In this project, I mount the electronics from my single-key USB keyboard project to the back of an industrial mushroom push button switch. The finished big red button now activates my screensaver with a single overly-large button press. The biggest issues in this project were where to mount the USB electronics and how to connect the USB cable between the button and my computer.
In this video, I build a 3D Printed Desk lamp. The basic design came from Thingiverse, but I repurposed my LM2576 Constant-Current design to serve as a dimmer. It all started when I found an interesting lamp on thingiverse, which used 75mm air hose segments from another model to make a flexible articulating desk lamp. What appealed to me about this project is the size of it, and the use of COB LED panels, which I’ve been wanting to experiment with.
Every few years I revisit the idea of building an ECG machine. This time I was very impressed with how easy it is to achieve using the AD8232, a single-lead ECG front-end on a chip. The AD8232 is small (LFCSP package) but breakout boards are easy to obtain online.
There are times you find yourself looking for a relatively high voltage (100V to 200V often in my case) but low current DC power supply. I have zener diodes that are higher than 30V, which makes the lab supply useless, and filament LEDs with forward voltage over 60V. When I need to test them quickly, I used to hook up a simple rectifier circuit to a variable AC power supply (nothing more than a slidac with isolation transformer). While this gets job done, the setup is capable of supplying much too high current (1A or more), so I was always very nervous and extra careful in handling the circuit. All I need is a little HV generator that gives me around 200V DC and only capable of supplying a milliamp or less. Realizing that I do have such design available – one of the Nixie supply circuit – I just decided to put one together to use.
Sasa Karanovic shared a how-to on making a IoT LED dimmer:
Making a IoT LED dimmer that you can control via your PC, phone, tablet or any other device connected to the network is super simple, and I’m going to show you how.
I’m sharing my three channel LED dimmer that you can use to dim single RGB LED strip or dim three separate LED channels. I want to be able to control lights above my desk and also mix warm white and cool white strip to give me more flexibility over lighting while I’m working, taking pictures or watching movies.
I decided to make my own Atari 5200 analog controller, using a sparkfun thumbstick together with ADC and digital pot to do the potentiometer scaling. The controller is aesthetically a bit rough, consisting of a pcboard mounted to a chunk of hardboard, but it’s fully functional. I also recommend Ben Heck’s “Atari 5200: Making a Better Controller” video.