Notebook

Build logs and notes from the bench.

The pen plotter draws its first picture
★ FEATURED
Build Log

The pen plotter draws its first picture

The pen plotter is built, wired and drawing. Its first picture is a "hypnotic H" for Hypnochip: the H's outline in five rings 1.3 mm apart, one continuous line, about 100 seconds.

#pen plotter#3d printing#steppers
A tour of Bench, one week in
Bench

A tour of Bench, one week in

In a week, Bench has grown from an Ohm's law calculator into the place where every project lives twice: on a canvas that simulates the circuit, and on the desk where I build it for real.

#bench#simulation#esp32
Electronics

First stepper motor, and why it only hummed

A 28BYJ-48 stepper turns cleanly up to 18 RPM, driven by the ESP32 through the PCA9685 servo driver and a ULN2003 board. This is milestone 1 of the pen plotter.

#stepper#pca9685#esp32
Electronics

First servo on the PCA9685 driver

An SG90 on channel 8 of the PCA9685 servo driver sweeps all the way (600 → 2400 → 1500 µs) when the ESP32 tells it to.

#servo#pca9685#power#esp32
Electronics

Building the SEAF helmet light

The SEAF helmet light works on the real bench. A 9 V battery powers an ESP32 and an RGB LED (all three colours on, so it looks white).

#helldivers#ir#transistor#esp32
Electronics

Wiring the zoom knob, and a long debugging session

The Asteroid Test now has a working zoom knob: a B10K panel pot in the rig that zooms the view 1× / 2× / 4× around the digger.

#potentiometer#debugging#esp32
The studio rig
Build Log

The studio rig

I designed and 3D-printed an electronics studio rig, and both projects now live in it. The base holds the breadboards, the boards and the wiring.

#3d printing#rig#workbench
Electronics

A joystick-steered asteroid digger on the Nextion

A second ESP32, straight out of the package (still running Espressif's 2017 factory firmware), now runs Asteroid Test: a Spacecavator-style asteroid on the Nextion, and a little yellow digger I steer…

#joystick#nextion#game#esp32
Electronics

The Nextion display follows the LEDs, after moving the serial port

My Nextion 2.4" display (NX3224T024_011) is lit and cycling red → green → blue in step with the three LEDs, driven by the ESP32. The Bench canvas mirrors the LEDs and the screen at the same time.

#nextion#display#esp32
Electronics

The ESP32 powers the LEDs itself, and the current has to come home

Three LEDs driven straight from ESP32 pins, and why the current needs a wire back to GND.

#esp32#leds#breadboard#power