Send Old-Fashioned Pager Messages With New-Fashioned Hardware

May 18, 2021 by Bryan Cockfield 5 Comments

In a world of always-connected devices and 24/7 access to email and various social media and messaging platforms, it’s sometimes a good idea to take a step away from the hustle and bustle for peace of mind. But not too big of a step. After all, we sometimes need some limited contact with other humans, so that’s what [EverestX] set out to do with his modern, pocket-sized communication device based on pager technology from days of yore.

The device uses the POCSAG communications protocol, a current standard for pager communications that allows for an SMS-like experience for those still who still need (or want) to use pagers. [EverestX] was able to adapt some preexisting code and port it to an Atmel 32u4 microcontroller. With a custom PCB, small battery, an antenna, and some incredibly refined soldering skills, he was able to put together this build with an incredibly small footprint, slightly larger than a bottle cap.

Once added to a custom case, [EverestX] has an excellent platform for sending pager messages to all of his friends and can avoid any dreaded voice conversations. Pager hacks have been a favorite around these parts for years, and are still a viable option for modern communications needs despite also being a nostalgic relic of decades past. As an added bonus, the 32u4 microcontroller has some interesting non-pager features that you might want to check out as well.

Thanks to [ch0l0man] for the tip!

Gaming Headset Gets Simple Wireless Charging

May 17, 2021 by Tom Nardi 9 Comments

Despite the technology itself being widely available and relatively cheap, devices that offer wireless charging as a feature still aren’t as common as many would like. Sure it can’t deliver as much power as something like USB-C, but for low-draw devices that don’t necessarily need to be recharged in a hurry, the convenience is undeniable.

Sick of having to plug it in after each session, [Taylor Burley] decided to take matters into his own hands and add wireless charging capability to his Turtle Beach Recon 200 headset. But ultimately, there’s nothing about this project that couldn’t be adapted to your own particular headset of choice. Or any other device that charges via USB, for that matter.

To keep things simple, [Taylor] used an off-the-shelf wireless charging transmitter and receiver pair. The transmitter is housed in a 3D printed mount that the headset hangs from, and the receiver was simply glued to the top of the headset. The receiver is covered with a thin 3D printed plate, but a couple turns of electrical tape would work just as well if you didn’t want to design a whole new part.

Once everything was in place, he then ran a wire down the side of the headset and tapped into the five volt trace coming from the USB port. So now long as [Taylor] remembers to hang the headset up after he’s done playing, the battery will always be topped off the next time he reaches for it.

Considering how many projects we’ve seen that add wireless charging to consumer devices, it’s honestly kind of surprising that it’s still not a standard feature in 2021. Until manufacturers figure out what they want to do with the technology, it seems like hackers will just have to keep doing it themselves.

Continue reading “Gaming Headset Gets Simple Wireless Charging” →

Hacker Spends A Few Cycles Upgrading An Under-Desk Bike

May 6, 2021 by Kristina Panos 12 Comments

Pandemic got you way behind on your exercise goals? Us too. But not [codaris] who bought an under-desk bike to get in a bit of cycling while banging away on the keyboard. The only bad thing about this bike is the accompanying app — it’s all-around weak and requires too many steps just to get to peddlin’. It pays to know thyself, and [codaris] knows that this will be a major de-motivator and made a desktop app that does it all, including/starting up as soon as the pedals start spinning.

[codaris] built a Windows application that displays workout data in real time and then saves the stats in a SQLite database after the pedaling stops. It took a fair amount of work to get there, logging the Bluetooth traffic during a ride and comparing that with Wireshark output from a live session to decode the communication between the bike and the app. Turns out there are six commands total, and [codaris] really only needs three — Connect, Start Workout, and Continue Workout.

The app displays the elapsed workout time, speed, distance traveled, and the current RPM. We love that it starts logging and displaying data as soon as [codaris] starts pedaling, because that would be a major goal for us, too.

There’s more than one way to hack a bike. [codaris] was inspired by [ptx2]’s excellent work to un-brick a much more expensive bike with a Raspberry Pi.

Thanks for the tip, [Jhart99]!

The Keyboard You Really Don’t Need Or Want

May 6, 2021 by Matthew Carlson 48 Comments

Most people think of a keyboard as a flat, vaguely rectangular thing with around 100ish different keys. A mechanical keyboard enthusiast would heartily disagree and point out various tenkeyless, 75%, 60%, or 40% keyboards that strip down the idea of what a keyboard is by taking keys out. [Stavros Korokithakis] takes that notion and turns it on its side by creating the five-button vertical keyboard known as Keyyyyyyyys.

