$3 Multimeter Teardown

[Diode Gone Wild] and his cat decided to see how a $3 meter worked inside. The meter was marked as a DT-830B and he already had an older one of the same model, and he wondered how they could afford to sell it — including shipping — for $3. You can see a video of his testing, teardown, and reverse engineering below.

What was odd is that despite having the same model number, the size of the meter was a bit different. When he opened the case to install a battery, he noticed the board didn’t look like it had fuses or components appropriate for the rated voltages. He decided the missing parts might be under the board and tested the meter.

In all fairness, for $3, the meter agreed pretty well with his other meters. The AC scale appeared to be little more than a diode feeding the DC meter with some slightly different engineering unit conversion coefficients. Not the most accurate way, but certainly in line with what you’d expect from a $3 meter. Afterward, though, the case and PCB came out and there were no additional components on the other side of the board.

The original DT-830B had beefy resistors where it needed them and — most importantly — a fuse for the current measuring function. The new one had a marking on the case about the type of fuse it uses, but inside there was no fuse, even though there were PCB pads that could have been for a fuse.

Maybe those parts weren’t necessary? After sketching out the schematic, the video shows that in fact, the voltage and power dissipation really did require bigger components. In addition, a connection error could easily put very high voltages right to the IC.

This looked a lot like the DT-832 we saw a while back. That one had a fuse, though, and we aren’t sure if it had better-rated resistors or not. We’ve also seen cheap meters with fuses that weren’t actually used.

Posted in china, multimeter, teardown | Leave a comment

Real Time Satellite Tracker Shows You What’s Going Over Your Head

Whilst modern technology relies heavily on satellites, it’s easy to forget they’re there; after all, it’s hard to comprehend mostly-invisible lumps of high-density tech whizzing around above you at ludicrous speeds. Of course, it’s not hard to comprehend if you’ve built a real-time satellite tracker which displays exactly what’s in orbit above your head at any given time. [Paul Klinger]’s creation shows the position of satellites passing through a cylinder of 200 km radius above the tracker.

Each layer of LEDs represents a specific band of altitude, whilst the colour of the LEDs and text on the screen represent the type of object. The LEDs themselves are good old WS2812b modules, soldered to a custom PCB and mounted in a 3D-printed stand. The whole thing is a really clean build and looks great – you can see it in action in the video after the break

On the software side, a Raspberry Pi is in charge, running Python which makes use of pyorbital for some of the heavy lifting. The data is taken from space-track.org, who provide a handy API. All the code is on the project GitHub, which also includes the 3D print and PCB files.

[Paul] answers questions in the reddit thread, and gives more detail in this reddit comment. The project was inspired by one of our favorite sites: stuffin.space.

Some of the satellites the device displays are de-commisioned and inactive. Space junk is a significant problem, one which can only be tackled by a space garbage truck.

Posted in Raspberry Pi, satellite, space, tracker | Leave a comment

Jump into AI with a Neural Network of your Own

One of the difficulties in learning about neural networks is finding a problem that is complex enough to be instructive but not so complex as to impede learning. [ThomasNield] had an idea: Create a neural network to learn if you should put a light or dark font on a particular colored background. He has a great video explaining it all (see below) and code in Kotlin.

[Thomas] is very interested in optimization, so his approach is very much based on mathematics and algorithms of optimization. One thing that’s handy is that there is already an algorithm for making this determination. He found it on Stack Exchange, but we’re sure it’s in a textbook or paper somewhere. The existing algorithm makes the neural network really impractical, but it makes training easy since you can algorithmically develop a training set of data.

Once trained, the neural network works well. He wrote a small GUI and you can even select among various models.

Don’t let the Kotlin put you off. It is a derivative of Java and uses the same JVM. The code is very similar, other than it infers types and also adds functional program tools. However, the libraries and the principles employed will work with Java and, in many cases, the concepts will apply no matter what you are doing.

If you want to hardware accelerate your neural networks, there’s a stick for that. If you prefer C and you want something lean and mean, try TINN.

