Reaction Game with micro:bit

I built a simple game for Brown Dog Gadgets which will test your reaction time. The basic concept is this: A series of LEDs will light up in sequence, and when the fourth LED is lit you need to press the button. If you time it right you’ll get a point! When you get 25 points you’ll win the game! But wait! Each time you press the button successfully the game will speed up… and if you press the button at the wrong time you’re score will go down.

It’s a fun and easy build for the classroom or at home, and once again we’ve got a micro:bit controlling things. (Though it would be very easy to port this to an Arduino or another microcontroller.) We’re building on LEGO because that’s how the Crazy Circuits system works. We sometimes joke that these are PCBs or “Plastic Circuit Boards”.

After creating the Reaction Game (7 Segment Version) we came up with two variations, one that uses the build-in LED matrix on the micro:bit instead of our 7 Segment Display (the Reaction Game (LED Version)) and then we got even more minimal and built a paper circuit version with even less parts, the Reaction Game (Paper Version).

As always, we’re publishing these resources for those who purchase our kits, and also for everyone else. You are free to take the ideas and run with them, make your own thing, and while credit is always nice, supporting Brown Dog Gadgets by purchasing things helps us to continue offering these resources. I mean, in the last year I’ve published over 100 guides and templates for freeeeeee….. We appreciate your support!


Bit Board & micro:bit Powered Step Sequencer

The first guide I published for Brown Dog Gadgets was a step sequencer using their Arduino-compatible Robotics Board back in April 2020. You may also remember my WMSE sculpture that was a step sequencer, and I never did a write-up on it, but I also built a step sequencer for an interactive museum exhibit years ago, which was kid-tough and focused on sequencing as a form of programming.

Anyway, since it was nearly a year from the first Crazy Circuits step sequencer I think I should revisit it as a micro:bit project. So here’s a guide to building a Bit Board & micro:bit Powered Step Sequencer.

The code was written using Microsoft MakeCode for micro:bit, a block-based programming environment, which also supports Javascript and Python in text modes. It’s been interesting working in a block-based programming system, and I’ve gotten used to it in the past six months. I do really like the fact that you can toggle between block view and text view.

I’ve got a lot more micro:bit projects I’ve worked on in recent months, which you can check out in the Brown Dog Gadgets Project Database.


micro:bit Powered Xylophone

A recent fun project over at Brown Dog Gadgets is this automated xylophone controlled with a micro:bit… Check out the build guide.

Full instructions including code and some helpful tips on choosing a (toy) xylophone that will work for this project. (There’s maths and angles involved.) We’re basically controlling two servos to move a mallet left and right and then down (and back up) to strike a bar.

You can control it by playing it like a keyboard, just press the buttons, or you can program and store songs for automated playback later.

The (toy) xylophone isn’t really tuned very well, so we may be working on a larger project that uses a larger instrument. Also of note is the fact that the micro:bit out of the box can only handle three servos (without extra hardware) so we might switch to another board for the next iteration.

As usual, and since we’re using LEGO compatible servos, there are LEGO bits involved, which made building things quick and easy. (And don’t worry if you don’t have the needed LEGO parts on-hand, we’ve listed the parts we used and linked to where you can get them for cheap.)

Here are a few slightly out of tune songs…


Capacitive Touch on the micro:bit

Note: This post describes a hack to use capacitive touch on the micro:bit V1.5 but shortly after doing this, the micro:bit V2 came out, featuring real capacitive touch.

Out of the box the micro:bit has three touch pins which relies on a person touching not only the pin they want to trigger, but also to touch ground. Typically a person holds or touches something connected to ground, and then with their other hand touches one of the touch pins. This is how the Makey Makey works as well. It’s like capacitive touch (or capacitive sensing) but it’s not exactly. [It’s resistive touch.]

With a bit of experimentation we found that you can do capacitive touch on the micro:bit (sort of) so we wrote up a guide how to do it for the Brown Dog Gadgets Project Database called Capacitive Touch.

Two things to note about this one, first we are using the pins for analog input and while there are three more pins that do analog input on the micro:bit we found their performance to be a bit more unreliable than pins 0, 1, and 2. Of course since this is really just a hack, don’t let that stop you from using them. Second, there is no calibration done on the pins. For one of our Invention Board projects using capacitive touch we do a calibration at start so the pins know what is touched and what is not touched, as it can often change depending on the environment. The code we present does no calibration, but we’ll probably add that in the future.

As usual we’re using Maker Tape along with a LEGO baseplate and a Bit Board. (If you want a Bit Board to go with your micro:bit, we’ve got a Kickstarter campaign running now.) Capacitive touch is a lot of fun, and I’ve used it for many projects over the years. And yes, you can certainly incorporate other objects or surfaces besides Maker Tape.


Simple Level with Crazy Circuits

Here’s a super-easy micro:bit project that just uses a few Crazy Circuits LEDs, some Maker Tape, and a LEGO baseplate. It’s a Simple Level. Since the micro:bit has a built-in accelerometer we can easily check which way it is tilting just like an old fashioned level with liquid and an air bubble.

This project just uses five LEDs, but we outline how you could easily expand it to many more (and yes, we’ll probably build a larger one soon, as well as a multi-dimensional level.)

As always, there’s a diagram and more info as well as a look at the code. For each of these projects, if I can do a somewhat simple explanation of the code I think it’s helpful. You can certainly use the code and never dig into it, but I hope that people do. Kids (and adults) should learn to code if only for the fact that it can help understand how the world works, at least that’s how I view it.

Oh, I should mention that the Bit Board is now available via Kickstarter! And if crowdfunding isn’t your thing you can also get it direct from the Brown Dog Gadgets Shop.