A single-button MIDI controller that uses the V-USB library to emulate a class-compliant MIDI device on an ATTiny85.

Documentation: Geek Funk Labs

Code: GitHub

Store Link: Tindie

Mini USB Keyboard https://github.com/andyclymer/minikbd

Front panel for AC Shunt Box

Production version.

Two sets of 3 boards are needed. One set of 3 boards costs 32.6$.

Adapter for Arduino for SBB Split Flaps

GPS lid for kimchi board

One-Shot stimulator based on 555.

A simple One-Shot featuring: Optional voltage regulator, adjustable output, buffer on output.

More details here at Hackaday,io.

Stanley A Meyer Steam board

HiFi Lid for the Kimchi Linux SBC from GroupGets

Uses SMA size surface mount diodes (ie. S1B-13-F). Used to power GPS on a drone with a 1S battery before powering up the flight controller

PCB for the SquishBox, a Raspberry Pi-powered FluidSynth MIDI sound module. Plugs onto the Raspberry Pi GPIO header and provides a 16x2 character LCD, PCM5102 audio outputs, and two buttons. Can be 5V or 9V-powered.

Documentation: Geek Funk Labs

Code: GitHub

Store Link: Tindie

Vintage LED sign, modern controller.

Z80-512K is an RC2014-compatible CPU and memory module, designed to run RomWBW firmware

Project’s GitHub repository: github.com/skiselev/Z80-512K

You can use this little board to adapt a Bourns 3296W (or Vishay T93YA) trimpot as a bias adjustment control in a tube amplifier. The bias supply from the amp goes to “B.IN” pad, bias supply out comes from the “B.OUT” pad, and the “G” pad goes to the main bias resistor to ground depending on the circuit. The resistor in parallel is an emergency pull-down resistor. I took this idea from the Valve Wizard. They write: “This ensures that if the pot wiper fails to make good contact with the rack (because it is dirty or worn out, say) the grid leaks will effectively be connected directly to the raw bias supply through R1 instead, biasing the valves safely cold. R1 should have a value of about ten times [the trim pot] so it has negligible effect on the rest of the design.”

Schematics, EAGLE and Gerber files, and other references here: https://drive.google.com/drive/folders/1CyXvsXiN4TgLzc1Nf8XQB_ZOHwcMmx7g?usp=sharing

Pretty much pulled from the datasheet and inspired by the circuitbenders.co.uk board.

BILL OF MATERIALS: - R1: 3 kOhm 1% Metal Film - C1: 0.1 uF 50v MLCC (C0G/NP0 or X7R) - I/O pads: either just wire or Phoenix 1729131 for terminals - Trim pot: Bourns 3296W-1-223LF (22 kOhm, 25k will work) - LTC1799 module - pads “2” and “3” go to a panel mount pot. You can use C100K or C500K for wider range of adjustment. I used this in an ART Multiverb and actually preferred the taper of audio/logarithmic pots over the reverse-log. If using the audio/log pot, run the wire from the pin 3 pad to pin 1 of the pot.

Here is a Mouser cart with all of the parts: https://www.mouser.com/ProjectManager/ProjectDetail.aspx?AccessID=683c34a120

Datasheet: https://www.analog.com/media/en/technical-documentation/data-sheets/LTC1799.pdf Circuitbenders version: https://www.circuitbenders.co.uk/forsale/LTC/LTCPCB.html

MK1 Autopilot for a manned aircraft