LEAP#446 RGB Joule Thief Night Light
I recently got hold of some 5mm RGB Flashing LEDs from a seller on aliexpress - some slow and fast flashing varieties just out of curiosity. Here I’ve put one the slow-flash kind in a “night light” circuit.
I decided to power from a little 1.5V CR1216 coin cell. To boost the voltage sufficient to power the LED, I’ve attached a toroidal joule thief circuit. The oscillating voltage produced by the joule thief is not suitable for the flashing LED as it is liable to get stuck on a single colour, so I’ve added a diode/capacitor charge pump to provide a more stable power source for the LED.
As always, all notes, schematics and code are in the Little Electronics & Arduino Projects repo on GitHub
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LEAP#442 Boldport ResPot
As any good electronics hobbyist must have done, I’ve already built a decade programmable resistor box - see LEAP#414 - but this is one with the Boldport twist. Yes, real pots.
A decade box is an old-fashioned bit of test equipment, allowing an arbitrary resistance to be dialed up to order.
As always, all notes, schematics and code are in the Little Electronics & Arduino Projects repo on GitHub
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LEAP#441 Pollen8
“Pollen8” is an exploration of contrasts and patterns in a freeform wire circuit.
I was interest in playing with a design that avoided the harsh angularity of most electronic circuits, instead using graceful lines that attempt to mimic a more organic structure.
The second goal was to achieve a chameleon-like LED display, where the visual effect depends on the perspective of the viewer: random from some angles, but clearly sequenced from others.
I created this for the Hackaday Circuit Sculpture Contest.
As always, all notes, pictures and schematics are in the Little Electronics & Arduino Projects repo on GitHub
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LEAP#440 Logging Data with Adafruit IO
I wanted a simple way to log the voltage of the LEAP#439 QX5252 Solar Night Light, rechargeable battery to get a sense of the overnight discharge and daily recharge pattern.
It didn’t need to be particularly accurate, but I did want to get a fairly continuous log at least every 5 minutes or so. Sounds like a perfect case for some Arduino-powered data logging!
I could just capture some data locally to an SD card, but sending the data to the cloud is much more appealing, as it means I can access and do some analysis at any time without needing to be local to the device.
There are many established and roll-your-own solutions for this problem, but I’ve taken this as an opportunity to experiment in particular with Adafruit IO:
- collect measurements to a feed
- create a simple dashboard
- setup triggers to notify on low/high voltage
I was quickly impressed by Adafruit IO! It is extremely easy to get something simple up and running. It doesn’t over-reach in terms of features (or price), so I can see this being a great prototyping platform for relatively straight-forward control and data collection. But this also means you can probably imagine much more ambitious projects that require more than Adafruit IO has to offer.
For my initial problem - log some data about the state of a rechargeable battery over a couple of days - it was perfect. Literally took me 10 minutes from signing up at Adafruit to when I had data streaming into a feed. Doing more research on how it worked and writing my notes took far longer;-)
As always, all notes, schematics and code are in the Little Electronics & Arduino Projects repo on GitHub
Here’s a sample of the voltage measurements I’m seeing on the dashboard:
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