The Micro:bit is a very neat piece of hardware that, frankly, we don’t see enough of. Which made us all the more interested when [Manoj Nathwani] wrote in to tell us about the gorgeous 3D printed RGB LED lamp he created that uses the BBC-endorsed microcontroller to perform basic gesture detection. Purists will likely point out that an Arduino Pro Mini is tagging along to handle interfacing with the LEDs, but it’s still a good example of how quick you can get a project up and running with MicroPython on the Micro:bit.
[Manoj] used eight NeoPixel Sticks, a NeoPixel Ring, and a few scraps of perfboard to construct a three dimensional “bulb” to fill the void inside the printed diffuser. They’re chained together so all the elements appear as a single addressable strip, which made the rest of the project a bit easier to implement. It might not be pretty, but it gets the job done and it’s not like you’ll ever see it again once installed in the lamp anyway.
The Micro:bit and Arduino co-pilot live in the base of the lamp, and the single USB cable to provide power (and the ability to update the device’s firmware) is run out the bottom to give the whole thing a clean and professional look. For those wondering why the Arduino has tagged along, [Manoj] says he couldn’t get the NeoPixel libraries to play nicely with the Micro:bit so he’s using the Arduino essentially as a mediator.
Right now the only gesture that’s detected on the Micro:bit is a simple shake, which tells the Arduino to toggle the light show on and off. But in the future, [Manoj] plans to implement more complex gestures which will trigger different animations. As he explains in the blog post, gesture recognition with the Micro:bit is incredibly simple, so it should be easy to come up with a bunch of unique ways to interface with the lamp.
As [Paul Bardini] explains on the Thingiverse page for his “Micro:Bit Hand Controller”, the Bluetooth radio baked into the BBC’s educational microcontroller makes it an ideal choice for remotely controlling things. You just need to give it a nice enclosure, a joystick, a couple of buttons, and away you go. You can even use the integrated accelerometer as another axis of control. This is starting to sound a bit familiar, especially to gamers.
While it might not come with the Official Nintendo Seal of Quality, the 3D printable enclosure [Paul] has come up with for the Micro:Bit certainly takes more than a little inspiration from the iconic Wii “Nunchuck” controller. He’s jostled around the positions of the joystick and momentary buttons a bit, but it still has that iconic one-handed ergonomic styling.
In a particularly nice touch, [Paul] has built his controller around a Micro:Bit breakout board from SparkFun that allows you to plug the microcontroller in via its edge connector. This means you can pull the board out and still use it in other projects. The only other connection to the controller leads to the battery, which uses a two pin JST-PH plug that can easily be removed.
Thanks to this breakout board, the internal wiring is exceptionally simple. The joystick (the type used in a PS2 controller) and the buttons are simply soldered directly to pins on the breakout board. No passives required, just a few short lengths of flexible wiring to snake through the printed enclosure.
If you have a Raspberry Pi and have any interest in its peripherals, you may be familiar with the grinning pirate logo of the British company, Pimoroni. The Sheffield, UK based outfit first established a niche for itself as one of the go-to places for much of the essentials of Pi ownership, and has extended its portfolio beyond the Pi into parts, boards, and components across the spectrum of electronic experimentation. Their products are notable for their distinctive and colourful design language as well as their constant exploration of new ideas, and they have rapidly become one of those companies to watch in our sphere. On our way up to Newcastle for Maker Faire UK, we passed close enough to the Pimoroni HQ to be able to ask nicely if we could drop in and have a tour.
The Pimoroni HQ can be found in a nondescript unit with a discreetly placed sign on an industrial estate after a short drive through the city from the motorway. Inside it’s the same as thousands of other units, a set of offices at the front and a cavernous warehouse behind, except this one is filled with the kinds of goodies that get our blood pumping! And we’re told this toybox warehouse is soon to be joined by another nearby unit, as the Pimoroni business is expanding.
Our guide was the company co-founder Paul Beech, whose work you will be familiar with even if this is the first time you’ve heard his name; Paul was the designer of the Raspberry Pi logo! The company is not exclusive to that platform but it’s fair to say they have a strong connection with the Pi, starting in 2012 with as their website puts it: “One laser cutter and a kettle” on which they produced the first of their iconic PiBow laser-cut sandwich Raspberry Pi cases.
Kniwwelino is the latest in a line of micro:bit-inspired projects that we’ve seen, but this one comes with a twist: it uses an ESP8266 and WiFi at the core instead of the nR51 ARM/BTLE chip. That means that students can connect via laptop, cellphone, or anything else that can get onto a network.
