Have you ever known what you wanted to say but couldn’t figure out exactly how to say it? For some individuals, that’s all the time. The gap between intention and action can be a massive chasm. [Pedro Martin] is trying to help bridge that gap with a Bluetooth RPM letterboard.
[Soma Mukhopadhyay] developed Rapid Prompting Method (RPM) for teachers to work with students with autism. Gentle physical cues can help individuals complete motor movements, which can be used as a communication mechanism by pointing to a letterboard. Students can eventually move onto an tablet, but some students see the light as sensory noise or might associate it with playtime.
[Pedro] hopes that his letterboard will be able to provide tactile feedback for each letter to strengthen the connection the teacher is trying to establish. The letter board is a 22 by 14 grid (308 total) of touch electrodes connected to three MPR121 12-channel capacitive touch sensors connected to an ESP32 via I2C. Additionally, 60 LEDS controlled by two shift registers are interspaced between the touch electrodes. As only one LED will be on at a given time, [Pedro] can use the shift registers in a row/column setup since the current draw should be small. A piezo buzzer serves as additional feedback for the student. The ESP32 emulates a Bluetooth keyboard, so the teacher doesn’t have to keep track of what the student is spelling and can focus on RPM.
[Pedro] encountered the usual slew of debugging problems, such as ground bouncing, captive noise, and Bluetooth wonkiness. The code, KiCad, and STL files are on the Hackaday.io project page. If you want more accessibility-focused keyboards, look at the RP2040-based Intellikeys we saw recently.
Have you ever felt the options for Morse code communication were too limited? Well, look no further than [marsPRE]’s open source WristMorse communicator that can connect over WiFi, can act as a Bluetooth keyboard or just be used as a Morse Code trainer.
[marsPRE] uses the M5StickC Plus as the base device and attaches a custom “hat” consisting of a 2.5 mm plug for a radio connection and two capacitive touch paddles that act as the Morse Code keyer. The add-on is housed in what looks like a custom 3D print and hangs off of the end of the M5StickC Plus, connecting the hat through an eight 0.1 inch pin header.
Using the M5StickC Plus allows [marsPRE] to focus on the software, providing different options for training, communication and even using the device as a Bluetooth keyboard. The two touch sensors allow for a semi automatic keying, with the top sensor used for long dashes and the bottom sensor used for short dashes.
[marsPRE] took inspiration from the Morserino-32 and has made the wrist morse code trainer open source software and available through GitHub for anyone wanting to take a look. Morse code may an old encoding method but it’s one that’s worthy of respect. You never know when you might need to send a message from your dreams or to translate spoken word Morse code.
Looking for a hands-free way to page through sheet music on an iPad, [The_Larch] came up with this simple Bluetooth input device based on the ESP32. The microcontroller just needed to have two switches wired into the GPIO pins, in this case the same heavy-duty plungers you’d find on a guitar pedal, and a USB bulkhead pass-through to provide power. Thanks to the excellent ESP32-BLE-Keyboard library, it only took a few lines of code to fire off the appropriate key strokes when the left or right button was pressed.
While undeniably a simple project from an electronics standpoint, the wooden enclosure [The_Larch] built is an interesting change of pace from the 3D printed fare we normally see around these parts. It started life as strips of oak reclaimed from an old kitchen table, which were laminated together to make a solid block. A large spade bit was then used to bore into the block to make a void for the electronics, and a second flat piece of oak was fashioned into a front panel.
Now here’s a stocking stuffer of a keyboard. The DecaTxt is the size of a deck of cards, and at first glance it looks like some kind of pocket Keno machine or other gambling or gaming apparatus. But that’s just because it’s so colorful. When you only have ten keys emulating a full keyboard, there’s bound to be some serious labeling going on, as there should be.
The DecaTxt is a Bluetooth 4.0 chording keyboard that’s meant to be used with your phone or whatever you want to pair it with. It was originally called the In10did, which stands for Input Nomenclature Ten Digit Interface Device. Catchy, no? At some point in the last ten years, this little guy went wireless and got a cooler name — the DecaTxt. Continue reading “Inputs Of Interest: DecaTxt Ultra-Portable Chording Keyboard”→
The Raspberry Pi holds incredible promise for those looking to build a small mobile terminal that they can take with them on the go, something you can throw into your bag and pull out whenever there’s some hacking to be done. But getting the diminutive Linux board to that point can take quite a bit of work. You need to find a suitably small keyboard, design a custom case, and wire it all up without letting any of that pesky Magic Smoke escape.
