The first commercial devices to adhere to Microsoft's Jacdac standard, an open source bus-based plug-and-play specification for solderless connectivity between microcontrollers and peripheral devices, have hit the market — including a Jacdac add-on for the BBC micro:bit V2.
"Jacdac is a hardware+software platform for the plug-and-play creation and programming of physical computing systems," the Jacdac team at Microsoft explains of its creation. "A 'brain,' in this case a micro:bit V2, executes the user's program, while a set of modular accessories — or modules — provide additional capabilities."
On the hardware side, Microsoft has partnered with educational electronics specialist KittenBot to produce a "Jacdaptor" break-out board. A micro:bit V2 microcontroller development board is inserted into the top using its edge connector, then six three-pin Jacdac connects are provided at the bottom of the board — along with four crocodile-clip and conductive-thread friendly pin loops, mimicking those of the micro:bit itself.
To this, KittenBot has added a range of accessory boards including a switch, a rotary encoder, a potentiometer, light and magnetic field sensors, and an RGB LED ring — along with a "Hub" board, which has four Jacdac connectors on each side plus three ring-pins.
Jacdac isn't just positioned as an alternative to existing solderless interconnection approaches like Grove, STEMMA QT, and Qwiic — but its use of PCB edge connectors does make it cheaper to add to a board. Rather, Microsoft has developed a full software stack to go along with the hardware — with "services" describing how hardware, both Jacdac-specific and devices designed for the micro:bit alone, allowing easy access to connected hardware through unified code blocks in the MakeCode visual coding environment.
Microsoft has also teased a selection of Jacdac "brains" of its own design, none of which were commercially available at the time of writing — including an "IoT Brain" built around an Espressif ESP32-S2 and a "Brain RP2040" which features a Raspberry Pi RP2040 microcontroller.
More details on Jacdac itself are available on the project website; the Jacdac specification is available on GitHub under the permissive Creative Commons Attribution license for the hardware and MIT license for the software.
Anyone looking to build their own Jacdac device can follow Microsoft's instructions; those eager to try it out as a user can now purchase a Jacdac Kit for micro:bit V2 from Kittenbot at $59.90, excluding the micro:bit itself, or follow the instructions on the website to use a simulated version.