Day: October 3, 2022

Lithium-Ion Batteries Are Easy To Find

October 3, 2022 by 43 Comments

In the first article, I’ve given you an overview of Lithium-Ion batteries and cells as building blocks for our projects, and described how hackers should treat their Lithium-Ion cells. But what if you don’t have any LiIon cells yet? Where do you get LiIon cells for your project?

Taking laptop batteries apart,  whether the regular 18650 or the modern pouch cell-based ones, remains a good avenue – many hackers take this road and the topic is extensively covered by a number of people. However, a 18650 cell might not fit your project size-wise, and thin batteries haven’t quite flooded the market yet. Let’s see what your options are beyond laptops. Continue reading “Lithium-Ion Batteries Are Easy To Find” →

An Automated Digitizer For 35mm Slides

October 3, 2022 by 12 Comments

Slides make for great old-timey fun, but it’s awesome to have a digital backup of your old photos, too. An automatic digitizer can make quick work of your collection, and this build from [rbwood53] will do just that.

The digitizizer is based on a Kodak carousel slide projector. It’s fitted with LED strips instead of the original light source, which are used to illuminate the slides themselves. An Arduino Nano is used to command a camera to take photos, via a hacked-up shutter release remote. The camera is set up with a zoom lens and relies on auto-focus to get crisp, clear images of the slides. The Arduino is also charged with telling the carousel system to advance to the next slide as required. It keeps count as the slides go by, so it stops when the entire carousel has been imaged.

Overall, it’s a straightforward build that automatically imaged over 40 boxes of slides for [rbwood53] without issue. If you’ve got a smaller collection to digitize, you might find this simple 3D-printed adapter to be useful, too!

Homebrew LED Strips That Are HomeKit-Compatible

October 3, 2022 by 6 Comments

Google, Amazon and Apple are all duking it out for supremacy in the smart home space. As you’ve probably noticed, cheaper smart lights and the like typically don’t offer connectivity with Apple’s HomeKit system. However, if you want some smart lighting that works in that ecosystem without breaking the bank, you can always build your own!

This simple build uses an ESP8266-01S as the brains of the operation. It’s a cut-down board that only has two GPIO pins available, but for this job, that’s enough. It’s paired with a simple relay for switching a single-color LED strip on and off, and an MP2307 buck converter for power. The code loaded onto the ESP8266 is simple, and allows it to connect to Wi-Fi and link up with Apple HomeKit for control.

Let’s say you’re a real fancy-pants, though, and you want RGB-addressable LEDs for your HomeKit setup. No problem, you can do that too! It’s as straightforward as hooking up an ESP8266 to some WS2812B LED strip and flashing the right firmware that emulates an Elgato EVE LED strip. You can even activate special lighting effects on the via the EVE app if you so desire, to take advantage of the fully-addressable nature of the strip.

There are plenty of off-the-shelf solutions in this space, but many of them are quite expensive for what you actually get in the box. Sometimes building your own is more fun, too. Alternatively, if you don’t like Apple’s smart home solutions, you can always try a more open alternative. Video after the break.

Continue reading “Homebrew LED Strips That Are HomeKit-Compatible” →