Jacdac - First Impressions

Jacdac is a modular prototyping/educational electronics system and protocol. This isn't Microsoft's first foray into this world. Some of you will I'm sure remember the .Net Gadgeteer system. 

In Jacdac, Microsoft have clearly learnt from their experiences of .Net Gadgeteer and produced an easy to use and more child friendly system, that can make use of the micro:bit, as well as other 'brains' using a selection of adaptors.

The Kit I was kindly given to play with is the Jacdac Starter Kit A, which is available from Amazon.com and elsewhere.

What's in the box?

The kit includes: 

• push buttons, 
• a rotary encoder, 
• a slider (pot), 
• a Neopixel (multicolor LED), 
• a bundle of Jacdac leads,
• a Jacdac micro:bit interface board,
• a Jacdac expander (if you need more connections)

Each module (even a key-switch) has a tiny microcontroller to handle communication, as well as indicator LEDs that show connection and communication is working. 

Getting Started

To get started, I followed this tutorial. Note that this kit only works with version 2 of the micro:bit (the one with the bumpy edge connector).

Follow each step carefully. I hadn't noticed that the slide switch on the micro:but adapter was in the wrong position, This needs to be set to the position labelled Jacdac.

Follow the tutorial, but in overview the steps are:

• Create a new Makecode project
• Install the Jacdac extension
• Download the new Makecode program onto your micro:bit
• Start plugging stuff in

Connectors

The Jacdac connectors are reversible (like USB-c) and great for kids -- at least compared to wrangling open the jaws of alligator clip leads. The kit helpfully supplies a selection of lengths of lead.

The leads can be connected to any of the ports on the micro:bit adapter and can be daisy-chained together, making the wiring simple and un-cluttered.

If everything is setup correctly, then when you connect one of the modules to the adaptor, the module will appear in the left-hand side of the Makecode editor window.

Here you can see that Makecode has become aware of the Slider and LED ring devices.

You don't yet have any blocks you can use, but if you click on the ADD BLOCKS button, blocks for using the devices connected will appear in the Modules category of blocks in Makecode.

The screen capture above show a program that sets the brightness of the LED ring depending on the position of the slider.

Conclusion

Overall, I really liked using this hardware. The quality is excellent and leverages the already popular micro:bit and Makecode nicely.

Pros

• Easy to use and child friendly
• High quality

Cons

• There is no concept of a circuit. It's modules plugged together. In extremis, you could just leave everything in the kit plugged together all the time. You are really just choosing which modules to use and which to exclude.
• A little on the pricey-side. But, looking at the design, I can see why it has to cost what it does. 

Who's it For

I think, that as an educational tool, this is an excellent system. Kids and educators will have a lot of fun with this.

It may also have some use during product design, as a way of producing a functional prototype very quickly, allowing usability to be assessed.

Who isn't it for

I don't see this being used by electronics hobbyists and makers. It's too expensive to be used in permanent installation of projects. Arduino and clones coupled with solderless breadboard migrated onto soldered prototyping board are a more realistic prospect.

Even though it's good for making prototypes from a user interface perspective, it of no real value in prototyping an electronic design. No electronic engineer is going to couple a microcontroller with every LED or push-button in an embedded system.