Typically, when you’re sitting on a plane on the tarmac, you switch your phone to flight mode while you’re sitting through yet another “quirky” (boring) safety video. You’ll watch some inflight entertainment, read the airline magazine if you get really desperate, and wonder if anyone ever buys those random watches for sale in the “duty free” section. Then, finally, upon landing, you’ll be connected back to the Internet and you’ll finally feel like you can breathe again.
Only, this time, you forgot to set your phone to flight mode. You’re sitting at 30,000 feet, and… your phone has signal? You’re online, and you’re getting notifications and emails just like you’re on the ground. You’ve accidentally discovered that your flight has an on-board cell tower.
[Aizysse Baga] worked with [Adelaide] on the Divacore record, which was to be released on a mini-CD. The original plan was to include additional CD+G data, featuring artwork to go with the music. CD+G, or CD+Graphics, was often used to display synchronized lyrics for karaoke releases, and stored data in formerly-unused subcodes next to the track start, track number, and running time data. This format allowed storing a slideshow of images with a resolution of 288 x 192 with a 16 color palette.
Note the quality difference between the 16-color CD+G and the 256-color CD+EG images.
The duo got handy with art and some smart dithering to get great 16-bit artwork packed in to the audio CD release, with the aid of a custom Python encoder. CD-TEXT metadata was thrown in for good measure. Then, the existence of the more advanced CD+EG became apparent. This was a 256-color extension to the CD+G format that was backwards compatible to boot. It was a format that was barely ever implemented on any commercial releases, and very little hardware could even display it. Naturally, Divacore had to have it. Much work was done to understand the Red Book documentation on the standard and figure out how to implement even higher quality artwork for the record.
After so much work to understand and implement the CD+G and CD+EG data, the question was whether it would survive the CD reproduction process for the final release. Thankfully, the final discs came out perfectly, and the full 256-color CD+EG artwork can be seen in all its glory if you happen to play Divacore on a Sega Saturn or a super-obscure Victor VS-G2 or VS-G3. Throw it in a less-sophisticated karaoke machine or something like an Amiga CD32, and you’ll still get to see the 16-color versions for your trouble.
We love to see ancient formats brought back to life, particularly those that never got their time in the sun. If you’re working hard to resurrect something the mainstream media world has forgotten, let us know on the tipsline.
iButtons are microchips housed in small, round, metal containers, and are similar to coin cell batteries in appearance. Among other things, they’re used for logging data in industrial contexts, particularly where it’s desirable to track parameters like temperature over time. [Geoffrey Wells] has worked with these sensors, and decided that the aging solutions for reading these devices are too cumbersome and out-of-date. Thus, he designed ChillPoint as a more modern solution.
As you might have guessed by the name, [Geoffrey] was inspired to build a rig specifically for inspecting iButton data loggers in cold chain logistics applications. It’s built around an ESP32-C6, which has a 1-Wire probe on the front for communicating with the target device. On contact, the reader dumps all the data, storing it on its own flash storage. The data can then further be accessed by connecting to the ChillPoint handheld device over its own WiFi access point, upon which it hosts a web UI for access. The handheld can be used for scanning iButtons single-handed, while a smartphone, tablet, or laptop can be used as a screen to monitor the results live.
The project is nearing completion, and [Geoffrey] says both the hardware and software will be open source once it’s all said and done. Anyone interested in adding a ChillPoint to their toolbox should keep an eye out for its upcoming CrowdSupply campaign.
How do you measure the inside of a cave? You could do a bunch of hard work with classic surveying gear… or you could just use a laser scanner. [9nl] did the latter, with a scanning rig of his own creation.
The build is based around an Ouster VLP-16 mid-range lidar sensor. It shoots out pulses of light and measures how long it takes them to bounce back in order to determine the range of objects in the vicinity, and thus can be used to great effect for 3D scanning tasks. For [9nl], though, the sensor had a serious limitation. Since it only had a 40-degree field of view, it wasn’t ideal for the desired application of scanning a cave. However, by building a custom rig that could rotate the sensor, [9nl] ended up with a rig that could 3D scan an area through a full 360 degrees. There’s nothing wildly complex involved, just some good old mechanical engineering—putting the sensor on a shaft and spinning it with a belt drive. Then it’s just a matter of processing the data correctly. The hard part is then getting the rig in and out of the cave without breaking anything.
There are plenty of off-the-shelf 3D scanning solutions that can do this work, but few of them come cheap. Plus, rolling your own teaches you a great many things as you hone your solution to your particular needs. Video after the break.
The heart of the build is an ATmega328P microcontroller, running off of a 32.768 kHz crystal. This allows the chip’s counters to neatly divide down the frequency to get a steady 1 Hz pulse for accurate timekeeping. Time is displayed on a vacuum fluorescent display (VFD) harvested from an old calculator. These displays need rather high voltages to run, which in this case are produced by a HV5812 driver chip and supporting circuitry. The display itself is neatly cradled in a pair of copper pipe elbows for a stylish look, with some addressable RGB LEDs present to provide some charming underglow.
Power for the device comes from a single AA battery, using a transformer-based low voltage converter. Alternatively, it can run off a USB 5 V power supply, which also charges the NiMH AA cell while available with the aid of an LM2576-ADJ buck converter.
The train was one of the game-changing inventions that defined the Industrial Age. No more would humanity rely on tempestuous animals to haul goods and passengers great distances across the land. Fire and steam came along to rapidly increase the speed of travel and transformed the very fabric of society itself.
To this day, the vast majority of train networks rely on the same basic principle—heavy locomotives and carriages running steel wheels on steel tracks. Yet, there is a curious alternative twist on this concept that sees trains of carriages riding on tires instead. But what would possess anyone to build a rubber tired train?
The build is designed around the keypad of the Nokia E52, a Symbian smartphone released in 2009—two years after Apple changed the game with the first iPhone. The phone keypad itself is laid over a custom PCB with Alps SKRK tactile switches corresponding to each individual key. Each is wired with a diode and the switches are scanned as a row/column array as is typical for keyboards. Reading the matrix is an ESP32-C6 microcontroller, which counts the keypresses and spits out the right letters over its Bluetooth connection to an attached smartphone or other device. Power is via a small lithium-ion battery, looked after by a TP4200 charger chip.
Overall, the keyboard works as you’d expect, allowing T9-style input to any compatible device that works with Bluetooth keyboards. [Jarrett] does have one regret, with the 0.98 N actuation force switches used leaving he keypad feeling a little mushy. The firmer 1.57 N switches were suspected to give a more satisfying response under thumb, which was a nice upgrade in the second revision build.