Posted in ai, artificial intellegence, kotlin, neural network, Software Development, software hacks | Leave a comment

Wave-Powered Glider Delivers Your Message In A Bottle

Setting a bottle adrift with a message in it is, by most measures, an act of desperation. The sea regularly swats mighty ships to their doom, so what chance would a tiny glass bottle have bobbing along the surface, subject as it is to wind, waves, and current? Little to none, it would seem, unless you skew the odds a bit with a wave-powered undersea glider to the help the bottle along.

Before anyone gets too worked up about this, [Rulof Maker]’s “Sea Glider” is about a low-tech as a device with moving parts can be. This craft, built from a scrap of teak and a busted wooden ruler, is something that could be assembled in a few hours from whatever you have on hand, even if you’re marooned on an uncharted desert isle. The body of the craft sprouts a set of horizontal planes that can swivel up and down independently. The key to providing a modicum of thrust is that each plane is limited to a 90° swing by stop blocks above and below the pivot. The weighted glider, tethered to the bottle, bobs up and down below the waves, flapping the planes and providing a tiny bit of thrust.

Was it enough to propel the bottle any great distance? We won’t ruin the surprise, but we will say that [Rulof]’s essentially zero-cost build appears to have improved the message in a bottle bandwidth at least somewhat. It’s not a Hackaday Prize-winning robotic sea glider, but it’s a neat hack nonetheless.

Once again, thanks to [Baldpower] for the tip.

Posted in message in a bottle, misc hacks, sea glider, submarine | Leave a comment

Robot + Trumpet = Sad Trombone.mp3

[Uri Shaked] is really into Latin music. When his interest crescendoed, he bought a trumpet in order to make some energetic tunes of his own. His enthusiasm flagged a bit when he realized just how hard it is to get reliably trumpet-like sounds out of the thing, but he wasn’t about to give up altogether. Geekcon 2018 was approaching, so he thought, why not make a robot that can play the trumpet for me?

He scoured the internet and found that someone else had taken pains 20 years ago to imitate embouchure with a pair of latex lips (think rubber glove fingers filled with water). Another soul had written about measuring air flow with regard to brass instruments. Armed with this info, [Uri] and partners [Ariella] and [Avi] spent a few hours messing around with air pumps, latex, and water and came up with a proof of concept that sounds like—and [Uri]’s description is spot-on—a broken robotic didgeridoo. It worked, but the sound was choppy.

Fast forward to Geekcon. In a flash of brilliance, [Avi] thought to add capacitance to the equation. He suggested that they use a plastic box as a buffer for air, and it worked. [Ariella] 3D printed some fingers to actuate the valves, but the team ultimately ended up with wooden fingers driven by servos. The robo-trumpet setup lasted just long enough to get a video, and then a servo promptly burned out. Wah wahhhh. Purse your lips and check it out after the break.

If [Uri] ever gets fed up with the thing, he could always turn it into a game controller a la Trumpet Hero.

Posted in air pressure, latex lips, musical hacks, robots hacks, servo, trumpet | Leave a comment

Teardown: Sony’s New Aibo goes Under the Knife

In a complete surprise, Sony has moved to release the latest version of their robotic dog series, Aibo, in North America. The device is already out in Japan, where there are a number of owner’s clubs that would rival any dedicated kennel club. Thanks to the [Robot Start] team, we now have a glimpse of what goes into making the robotic equivalent of man’s best friend in their teardown of an Aibo ERS-1000.

Sony Aibo Battery Removal

According to Yoshihiro of Robot Start, Aibo looks to be using a proprietary battery reminiscent of the Handycam camcorders. Those three gold contacts are used for charging on the rug shaped power base that Aibo will periodically return to in order to take a”nap”. There are a couple of square OLED screens behind those puppy dog eyes. They are full-color OLEDs somewhere in the one-inch ballpark. Between the screens is a capacitive touch sensor that wraps around to the top of the head that are also pressure sensitive. Sony Aibo Teardown OLED Eyes 2018

According to Sony’s press release, the fish-eye camera housed in Aibo’s snout is used to identify faces as well as navigating spaces.

