An ESP32 ESPHome device in the furnace room reads a differential-pressure sensor across the filter and watches the furnace control board’s status LED. Home Assistant turns the raw pressure into blower speed, filter loading, and a replace-filter alert. The threshold comes from a real clean-filter-vs-old-filter experiment, not a guessed limit.

A stock Zigbee door/window sensor, with its Hall-effect chip desoldered and two wires brought out in its place, becomes a cheap, battery-powered interface for any simple contact: reed, pressure pad, or float switch. Built to stop Home Assistant from switching off the office lights while sitting still at the desk; the same trick already covers a toilet tank float and a Christmas tree water level.

A 3D-printed clip mounts a submersible float switch on a toilet tank’s overflow tube and wires it into the same desoldered-Hall-effect Zigbee mod used for the office chair sensor. The result: Home Assistant catches a stuck fill valve before it turns into a running toilet, and gets a flush count for free.

A basement dehumidifier whose built-in control restarts the compressor within 30 seconds of finishing a cycle. Two ESPHome boxes replace that with a wide, adjustable deadband and an anti-short-cycle timer, no Home Assistant, no cloud. Ships as three config pairs: a learning-only simple pair, a full pair for a home Wi-Fi network, and a full pair for buildings with no Wi-Fi at all.

Wiegand data lines idle at 5V, and the ESP32 is not 5V-tolerant. You don’t need a level-shifter IC or a resistor divider. A single signal diode does the job, and it does it better.

MicroPython rewrite of the Impression 5 giant calculator. 9-digit NeoPixel 7-segment display with 20 physical buttons, running on ESP32 or Raspberry Pi Pico.

ESPHome config for a Wiegand keypad reader built on a thin-edge philosophy: the device only captures input and relays it to Home Assistant. Now folded directly into the garage’s RATGDO board instead of running on its own standalone ESP32.

Cable/PCB adapter that converts any VirtualAccess/GW power supply connector to a standard USB-to-TTL/3.3V serial adapter for quick debug access on Westermo GW-series devices.

Daughter PCB that exposes the internal USB port externally on the VirtualAccess GW1152 router from Westermo.

Two ESPHome configs for a SONOFF S31 smart plug that auto power-cycles a device when it stops responding. One using ICMP ping loss detection, one using Home Assistant API connection loss.

Python tool for validating cellular SIM activation on a Digi WR21 router. Auto-detects carrier, cycles through known APNs, and reports results via a 2-line I²C LCD with RGB rotary encoder interface.

Arduino library for reading an array of photocell (LDR) sensors with a sliding-window moving average and configurable threshold detection. Supports multiple sensors with individual sample rates.

Arduino Micro Pro HID device that prevents screensavers when room lights are on. Uses a dual-criteria light-change algorithm to distinguish light switches from gradual daylight changes.

Interactive museum exhibit at Impression 5 Science Center. Visitors use RFID tablets to explore botanical migration routes on a lit map, with green/red LED feedback guiding correct selections.

Arduino Mega replacement for Impression 5 Science Center’s giant calculator exhibit. Custom LED display and keypad controller using big-number arithmetic.

Eagle CAD Arduino Mega shield PCB designed for Impression 5 Science Center exhibits. Standardizes wiring, connectors, and power for the Giant Calculator and Genome Map projects.

Raspberry Pi Zero W chore tracker. Physical buttons and NeoPixel LEDs show daily task progress in a tactile, screen-free display for kids.

Custom Arduino shield redesigned for an intro Arduino class after SparkFun discontinued the original Danger Shield. Adds improved components and layout while keeping the same hands-on exercise set.

A quick hands-on demonstration giving novice users a concrete feel for what an Arduino is, what it can do, and how easy it is to get started. Progressing from blinking an LED through buttons, analog I/O, servo control, and sound.

Detroit Maker Faire demonstration reproducing Edison’s original incandescent light bulb. Pencil lead as the filament, D-cell batteries in a PVC pipe as the power source, and a glass bottle as the envelope.

Non-blocking, interrupt-driven Arduino library for the VLSI VS1053 audio decoder chip. Streams MP3, AAC, Ogg Vorbis, FLAC, WMA, and WAV from SD card over SPI.

The electronics half of the HarpsiGourd. 15 pumpkins wired as capacitive touch keys driving a Music Maker MP3 shield. Pairs with the CNC Faux Piano shell for exhibition use.

Oversized playable Tetris built from 200 addressable RGB LEDs across a 10×20 grid, controlled by an Arduino with a Wii Nunchuk. Presented at Detroit Maker Faire and used in the Lansing Silver Bells parade float.

Exercise bicycle with an automotive alternator powering a Jacob’s Ladder spark display. The spark activates when the rider hits 88 MPH on the speedometer. Shown at an early Detroit Maker Faire.

Full LCARS-style bridge simulator: hand-built capacitive touch consoles at every station, BSG 2003 aesthetic, support craft, narrated training, and spectator viewer portals.

A fully open source, 38-foot, 4-lane pinewood derby timing system built for Cub Scout Pack 2222. Arduino Mega, custom PCB, IR sensors, solenoid starting gate, and 7-segment displays.

Arduino Mega sketch for sequenced Christmas lights using Vixen lighting software. Supports daisy-chaining multiple Arduinos for up to 51 channels per board via serial passthrough.

Reverse-engineered the IR protocol between Syma toy helicopters and their controllers using Arduino, enabling cross-control of multiple choppers or repurposing the controller for other devices.

Arduino library for measuring free RAM at runtime. Critical for debugging out-of-memory crashes on AVR boards with as little as 2 KB of RAM.

The original non-blocking, interrupt-driven Arduino library for the SparkFun MP3 Player Shield (VS1053). Superseded by the generalized vs1053_for_SdFat library.