED lights – and adjust their brightness with PWM
  • Audio DAC output to: speakers / headphones / bathroom (12V relays)
  • USB switch (5V relays) – directs keyboard (KC4) and mouse to PC or laptop
• Just as a place to mount my 2 other important buttons:
  • LCD monitor input switch
  • PC power on/off