Laying out all the major parts out together certainly drives home the complexity of the latest Aibo. It’ll be interesting to see the progression of this device as all of them come equipped with 4G LTE and 802.11 b/g/n WiFi that connect to Sony’s servers for deep learning.

Sony Aibo Teardown Complete 2018

New behaviors are supposed to download automatically as long as the device is under the subscription plan. While Sony has no current plans to integrate with any voice-activated virtual assistant, we can still look forward to the possibility of some expanded functionality from the Hackaday community.

For the rest of the teardown photos make sure to head over to [Yoshihiro]’s write up on Robot Start. Also just in case anybody cared to see what happens when the first generation Aibo ERS-111 from 1999 meets the 2018 Aibo ERS-1000, you’ll find the answer in the video below:

Posted in Aibo, electomechanical, robots, robots hacks, sony, teardown | Leave a comment

Blazing Fast Raspberry Pi Display Driver Will Melt Your Face then Teach You How

Reader [poipoi] recently wrote into our tip line to tell us about an “amazingly fast” Raspberry Pi display driver with a README file that “is an actual joy to read”. Of course, we had to see for ourselves. The fbcp-ili9341 repo, by [juj], seems to live up to the hype! The software itself appears impressive, and the README is detailed, well-structured, educational, and dare we say entertaining?

The driver’s main goal is to produce high frame rates — up to around 60 frames per second — over an SPI bus, and it runs on various Raspberry Pi devices including the 2, 3 and Zero W. Any video output that goes to the Pi’s HDMI port will be mirrored to a TFT display over the SPI bus. It works with many of the popular displays currently out there, including those that use the ILI9341, ILI9340, and HX8357D chipsets.

The techniques that let [juj] coax such frame rates out of a not-terribly-fast serial bus are explained in detail in the README’s How it Works section, but much of it boils down to the fact that it’s only sending changed pixels for each frame, instead of the full screen. This cuts out the transmission of about 50% of the pixels in each update when you’re playing a game like Quake, claims the author. There are other interesting performance tweaks as well, so be sure to check out the repo for all the details.

There’s a video comparing the performance of fbcp-ili9341 to mainline SPI drivers after the break.

We’ve covered similarly performance-focused SPI display drivers for the esp8266, esp32, and teensy, if you’re looking to use a more lightweight computing platform.

[Thanks again for the tip poipoi]

Posted in display driver, graphics, ILI9341, Raspberry Pi, spi | Leave a comment

Stock Looking PSP Hides a Raspberry Pi Zero

We don’t see that many PSP hacks around these parts, perhaps because the system never attained the same sort of generational following that Nintendo’s Game Boy line obtained during its heyday. Which is a shame, as it’s really a rather nice system with plenty of hacking potential. Its big size makes it a bit easier to graft new hardware into, the controls are great, and there’s no shortage of them on the second-hand market.

Hopefully, projects like this incredible “PiSP” from [Drygol] will inspire more hackers to take a second look at Sony’s valiant attempt at dethroning Nintendo as the portable king. With his usual attention to detail, he managed to replace the PSP’s original internals with a Pi Zero running RetroPie, while keeping the outside of the system looking almost perfectly stock. It wasn’t exactly a walk in the park, but we’d say the end definitely justifies the means.

The first half of the project was relatively painless. [Drygol] stripped out all the original internals and installed a new LCD which fit so well it looks like the thing was made for the PSP. He then added a USB Li-ion charger board (complete with “light pipe” made out of 3D printer filament), and an audio board to get sound out of the usually mute Pi Zero. He had some problems getting everything to fit inside of the case. The solution was using flat lithium batteries from an old Nokia cell phone to slim things down just enough to close up the PSP’s case with some magnets.

What ended up being the hardest part of the build was getting the original controls working. [Dyrgol] wanted to use the original ZIF connector on the PSP’s motherboard so he wouldn’t have to modify the stock ribbon cable. But it was one of those things that was easier said than done. Cutting out the section of PCB with the connector on it was no problem, but it took a steady hand and a USB microscope to solder all the wires to its traces. But the end result is definitely a nice touch and makes for a cleaner installation.

