Long ago when digital portables where in their infancy, people were already loath to type on tiny keyboards, stylus or not. So Palm made a sweet little portable keyboard that would fold up and fit in your cargo pocket. And what do we have now for luxury typing on the go? Rubber roll-up jelly keebs? That’s a hard no from this scribe.
There’s really not much to this build, which relies on the Adafruit Feather nRF52840 and will readily work with Palm III and Palm V keyboards. Since the PPK is RS-232 and needs to be TTL, this circuit also needs a voltage level inverter which can be made with a small handful of components. We love that there’s a tiny hidden switch that engages the battery when the adapter clicks on to the connector.
The schematic, code, and STL files are all there in the repository, so go pick up one of these foldy keebs for cheap on the electronic bay while they’re still around. Watch the demo video unfold after the break.
By now most readers should be used to the phenomenon of taking almost any microcontroller and coaxing it to run a port of the 1990s grand-daddy of all first-person shooters, id Software’s Doom. It’s been done on a wide array of devices, sometimes only having enough power for a demo mode but more often able to offer the full experience. Latest to the slipgate in this festival of pixelated gore is [Nicola Wrachien], who’s achieved the feat using an nRF52840-based USB Bluetooth LE dongle.
Full details can be found on his website, where the process of initial development using an Adafruit CLUE board is detailed. A 16MB FLASH chip is used for WAD storage, and an SPI colour display takes us straight to that cursed base on Phobos. The target board lacks enough I/O brought out for connection to screen and FLASH, so some trickery with 7400 logic is required to free up enough for the task. Controls are implemented via a wireless gamepad using an nRFS1822 board, complete with streamed audio to a PWM output.
The result can be seen in the video below the break, which shows a very playable game of both Doom and Doom 2 that would not have disgraced many machines of the era. This was prototyped on an Adafruit Clue board, and that could be the handheld console you’ve been looking for!
When they first came to market, many detractors thought that smart watches would be a flop or that there wouldn’t be much use for them. Over the past few years, though, their sales continue to increase as people find more and more niche uses for them that weren’t previously considered. The one downside to most of these watches is unsurprisingly their lack of openness and hackability, but with some willpower and small circuit components there are a few options available for those of us who like to truly own our technology.
This smartwatch is the SMA Q3, the next version of this smartwatch that we saw at the beginning of last year. Like its predecessor, it boasts a sunlight-readible display powered by a Bluetooth SoC, but this time uses the upgraded nRF52840. All of the standard smartwatch features are available, but this version also includes SWD pins on the back, and additionally has support for Bangle.js and can run some of the apps from the app loader. Some details still need to be worked out for this specific hardware, but there are some workarounds available for the known problems.
The project is also on Kickstarter right now but is well past its funding goals. We’re excited to see adoption of an open-source smartwatch like this, and to that end all of the hardware details and software are freely available on the project’s page, provided you can order some of the needed parts from overseas. If you’re looking for something a little more BASIC, though, we have you covered there as well.
There are quite a bit of mixed emotions regarding working from home. Some people love it and are thriving like they haven’t before, but others are having a bit of a hard time with it all. [Brandon] has been working from home for the last 12 years, but even after so many years of managing this type of work culture, he admits that it can still be a little stressful. He says he doesn’t take enough time in between tasks to simply relax and to breathe a little and the day-to-day minutia of his work can drive his stress level up if he doesn’t take some time to calm himself. He figured he could make something to monitor his stress level and remind himself to take a break and the results are pretty impressive.
[Brandon] used an off-the-shelf chest strap heart rate monitor to save himself a bit of time in trying to build his own. The device sends heart rate data to an nRF52840 over Bluetooth and then pushes the data to the cloud using a Blues Wireless Notecard. The Notecard also offers data encryption which gave [Brandon] some added peace of mind knowing his biometric data wasn’t floating around in the cloud without any sort of protection. This certainly isn’t medical-grade encryption, but it gave him a bit of comfort, nonetheless. All that data is processed in his custom-designed web app and when the appropriate thresholds are reached, he sends a text message to himself using Twilio reminding him to relax and unwind for a bit.
For his next iteration, [Brandon] might try making his own heart rate monitor. But until then, stay safe everybody, and remember to take a break whenever you need it.
Make the move to a split keyboard and the first thing you’ll notice is that you have all this real estate between the two halves. (Well, as long as you’re doing it right). This is the perfect place to keep your cat, your coffee cup, or in [Jacek]’s case, your fantastic DIY trackball mouse.
Don’t be fooled by the orange plastic base — all the electronics are rolled up inside that big sexy ball, which [Jacek] printed in two halves and glued together. Inside the ball there’s an Adafruit Feather nRF52840 Sense, which has an onboard accelerometer, gyroscope, and magnetometer. As you’ll see in the video after the break, the Feather takes readings from these and applies a sensor-fusing algorithm to determine the ball’s orientation in 3D space before sending its position to the computer. To send the click events, [Jacek] baked some mouse buttons into the keyboard’s firmware. Among the other Feather sensors is a PDM MEMS microphone, so detecting taps on the ball and translating them to clicks is not out of the question for a future version.
Here comes the really clever part: there are two reed switches inside the ball. One is used as a power switch, and the other is for setting the ‘up’ direction of the trackball. The ball charges wirelessly in a 3D printed base, which also has a small neodymium magnet for activating the reed switches. Check out the demo after the break, which shows [Jacek] putting the trackball through its paces on a mouse accuracy testing program.
The pull chain switch is connected to an Adafruit Feather nRF52840 Express that’s emulating a Bluetooth keyboard. Firmware-wise it sends command + F6, which triggers an AppleScript that manually exits and and all Zoom calls and kills Chrome tabs pointed to meet.google.com. He’s using Apple’s hotkey wizard Alfred, but this could be handled just as easily with something like AutoHotKey.
Pull chain switches are neat little mechanisms. The chain is connected to a cam that engages a wheel with copper contacts on half the outside. When you pull the chain, the wheel moves 90° and the wheel contacts connect up with the fixed contacts inside the housing to make a connection. Pulling the chain again moves the wheel which slides to the half without the contacts. Check it out in the video below.
Making an event badge is hard work. Making a single prototype badge is hard enough, but the whole process of sourcing components and coordinating manufacture for hundreds of badges on a shoestring budget with the looming deadline of the event and its expectant attendees is a Herculean task.
[Uri Shaked] is one who bears the scars of producing an event badge, and he’s written a fascinating account of his experience. The conference in question was Aramcon 2019, a private tech event in Israel, and the badge has an nRF52840 driving an e-ink display, multi-colour LED, and an audio codec, with a set of full-size keyboard keys as user input. Since the nRF chip supports mesh networking, the idea was to produce a badge capable of streaming audio across the entire event.
We follow the team through nail-biting months of prototype boards, reversed connectors with last-minute cable bodges, compatible parts that didn’t turn out to be quite so compatible, and wrong footprints, and see them arriving at a badge which worked, but without the audio they’d hoped for. Along the way they came up with a clothes-pin-based programming jig which would surely have merited its own Hackaday write-up had they covered it on its own. Demonstrating the mesh networking by turning a whole auditorium’s worth of badges LEDs yellow was their reward, and we can see they’ve produced a very creditable badge. We particularly like the use of keyboard key switches, and we commend them for planning a life for the badge after the event.