Red Robotics’ RedBoard+ review – a fully-featured motor controller that isn’t afraid of high power and multiple functions

Neil Lambeth, of Red Robotics has recently released his first motor controller board for the Raspberry Pi. “Oh, not another one!” I hear you cry… Well, hold up there – this is one to pay attention to and it’s not ridiculously expensive, either.

TL;DR – Just buy one if you’re into robotics – it’s fantastic!

Capabilities

Coming in at £30/$38, the RedBoard+ is a HAT-sized controller board and it’s just packed with features:

  • It takes a battery input from 7V-24V and has reverse polarity protection.
  • It powers the Pi with a steady 5.2V, 3A power supply, meaning it will cope with a Pi 4, if necessary.
  • It has a 3.3 Volt 800mA Regulator.
  • It can control two sets of DC motors with two H-bridges on-board, capable of handling 6A per channel (12A overall!) This is one beefy controller.
  • It has a 4-Channel 5V level shifter for driving Neopixels, DotStars or other 5V electronics.
  • It breaks out three channels of an analogue-to-digital converter (one channel is used for battery monitoring)
  • It has one RGB LED on-board used for anything you like, but most useful as a battery warning light and/or an IP blinker (both scripts are included on the code repository).
  • It can directly drives up to twelve hobby servos (with a separate power input for large ‘robot’ servos).
  • It has one user-programmable button which is best used, as supplied, to shutdown or reboot your Pi with different hold-times.
  • An actual power switch to route battery power to the Pi and the motors.
  • Four I2C channels broken out onto headers.
  • Headers for serial communication (RX & TX).
  • Several Ground and Power pins.
  • A “really useful header” onto which you can plug an optional (but not yet available) OLED screen – this came in really handy, so thanks Neil for including one in my review pack!

Using the board

I have a robot I’ve been working on for ages with four powerful, 12V motors and a wooden chassis. It normally uses another motor controller board, but it makes an ideal test platform for the RedBoard+. Here it is in action (with thanks to the wife for doing the recording!):

I used a 10 x 1.2V rechargeable AA battery pack to power the Pi and the motors together, through the RedBoard+. To start with, the Pi kept rebooting and I wondered why… Panic set in! But it turns out that the batteries I was using were… not very good. Neil had pointed out that this could be the problem right at the beginning, but I spent a good few hours in denial before switching over to some Eneloops/Amazon Basics batteries (after which the problem miraculously went away!) Lesson learned: Always Use Good Batteries. It will also work with LiPo batteries, but I’m not that brave… yet! There’s even a test script in the GitHub repository that monitors battery power, tuned for LiPos.

For reference the offending AA batteries were these ones (EBL batteries which I got through Amazon):

Blummin’ things! Anyway!

All this time to test things out meant that I got to code a script to control the robot, with some help from Neil’s original test scripts and a program I’d written (for that other motor controller) that used Tom Oinn’s approxeng.input library (if you haven’t tried this out and you’re into robotics, give it a go – it’s lovely and is compatible with a lot of different games controllers.

Code and Scripts

The controller comes with a GitHub repository containing a simple-to-use library and various test scripts. These were instrumental in trying out the controller board and diagnosing the battery issue. If you get really stuck, and don’t want to install the software yourself, there’s even an SD card image linked to from the GitHub page. Neil’s really put a lot of thought into the user experience. The code he’s released works with both Python 3 (thank goodness) and Python 2 (shudder).

I’ve yet to put to the test the servo capabilities, but if you look at the bottom of this blog post, you’ll see an example of the board using servos as well as DC motors.

Conclusion

There are a lot of motor controllers out there, some more capable than others. If you want a controller board that does more than “just run a couple of motors”, I thoroughly recommend the RedBoard+. It’s good on price, fantastic on functionality and just oozes usefulness. Use the right batteries though – some just aren’t good enough to reliably run the Pi – stick with Eneloops or Amazon Basics or IKEA rechargeable batteries (which seem to all be the same base unit).

Put it another way: if I had to return this review unit (I don’t), I’d buy one in a heartbeat. When you consider the complexity of robotics competitions such as Pi Wars and the need to run more than just two DC motors at low speed, a controller that can handle a wide input range, can deliver high ampage to the motors and can also handle servos (including high-power servos) at the same time, RedBoard+ is what you need.

You can buy a RedBoard+ from Tindie.

Final bit

I’ll leave you with this demo video, shot by Neil himself. It shows all the functionality being used!