But a recent project from [remag293] might make things a bit easier for those looking to get their feet wet in the world of custom mobile computers. The boxy handheld device has everything you need, and nothing you don’t. A basic case, a short parts list, and an absolute minimum of wiring. What’s not to love? Even if you don’t make an exact clone of this device, it’s an excellent reference to quickly bootstrap your own bespoke terminal.
So what’s inside the 3D printed case? Not a whole lot, really. Obviously there’s a Raspberry Pi, a 3.5 inch TFT touch screen display, and a miniature keyboard. The keyboard is of the Bluetooth variety, and other than being freed from its enclosure and wired into the header on the display module for power, it’s otherwise stock.
As for the parts you can’t see from the outside, there’s a 3.7 V 4400 mAh battery pack and an Adafruit PowerBoost 1000 module to handle charging and power distribution. Beyond the big lighted button on the side (which you could certainly replace with something more low-key should you chose), that’s about it. When it’s all together, you’ve got a battery powered computer that’s ready for the road with a minimum amount of fuss.
If you’re looking for something that’s a bit larger, and more than a little unconventional, you could start by printing out a full cyberdeck. After all, if you’re going to build your own non-traditional portable computer, you might as well go all out.
Considering their hardware specification, graphing calculators surely feel like an anachronism in 2019. There are plenty of apps and other software available for that nowadays, and despite all preaching by our teachers, we actually do carry calculators with us every day. On the other hand, never underestimate the power of muscle memory when using physical knobs and buttons instead of touch screen or mouse input. [epostkastl] combined the best of both worlds and turned his broken HP-48 into a Bluetooth LE keyboard to get the real feel with its emulated counterpart.
Initially implemented as USB device, [epostkastl] opted for a wireless version this time, and connected an nRF52 based Adafruit Feather board to the HP-48’s conveniently exposed button matrix pins. For the software emulation side, he uses the Emu48, an open source HP calculator emulator for Windows and Android. The great thing about Emu84 is that it supports fully customizable mappings of regular keyboard events to the emulated buttons, so you can easily map, say, the cosine button to the [C] key. The rest is straight forward: scanning the button matrix detects button presses, maps them to a key event, and sends it as a BLE HID event to the receiving side running Emu84.
As this turns [epostkastl]’s HP-48 essentially into a regular wireless keyboard in a compact package — albeit with a layout that outshines every QWERTY vs Dvorak debate. It can of course also find alternative use cases, for examples as media center remote control, or a shortcut keyboard. After all, we’ve seen the latter one built as stomp boxes and from finger training devices before, so why not a calculator?
Part performance art and part social experiment, [mocymo]’s Smilemachine V6 helmet is as delightful as it is expressive. The helmet is made primarily from laser-cut MDF assembled around parts from a safety helmet. The display is an Android tablet with fine operation controlled by a Bluetooth mini keyboard, and the helmet cleverly makes use of the tablet’s ability to adjust the display to compensate for head tilt angle. It recently made an appearance at Maker Faire Tokyo, where the creator says the reception (especially by children) exceeded expectations.
There are several interesting things done with this device. One is the handheld controller, which is essentially a mini Bluetooth keyboard. To help allow fine control without needing to look down at the controller, the keyboard sits in a frame with some nuts and bolts used as highly tactile button extensions. By allowing the user to change the physical button layout (and setting up keyboard shortcuts on the device to match) the arrangement can be made more intuitive for the user. Some photos of this assembly are in the gallery after the break.
Another interesting bit is that despite a tablet being right in front of your eyes, it is possible to see out the front of the helmet while wearing it. The solution is completely low-tech: two mirrors form a periscope whose angle can be adjusted by turning a knob on the side of the helmet.
Version 1 of the helmet was started back in 2012; this is version 6 and [mocymo] is already filling out a to-do list for refinements. The nose area is uncomfortable, the angle of periscope is slightly off and the gearing needs to be reworked, among other things. We can’t wait to see Version 7. Video and gallery are embedded below.