It might seem almost comical to our more fresh-faced readers, but there was a time when you could go into a big box retailer and purchase what was known as a “DivX Player”. Though they had the outward appearance of a normal DVD player, these gadgets could read various digital video file formats off of a CD-R or DVD-R, complete with rudimentary file browser. Depending on how much video compression you could stomach, a player like this would allow you to pack an entire season of a show or multiple movies onto a single disc. Before we started streaming everything online, that was kind of a big deal.
[Roberto Piva] got his hands on one of these early digital media players, a KiSS DP-500 circa 2003, and decided that it was too unique to send off to the recycling center. Not only was he curious about what made it tick, but he thought it would be interesting to try converting it into a Raspberry Pi powered streaming media player. One might say there’s something almost perverse about taking the carcass of one of these devices and stuffing it full of the same technology that made it obsolete in the first place, but who are we to judge?
Upon opening the vintage set top box, [Roberto] was immediately struck by how empty the thing was. He got the impression the device was a rush job, pushed out to capitalize on a relatively short-lived trend. Looking at it, we have to agree. It’s almost as though they got a deal on some old VCR chassis laying around in a warehouse someplace and decided to stick some (at the time) modern electronics in it. It even uses what appears to be a standard IDE optical drive rather than something purpose built.
[Roberto] hoped that he could tap into the player’s original power supply, but upon testing found that it wasn’t quite up to the task to reliably running a modern Pi. So into the cavernous enclosure went a powered USB hub, which he wired up to the original power switch on the player’s front panel. The original PSU couldn’t handle the Pi, but it does work nicely to spin up an IDE hard drive that he mounted to the top of the optical drive with zip ties.
This was enough to get a nice Kodi set top box that’s capable of pulling media from the Internet or the internal HDD, but [Roberto] has more plans for the future. He wants to try and get the optical drive working through a USB-to-IDE adapter so the device can come full circle and once again play burned discs full of video files, and mentions he would like to reverse engineer the front panel and IR receiver to control Kodi.
We are big fans of posts and videos that try to give you a gut-level intuition on technical topics. While [vas3k’s] post “Machine Learning for Everyone” fits the bill, we knew we’d like it from the opening sentences:
Machine Learning is like sex in high school. Everyone is talking about it, a few know what to do, and only your teacher is doing it.”
That sets the tone. What follows is a very comprehensive exposition of machine learning fundamentals. There is no focus on a particular tool, instead this is all the underpinnings. The original post was in Russian, but the English version is easy to read and doesn’t come off as a poor machine translation.
From the video below, [Mike Rankin] has been working down the scale in terms of powering and sizing his ESP32 builds. He recently completed a project with an ESP32 Pico D4 and an OLED display that fits exactly on an AA battery holder, which he populated with a rechargeable 14550. Not satisfied with that form factor, he designed another board, this time barely larger than the LIR2450 rechargeable coin cell in its battery holder. In addition to the Pico D4, the board sports a USB charging and programming socket, a low drop-out (LDO) voltage regulator, an accelerometer, a tiny RGB LED, and a 96×16 OLED display. Rather than claim real estate for switches, [Mike] chose to add a pair of pads to the back of the board and use them as capacitive touch sensors. We found that bit very clever.
Sadly, the board doesn’t do much – yet – but that doesn’t mean we’re not impressed. And [Mike]’s no stranger to miniaturization projects, of course; last year’s Open Hardware Summit badge was his brainchild.
As a society, we’ve largely come together to agree that laser pointers are mostly useless. They’re now the preserve of university lecturers and those destined to wind up in a jail cell for harassing helicopter pilots. Most pointers are of the diode-pumped solid state variety. However, [Zenodilodon] treads a different path.
Instead of the usual DPSS build, this pointer packs an optically pumped semiconductor laser, or OPSL. These lasers have the benefit of a wider selection of output wavelengths, and can be built to offer less variance in beam parameters such as divergence.
The build is an attractive one, with the pointer chassis being manufactured out of brass, with several components plated in yellow and rose gold. There’s even a sliding window to observe the laser cavity, which glows brightly in operation. [Zenodilodon] goes into great detail during the machining process, showing all the steps required to produce a visually appealing device.
[Out of Darts] runs as a store that sells all manner of tools and components for hopping up Nerf blasters, but they also sell complete original builds as well. The video showcases all manner of hardware, from powered backpack ammunition hoppers, to drain blaster shotguns and multirocket launchers. The workshop also contains 22 Prusa i3 printers that run 24/7 producing parts, barring breakdowns. Injection moulding, eat your heart out.
Things have come a long way since the old days of swapping in big springs to Hasbro blasters and crossing fingers that nothing breaks. 3D printing allows the home maker to produce just about any part imaginable without requiring advanced machine tools or special skills beyond the use of garden variety CAD software. It’s not the first time we’ve seen 3D printed Nerf blasters, and we’re sure it won’t be the last either. As always, tip ’em if you got ’em. Video after the break.
Firmware and software are both just code, right? How different could the code that runs Internet-scale distributed web stuff be from the code that runs a tiny microcontroller brain inside a personal hydroponics device? Night and day!
Ruth Grace Wong works in the former world, but moonlights as a manufacturing engineer with some friends. Their product had pre-existing firmware that contained (at least) one bug, and Ruth’s job was to find it. The code in question was written by the Chinese PCB engineer, who knew the electronics intimately but who had no software background, providing Ruth an opportunity to jump head-first into the rawest of raw embedded programming. Spoiler alert: she found the bug and learned a lot about firmware along the way. This talk follows her along the adventure.
“The code is very well documented, in Chinese” but the variable names are insanely non-descriptive. Similarly, while the PCB engineer knows full well what a 24C02 is, if you’re a software geek that might as well be Chinese. As you’d expect, web searches came to the rescue on both fronts.
The bug ended up hiding in a logical flaw in the PWM-setting code inside an interrupt service routine, and it kept the fan from ever coming full on. Once found, it was easily fixed. But getting to the point where you understand the codebase deeply enough to know where to look is four-fifths of the battle. Heck, setting up the toolchain alone can take a day or two.
If you’re a fellow software type, Ruth’s talk (embedded below) will give you a quick glimpse into the outer few layers of the onion that is embedded firmware development, from a familiar viewpoint. Give her quick and value-packed talk a watch! Grizzled hardware veterans will nod along, and maybe even gain a little insight into how our code looks to “them”.
Elliot Williams and Mike Szczys look at all that’s happening in hackerdom. This week we dive deep into super-accurate clock chips, SPI and microcontroller trickery, a new (and cheap) part on the microcontroller block, touch-sensitive cloth, and taking a home X-ray to the third dimension. We’re saying our goodbyes to the magnificent A380, looking with skepticism on the V2V tech known as DSRC, and also trying to predict weather with automotive data. And finally, what’s the deal with that growing problem of electronic waste?
Links for all discussed on the show are found below. As always, join in the comments below as we’ll be watching those as we work on next week’s episode!