On Wednesday, The Pi Hut launched two new products, which I covered here. The first of these, the MotoZero, is a new Zero-form-factor motor controller board that fits on top of any 40-pin Raspberry Pi. I’ve now had a chance to try it out and evaluate it’s potential, so here we go.
Aesthetics and hardware
First of all, it’s a very attractive board. The graphics on it give it a nice look and the white-on-black aesthetic is very pleasing to the eye. This is, obviously, not the be-all and end-all of a motor board, but it does show that Richard Saville (aka Average Man), the designer of the board, has clearly put a lot of thought and effort into it.
The board comes as a kit that you need to solder together yourself. This might put some people off, but honestly, there’s never been a better time to learn how to do it and this makes a good first timers’ project. It is simple enough to put together and the extensive assembly instructions included in the user guide are excellent, with photographs and detailed instructions of what order to do things in.
The L293D chips that come with the kit are an old technology, but very reliable. Each motor takes up three GPIO pins and there are terminal blocks supplied for up to four motors to be run from this single board. There aren’t very many boards out there that allow you to control 4 DC motors, and that makes the board very powerful.
One thing I did notice on the instructions is that there is no protection for the chips if you plug the battery power wires into the wrong holes. This shouldn’t happen, because the terminal block is labelled very well, but it is a consideration if the user of the board isn’t used to using batteries or isn’t very good at following instructions! This limitation is spelt out quite clearly in the user guide, but I would like to see (in a future board revision) some protection built in – accidents do happen after all.
Using the board
I soldered the board together (which took about 30-40 minutes, I wasn’t rushing) in the order recommended by the user guide, which I found to be very sensible and very detailed. I connected up four micro metal gear motors to the screw terminals and a four AA battery pack to the power terminal.
I used some code that Ben Nuttall had written using GPIO Zero to test the motors out. They worked perfectly. The motors were a bit slow, but I think that’s just the limitation of the motors rather than the controller board. I need to get hold of some wheels to fit the smaller motor axles to continue my robot-building project, but that’s just a simple matter of finding a source online.
Conclusion
For £10, this is a great, cheap little motor controller board. The ability to control four motors independently will no doubt appeal to those people who want the extra power and functionality for their robots. It’s designed well, has good backup documentation and I commend Richard for his work, and Jamie at The Pi Hut for offering to stock it.