Following that, the next phase of the build is to assemble the wheels onto the continuous rotation servos and calibrate them. Continuous rotation servos are, as the name suggests, different from regular servos in that they are made to be able to continually rotate in either direction rather than through a fixed amount and therefore are great for making controllable wheels. The instructions take us through connecting the servos and flashing some code to the micro:bit that sets the wheels to turn in different directions and stop using the A and B buttons.
There is a trimmer which needs tweaking while running the servos to ensure they are calibrated correctly, and stop when they are required to stop. This is pretty straightforward and clearly explained, with one small exception in the instructions: when in the online MakeCode programming environment, the blocks for controlling servos are listed under the ‘pins’ section, which took us a while to discover, having not used servos on the micro:bit before.
Once the servos are calibrated, the instructions move on to building up the chassis, which is accurately laser-cut out of green and white plastics. Everything fits together perfectly, and it uses the technique of nuts being captured in laser-cut spaces for bolts to thread into. This creates nice accurate joints in the chassis, but it can be quite fiddly to get the nuts held in place while holding loose components in the right position. We found using a small piece of masking tape to help keep the inserted nut in place can act as a very useful third hand.
As we assembled the chassis, we realised that there are mounting points and holes in the chassis that aren’t utilised. One set of holes align and allow a pen or pencil to be inserted all the way through the robot to the floor below, and this means you can play at programming the :MOVE mini to draw shapes. Other holes and mount points are there for use by a range of additional add-on kits that can be bought to expand the robot’s capabilities. These include things like a bulldozer attachment with a lifting shovel; there are also sensor add-on kits to turn the robot into a line follower and more.
Having finished the assembly of the :MOVE mini, it feels pretty sturdy in hand and our unit worked well, with the calibration of the servos being accurate so that both wheels turned at the same rate, meaning it would travel in a straight line when instructed to do so. While this is definitely a robot for smooth surfaces and not an ‘off-roader’, it worked well on a smooth carpet, lino, and wooden floors. At the end of the instruction manual, there are links and a QR code to take you to more example code and applications for the robot. Next on our list is to use another micro:bit as a radio control unit so we can drive it remotely, but it’s nice to see that there are lots of examples online of things people have done with theirs.
Kitronik £27.54 kitronik.co.uk
A great kit, suitable for beginners to both robotics and programming micro:bits. Younger builders might need a little help with assembly, but it’s a great-quality kit.