That’s not the only tradeoff, though. In order to get the price down, the Kniwwelino drops the accelerometer/magnetometer of the micro:bit for a programmable RGB LED. With fewer pins to break out, the Kniwwelino is able to ditch the love-it-or-hate-it card-edge connector of the micro:bit as well. In fact, with all these changes, it’s hard to call this a micro:bit clone at all — it’s more like a super-blinky ESP8266 development kit.
So what have they got left in common? The iconic 5×5 LED matrix in the center, and a Blockly visual programming dialect dedicated to the device. Based on the ESP8266, the Kniwwelino naturally also has an Arduino dialect that students can “graduate” to when they’re tired of moving around colored blobs, and of course you could flash the chip with anything else that runs on an ESP8266.
We don’t have one in our hands, but we like the idea. An RGB LED is a lot of fun on Day One, and the fact that the Kniwwelino fits so neatly into existing bodies of code makes the transition from novice to intermediate programmer a lot easier. These things are personal preference, but WiFi beats Bluetooth LE in our book, for sheer ubiquity and interoperability. Finally, the Kniwwelino comes in at about half the manufacturing cost of a micro:bit, which makes it viable in schools without large manufacturer subsidies. They’re estimating $5 per unit. (Retail is higher.) On the other hand, the Kniwwelino is going to use more juice than its ARM-based competitor, and doesn’t have an accelerometer.
Kniwwelino is apparently derived from a luxembourgish word “kniwweln” that apparently means to craft something. The German Calliope Mini is named after Zeus’ daughter, the programmer’s muse. We’re stoked to see so many cute dev boards getting into the hands of students, no matter what you call them.
The BBC micro:bit single board ARM computer aimed at education does not feature as often as many of its competitors in these pages. It’s not the cheapest of boards, and interfacing to it in all but the most basic of ways calls for a slightly esoteric edge connector. We’re then very pleased to see that edge connector turned from a liability into a feature by [Fabien Chouteau] with his handheld console, he uses micro:bits preprogrammed with different games in the manner of game cartridges in commercial consoles.
The micro:bit sits in its edge connector on the underside of a handheld PCB above a pair of AAA batteries, while on the other side are an OLED display and the usual set of pushbuttons. It’s a particularly simple board as the micro:bit contains all the circuitry required to support its peripherals.
He’s coded the games using the Arduino IDE with a modified version of the Arduboy2 library that allows him to easily port Arduboy games written for Arduino hardware. It’s a work in progress as there are a few more features to incorporate, but the idea of using micro:bits as cartridges is rather special. There is a video of the console in action, which we’ve placed below the break.
The BBC micro:bit has been with us for about eighteen months now, and while the little ARM-based board has made a name for itself in its intended market of education, we haven’t seen as much of it in our community as we might have expected.
If you or a youngster in your life have a micro:bit, you may have created code for it using one of the several web-based IDEs, a graphical programming system, TypeScript, or MicroPython. But these high level languages are only part of the board’s software stack, as [Matt Warren] shows us with his detailed examination of its various layers.
The top layer of the micro:bit sandwich is of course your code. This is turned into a hex file by the web-based IDE’s compiler, which you then place on your device. Interestingly only the Microsoft TypeScript IDE compiles the TypeScript into native code, while the others bundle your code up with an interpreter.
Below that is the micro:bit’s hardware abstraction layer, and below that in turn is ARM’s Mbed OS layer, because the micro:bit is at heart simply another Mbed board. [Matt] goes into some detail about how the device’s memory map accommodates all these components, something essential given that there is only a paltry 16 kB of RAM in hand.
You might wish to program a micro:bit somewhat closer to the metal with the Mbed toolchain, but even if that is the case it’s still of interest to read a dissection of its official stack. Meanwhile, have a look at our review of the board, from summer 2016.
Among the plans for the platform are its localization into European languages, as well as a hardware upgrade and an expansion into the USA and China. Most excitingly from our perspective, the platform will henceforth be open-source, offering the chance of micro:bits finding their way into other projects. To that end thay have placed a reference design in a GitHub repository.
This is an interesting step for the little ARM board, and one that should take it from being a slightly odd niche product in one small country to the global mainstream. We can’t help however thinking that price is it’s Achilies’ heel. When it costs somewhere close to £13 in the UK, it starts to look expensive when compared to the far more capable Raspberry Pi Zero at £5 or a Chinese Arduino clone at about £2.50. Here’s hoping that economies of scale will bring it to a lower price point.