Shared Projects

Teleinfo board for raspberry

Buck-Boost Converter with TPS63061 from Texas Instruments. BOM coming soon.

Wemos D1 mini -ILI9341 adapter board with backlight dimming. Designed to work with Squix ESP color weather station project. Please forgive me. Please!?!

This is the board for the QuadBot quadruped robot that recently failed on kickstarter

Two-layer board for the L-Cheapo V1.2 laser cutter

Capacitive touch pad

Version 2 of AN3813K Brushless DC Motor Driver Arduino Shield (PLL Version) for use with VCR Cylinder Motors with precision speed control with feedback.

Specifically designed to be used with the Arduino ProMini PiDuino HAT and the STM32F746G Discovery Board, but can also be used on any Arduino Uno R3 compatible target. Supports both 5V and 3.3V logic with on-board level-shifters.

This version replaces the old Version 1 board. This version has improved voltage ranges and trim control for the V-to-F and F-to-V circuits, adds a flip-flop to make the V-to-F output 50% duty cycle, and fixes the AN3813K chip footprint without the need for an adapter board, as it’s a Shrunk DIP-18 not a Wide DIP-18.

Note: Populate either C1-C3 with R1-R3 or populate C12-C14 without R1-R3. C1-C3 is a low-side filter and C12-C14 is a high-side filter. Only one set is needed. Preference is generally for C12-C14. In either case, those capacitors should be bipolar.

All smaller surface mount discrete parts are 1206 footprint.

ERRATA: This version is missing a very important 10K pull-up resistor from LM331 V-to-F (U301) pin 3 (output) to pin 8 (+5VA). Without the pull-up resistor, the U305 flip-flop will not see the frequency output from the V-to-F and the U304 PLL will not have a frequency reference to lock to, keeping the Torque Error (ET) signal to the AN3813K in the off-condition, and the motor will not run.

Note: The 4046 PLL circuit often doesn’t drive the ET (Torque Error) signal low enough during initial startup to provide enough torque to get the motor spinning. Some clever programmatic manipulation of the Speed and ETR (ET Reference) DAC values after applying the motor enable signal can be made to work as an automatic startup solution.

However, the simplest solution, if manual start is acceptable, is to add a manual push-button between ET and GND to serve as a “start button” for the motor.

Another automatic solution would be to replace the push-button with a MOSFET transistor connected to an unused processor output pin, but that burns another processor pin.

See the AN3813K BLDC VCR Cylinder Motor Driver Arduino Shield PID Version V1 for the PID Version of this board. Both versions are viable solutions depending on preference of Analog PLL circuit or Digital PID via a microcontroller.

Prototyping and Temp/Humid boards for VAYU-NTX Payload board.

Originally constructed at KHM Köln: https://web.archive.org/web/20190221041813/http://interface.khm.de/index.php/lab/interfaces-advanced/radio-signal-strength-sensor/.

Breakout board with molex connectors for the Adafruit 16 channel PCA9685 PWM chip/breakout board.

Mod board for the Jasper synth adding two different XOR waveforms that sound like ring modulation.

XOR1 is Osc2 x LFO (most flexible with an LFO modded for higher rates)

XOR2 is Osc1 x Osc2

The outputs are placed on Osc2’s rotary switch (you’ll have to adjust the lock to allow two extra rotation positions)

(Following images are for a v1 Jasper. Pins may differ slightly in later revisions.)

XOR pin refs

(wire colours below don’t match the above diagram) Jasper XOR wired

Crystal oscillator based clock for the RC2014

RS232 extension board for FT2232 module

A Graphics Shield for arduino using the parallax propeller

Cash Register Calculator

74HC165 chainable button board with pullups