The Raspberry Pi Zero is small enough that it could almost be mistaken for a USB gadget, rather than a standalone computer. Maybe that was the inspiration that drove [Novaspirit] to completely “donglify” his Zero.
This is a great convenience hack if you’ve got a Zero just kicking around. With minimal soldering, he converted the Zero’s onboard female USB jacks into a male USB plug. From there on out, it’s all software, and the video (embedded below) takes you through all the steps on Windows.
[Elliot] (no relation, but hey, cool name!) wrote in with his OpenFixture model for OpenSCAD. It’s awesome because it takes a small problem, that nonetheless could consume an entire day, and solves it neatly. And that problem is making jigs to test assembled electrical products: a PCB test fixture.
In the PCB design software, you simply note down the locations of the test points and feed these into the OpenSCAD model. ([Elliot] shows you exactly how to do it using KiCAD.) There are a few more parameters of the model that you can tweak to match your particulars, but you should have a DXF outline for a test jig in short order. Cut that out, assemble, and test.
If you have to make more than a few handfuls of a complicated circuit, it becomes worth it to start thinking about testing them systematically. And with this OpenSCAD model, you can have the test jig up and running before the first prototype boards are back in from the fab. How cool is that?
A lot of people are scared of composting. After all, if the temperatures or humidity go badly wrong, you can end up with dried-out trash or a stinking soup. Getting the balance right is a secret known to the ancients: toss it in a big pile in your backyard. But what if you don’t have a big backyard?
Amalgamate is a composting setup for the urban dweller, or for people who just don’t like bugs. [Jamie] built it as her first Raspberry Pi project, and that makes it a great entrée into the world of things. But it’s no lightweight: the software measures temperature and humidity, and lets you schedule watering and rotating the compost. And of course, if you’re a micromanager, you can get up-to-the-minute vitals on your cellphone and tweak everything to run just perfectly. Continue reading “Amalgamate Is The Internet Of Compost”
Say you have a team of French engineers, a lake in the summer, a wizened old machinist, and some gigantic bungee cords. What would you build? The answer is clear, a human-launching crossbow. (Video, and making-of embedded below.)
You can start out watching the promo video because it looks like a lot of fun, but don’t leave without watching the engineering video. What looks like a redneck contraption turns out to be painstakingly built, and probably not entirely a death trap. The [Rad Cow] team even went so far as to purchase metal cart wheels.
Everyone else on the Intertubes would tell you not to do this at home. We say go for it. That is, draw up reasonable plans, work with an obviously competent machinist, and make something silly. It’s not going to be more dangerous than the stuff that [Furze] pulls off.
Hi all, and welcome to the first installment of Hackenings, our review/preview of the week in global hackerspaces. If you’d like to get the news out about upcoming events at your space, get us an e-mail before Thursday to get it published on Saturday. If you’d just like to brag, any time is fine. Drop us a line at tips@hackaday.com and put [Hackenings] in the subject to make sure that we see it.
This week we’ve got two stories of hackerspaces on the move, but they couldn’t be more different. The Burbank Makerspace has upgraded to fancier new digs, while Cairo Makerspace‘s building collapsed, and now they’re taking their show on the road with a hackerspace-in-a-van.
[ttsiodras] tells an epic tale of getting a custom Debian kernel installed on an Asus MemoPAD (ME103K) tablet. Skipping to the end of the saga, he discovers what looks like serial data coming out on the headphone jack when the system boots, but the signal was so distorted that he couldn’t simply interpret it. The solution turns out to be attaching a level-converter chip.
A level converter is a non-inverting amplifier, usually with a Schmitt trigger for immunity against noise. In this case, it acts like a “binarizer” — outputting a high voltage when the input rises above a threshold, and a low when it drops below. It’s the right part when you need to clean up a messy digital signal, and in this case works just fine because the capacitive distortion effects slow down both the leading and trailing edges of the signal, keeping the serial data’s timing intact.
That was the spoiler. If you want to read up on putting a custom Linux on an Android device, check out [ttsiodras]’s first post where he backs the machine up, and the second where he gets his custom kernel up and running. If you’re ever faced with an Android tablet that hasn’t been owned yet, or if you just have a DIY streak, this should help you get started.
Using the audio jack for serial is actually not uncommon, and discovering a serial terminal that listens at boot time is our favorite way to wedge a Linux OS into odd devices. So when you see a funny, distorted signal coming out at 115,200 baud, take a moment to clean its edges up and see what you’ve got.
One of our favorite hacker-scavengers on YouTube, [The Post-Apocalyptic Inventor], has been connecting his Raspberry Pi up to nearly every display that he’s got in his well-stocked junk pile. (Video embedded below.)
Modern monitors with an HDMI input connect right up to the Pi. Before HDMI came VGA, but the Pi doesn’t do that natively. One solution is to use a composite-to-VGA converter and pull the composite signal out of the audio jack. Lacking the right 4-pole audio cable, [TPAI] soldered some RCA plugs directly onto the Pi, and plugged that into the converter. On a yet-older monitor, he faced a SCART adapter. If you’re European, you’ll know these — it’s just composite video with a different connector. Good thing he had a composite video signal already on hand.
The pièce de resistance, though, was attaching the Pi to his 1980 Vega TV set. It only had an antenna-in connector, so he needed an RF modulator. With a (presumably) infinite supply of junk VCRs on hand, he pulled an upconverter out of the pile, and got the Pi working with the snazzy retro TV.
