Ask HN: What is your hardware/garage side-project?

I've put together illustrations for each habit I'd like to keep, and then printed them on archival paper. I also built a LED calendar to keep track of things and combined it all into a wall frame. I occasionally write project logs on Hackaday[1].

It's fun to work on and I've noticed I'm already keeping up on these habits since they are always on my mind when building. Also the sunk cost has an effect on me to want to get as much out of this project as I can.. even more incentive!

[1] - https://hackaday.io/project/18304-21days-habit-tracker

A very trivial implementation of TCP running atop RS232USB converters connected back-to-back so you can run SSH over USB (or RS232) at around 3Mbps. For tunnels and stuff.

5000 LEDs drilled into 30m^2 worth of plywood, wrote a kernel driver to present the LEDs as a frame buffer on an RPi with Chromium, we (small team) mounted whole thing onto concrete slabs standing in a lake. Another RPi receives SMS text messages using a JS script to decode GSM PDUs with Unicode that are ultimately rendered on the LEDs. Nice graphics are added on top if you write something sweet for example.

A device to virtually switch an SD card out of an RPi and onto a host computer so you can remotely format the SD card and reboot the RPi.

A crawler versus human detector that is a bit simpler than those normally are.

Lots of projects that get tossed because they require expertise outside of my own area. I'm quite bad at finding other tinkerers to cooperate with, unfortunately.

CNC machine shop. I rigged a Sherline mill and lathe with stepper motors, limit switches, electronic touch-off and emergency stop button. I multiplexed the limit switches with a custom designed PCB with Schmitt triggers and an Arduino. I hooked this all up to a stepper motor controller board and power supply, and I placed all that into a custom built enclosure. I connected the controller board to a PC using PCIe parallel port cards. The PC runs LinuxCNC. This lets me machine alumninum into parts modelled in 3D CAD. Then I've machines various tools needed around the shop. I've also made a Turner's cube using the lathe, and again using the mill.

I've also built a custom PS3 style controllers for manhually controlling the CNC machines. This was again done with custom PCBs, joystick and encoder parts, and Arduino.

I'm working towards machining a Stirling engine with my CNC machines. I've also been working on and off on a robotic arm (which is what got me into machining metal parts in the first place).

Unrelated to CNC machining, I've done a small, beginner SDR project: ADS-B receiver built with R820T2 USB SDR and custom built antenna from coax cable and PVC pipes, lets me to track commercial aircraft that frequently fly over my house.

Tickerstorm.io - An algo trading platform in Java (pretty early still).

Difference from other platforms I've found: integrated machine learning phase which reuses the same data pipelines used by the algo when backtesting or trading live. Trying to reuse as many open source frameworks as possible to reduce the amount of new things a user has to learn. Based on Apache Storm, H2O machine learning, guava, Spring Framework etc. Not HF focused.

Most other platforms start off with you coding up your rules and allow you to back test those assumptions. However, this platform also incorporates the discovery phase of these rules rather than just assume you already have a set of rules.

I built a 5-octave, 31-note-per-octave just intonation keyboard with pressure sensitive keys.

I've been working on putting together a thorough writeup, but for now there's just this video which I uploaded today:

https://www.youtube.com/watch?v=Ep52Vh6oAOE