We’ve covered the exciting world of PSP homebrew, and even DIY batteries built to address the lack of original hardware, but it’s been fairly quiet for the last few years. Here’s hoping this isn’t the last we’ve seen of Sony’s slick handheld on these pages.

Posted in Games, handheld, pi zero, psp, PSP Hacks, Raspberry Pi, retropie, zif | Leave a comment

Hackaday Links: October 21, 2018

A few weeks ago, we got word [Fran] was being kicked out of her workshop. You might remember [Fran] from her exploits in reverse engineering the launch computer for the Saturn V, her work on replicating the DSKY from an AGC, her visit to the Air & Space Museum annex (so jealous), and her other musical adventures. Why is she getting kicked out? Philly’s getting gentrified, ya jabroinis. Now, there’s a GoFundMe for a new Fran Lab. Go on and ring that bell.

Everyone needs a Sharpie sitting around, so how about one that weighs a pound or so? [MakingStuff] created a new body for a big ‘ol Sharpie marker, complete with knurling. Oh, man, the knurling.

A Powerball ticket costs $2. Last Friday, the expected return on a single Powerball ticket was more than $2. This doesn’t happen often, but last Friday the most logical course of action for everyone was to buy all the Powerball tickets they could.

Boston Dynamics built another dog robot and made it dance to Uptown Funk because we haven’t heard that song enough. No one has listened to Uptown Funk enough times in their life. It’s a great song that never gets old or overplayed.

[Wintergatan] is building a drum machine. You might remember this artisan of plywood from various marble machine builds that also play music. This build goes deep into the techniques of building gigantic mechanical contraptions out of plywood and steel.

Speaking of plywood, Rockler had a contest a while back to build something out of a single sheet of plywood. [OSO DIY] came up with the most interesting table I’ve ever seen. A lot of the entries into this plywood contest turned the plywood on its end, resulting in something that looks like it’s made out of skateboard decks. [OSO DIY]’s coffee table is no exception; it’s basically just a panel of edge-grain plywood made into a table. Where this gets really good is the actual design of the table. It’s clearly a mid-century modern piece, with threaded inserts holding the legs on. However, instead of something that was pressed out of a factory, this table just exudes an immense amount of manual labor. It’s a counterpoint between craftsmanship and minimalist design rendered in plywood and by far one of the most interesting pieces of furniture made in the last few years. Here are some more entries that also capitalize on edge-grain plywood

Posted in boston dynamics, fran, fran lab, gofundme, Hackaday Columns, Hackaday links, plywood, powerball, wintergatan | Leave a comment

The Polyphonic Analog/Digital Synth Project

[Matt Bradshaw]’s entry in the Hackaday Prize is Polymod, a modular digital synthesizer which combines the modularity of an analog synth with the power of a digital synth. Each module (LFO, Envelope Generator, Amplifier, etc.) are connected with audio cables to others and the result is processed digitally to create music.

The synth is built with a toy keyboard with each key having a tactile switch underneath it, contained inside a wooden case upcycled from a bookshelf found on the street. Each module is a series of potentiometers and I/O jacks with a wooden faceplate. The modules are connected to sockets on the main board and are held in place with thumbscrews so that the modules can be easily switched out. Each module can be connected to others using audio cables, the same way modular analog synths are connected.

The main board contains a Teensy 3.6 and a Teensy Audio Adapter creates the audio for the synth. Software that [Matt] wrote runs on the Teensy and allows the digital synthesizer to run in either monophonic or polyphonic modes. In polyphonic mode, the software creates digital copies of each module to allow the playing of chords. The Teensy scans up to eight module sockets and for each module that it finds, it reads the potentiometer value as well as the status of the I/O jacks. The keyboard buttons are converted to a control voltage which can be sent to any of the modules to create a melody.

[Matt] has created a great synth that combines benefits of both analog and digital synths together and the result is an inexpensive modular synth that can create some really cool sounds. Check out the videos after the break. In the meantime, take a look at this mess of wires and this article on a slew of open-source synthesizers.

Posted in 2018 Hackaday Prize, digital synth, Modular synthesizer, Teensy 3.6, teensy audio adapter board, The Hackaday Prize | Leave a comment