This keyboard, or keystick, is designed to be onehanded and to be eye-contact-free. With just five keys, it makes heavy use of chording to output all the characters needed. It has a maximum of 32 possible states and taking out pressing nothing as a no-op leaves 31 possible key combinations. So [Stavros] had to get creative and laid out the letters according to their frequency in the English language. The brains of Keyyyyyyyys is the ubiquitous ESP32, emulating a Bluetooth keyboard while being wrapped in a simple 3d printed box. The code is hosted on GitLab.

If you don’t know how hard it is to learn a five-key chording keyboard from scratch, definitely check out [Stavros]’ video embedded below. “C’mon h.” We have heard reports that you can learn these things, though.

While this five-button keyboard may seem small, this two-button keyboard still has it beat by three keys. A one-button keyboard is just a morse code keyboard, and we are looking forward to a wireless Bluetooth version. Continue reading “The Keyboard You Really Don’t Need Or Want” →

Pool Temperature Monitor Mollifies Fortunate But Frustrated Children

May 2, 2021 by Kristina Panos 25 Comments

Who needs the city pool when you can party in the private pool over at Grandma and Grandpa’s house? No need to wait until Memorial Day weekend when it hits 90° F in the first week of May. But how can you placate grandchildren who want to know each and every day if it’s finally time to go swimming, and the pool itself is miles away? Although grandparents probably love to hear from you more often there’s no need to bother them with hourly phone calls. You just have to build a floating, remote pool temperature monitor which broadcasts every 30 minutes to an Adafruit MagTag sitting at kid’s eye level on the refrigerator.

Between the cost of commercial pool temperature monitors and all the reviews that mention iffy Wi-Fi connections, it sounds like [Blake] is better off rolling his own solution. Inside the floating part is an ESP32, a DS18B temperature sensor, and a 18650 cell. Most of the body is PVC, except for the 3D-printed torus that holds some foam for buoyancy. A handful of BBs in the bottom keep the thing pointed upright. For now, it shows the water temperature, but [Blake]’s ultimate goal is to show the air temperature as well.

Maybe it’s still too cold to swim, but the sun shines brightly most days. Why not harness its energy to heat up the water?

DIY Wireless Serial Adapter Speaks (True) RS-232

April 18, 2021 by Donald Papp 80 Comments

There is a gotcha lurking in wait for hackers who look at a piece of equipment, see a port labeled “Serial / RS-232”, and start to get ideas. The issue is the fact that the older the equipment, the more likely it is to be a bit old-fashioned about how it expects to speak RS-232. Vintage electronics may expect the serial data to be at bipolar voltage levels that are higher than what the typical microcontroller is used to slinging, and that was the situation [g3gg0] faced with some vintage benchtop equipment. Rather than deal with cables and wired adapters, [g3gg0] decided to design a wireless adapter with WiFi and Bluetooth on one end, and true RS-232 on the other.

The adapter features an ESP32 and is attached to a DB-9 plug, so it’s nice and small. It uses the ST3232 chip to communicate at 3 V logic levels on the microcontroller side, supports bipolar logic up to +/-13 V on the vintage hardware side, and a rudimentary web interface allows setting hardware parameters like baud rate. The nice thing about the ST3232 transceiver is that it is not only small, but can work from a 3 V supply with only four 0.1 uF capacitors needed for the internal charge pumps.

As for actually using the adapter, [g3gg0] says that the adapter’s serial port is exposed over TCP on port 23 (Telnet) which is supported by some programs and hardware. Alternately, one can connect an ESP32 to one’s computer over USB, and run firmware that bridges any serial data directly to the adapter on the other end.

Design files including schematic, bill of materials, and PCB design are shared online, and you can see a brief tour of the adapter in the video, embedded below.

Continue reading “DIY Wireless Serial Adapter Speaks (True) RS-232” →

Pedaling Away Under The Cover Of Your Desk

April 17, 2021 by Matthew Carlson 6 Comments

[Wayne Venables], like many of us, found himself sitting more than usual the past few months. Armed with a Bluetooth-enabled under desk exercise bike, he quickly found the app to be rather sub-optimal and set about reverse-engineering the protocol of his bike.

The first step was to use some apps on his Android phone to reveal the profiles on the bike, which showed his particular machine used a Nordic Bluetooth UART. This meant the only work would be decoding the stream of bytes coming off the wireless serial port. Using Wireshark and Bluetooth logs on his phone, [Wayne] was able to correspond the various commands to points in the video. There were still a few bytes that he wasn’t able to identify, but [Wayne] had enough to whip up a quick .NET app that can start a workout and log it all to a database. The code for his app is on his GitHub.

While [Wayne] doesn’t specifically name the bike he uses in this project, we tracked down the image he shows on his writeup to the Exerpeutic 900e. It appears to be discontinued but the reverse engineering approach should be usable on a range of Bluetooth-connected machines. This isn’t the first bike we’ve seen liberated by reverse engineering here at Hackaday. And we have a feeling it won’t be the last.