Potton Pi & Pints Raspberry Jam – Saturday, 23rd November, 2019 from 1pm-5pm

Fancy doing some Raspberry Pi, Arduino or micro:bit stuff in a relaxed, social atmosphere?
Fancy a chat with fellow geeky-type people?
Fancy finding out about the Raspberry Pi and other boards from first principles?
Then, the “Potton Pi & Pints” Raspberry Jam is for you!

What?

This is an informal family-friendly event from the same team that brings you the Cambridge Raspberry Jam and Pi Wars.
We start at lunchtime and encourage people to bring along their projects to Show and Tell or to come along and find out more about the Raspberry Pi, micro:bit or Arduino and what they can do. We set up some pi-topCEED Raspberry Pi workstations for general hacking, but you’re welcome to bring your own equipment along.

This event is an ideal opportunity to get some one-on-one help with setting your Pi up or to get assistance with an ongoing project.

If you want to drop in and learn something new, we supply some Raspberry Pis, worksheets and electronics so you (and your kids, if you have them!) can get hands-on.

Where?

The event is being held in Potton, a small town on the Bedfordshire/Cambridgeshire border, at The Rising Sun, a family-friendly, dog-friendly pub. Food is available all day and is of the pub-grub variety: generously-portioned and reasonably-priced. You can read more about The Rising Sun on their website.

We’ve arranged to use the upstairs function room which has tables and chairs and plenty of space for your projects or just for talking if that’s all you want to do.

This event is a real social for Pi enthusiasts and we’re hoping it will be nice and relaxed with none of the stress and frantic nature of the usual CamJam and Pi Wars! Kick back, unwind and do stuff with your Pi.

Equipment

We’ll be supplying a few Raspberry Pi workstations in the shape of pi-topCEEDs, keyboards and mice. All you have to do is come along. We’ll have some of our worksheets with us so there’ll be some activities for kids available.

Show and Tell

Feel free to bring your own Pi (or Arduino, micro:bit or other) project and whatever other electronic wizardry/gadgetry you happen to have. Please bring a 4-way adapter and extension cord just in case we run out! 🙂

Stay for a meal or a drink

At the end of the Jam (5pm-ish), feel free to join us for a meal/drink/chat. We generally go on into the evening! Everyone is welcome, so feel free to bring the whole family!

Safeguarding

Questions

Any questions can, as usual, be addressed to Tim Richardson (tim@potton.me.uk) and/or Michael Horne

Raspberry Pi and micro:bit robot maker Dexter Industries acquired by Modular Robotics

American educational robotics company Dexter Industries has been acquired by fellow American robotics company Modular Robotics. Dexter Industries, the company behind the excellent Raspberry Pi-based GoPiGo and the micro:bit-based Gigglebot as well as several others was merged into Modular Robotics back in July. Since then, they’ve been integrating their operations. Modular Robotics, based in Boulder, Colorado, make Cubelets – a fantastic way to get your kids into physical computing and robotics. You start off without a screen, assembling the blocks together, before moving on to using Blockly to program more advanced behaviour.

For now, both product lines are expected to continue, which is very welcome news for this blogger – the GoPiGo in particular is a brilliant robotics kit and the visual programming environment/software that goes with it (Bloxter) is first-rate, providing a user-friendly interface to help get you started with programming your robot. I reviewed the kit and the software a couple of years ago and it’s a great starting point.

It will be interesting to see how things progress as the companies innovate and work together to create new, exciting ways of encouraging kids of all ages to get into robotics.

The answer, my friend, is written on a Raspberry Pi 3 in this wind chime installation

At The Minories Galleries in Colchester, something is travelling on the wind. Sound artist Frazer Merrick has taken a set of wind chimes and connected them up to a Makey Makey board. The Makey Makey is then connected to a Raspberry Pi 3 which runs a Scratch script. The Scratch script interprets touches and movements of the chimes into additional sound, which are then player back through a set of headphones connected to the Pi. The effect is quite hypnotic:

Frazer has written up how he made it, and you can find the write-up on Instructables. You can read more about the project, and Frazer’s other work, over on his website.

 

Book review – Learn Robotics with Raspberry Pi (by Matt Timmons-Brown)

Sometimes, a book comes along that exceeds your expectations. When I saw that Matt Timmons Brown (“The Raspberry Pi Guy”) had teamed up with No Starch Press and that he had a very well-known and respected (though he’d never admit it) Technical Editor in Jim Darby, my expectations were sky high.

TL;DR – If you want a book on Raspberry Pi robotics, this is an excellent introduction, and much more.

Contents

Following a rather nice foreword from Raspberry Pi’s Eben Upton, the book is split into 8 chapters. They are:

  1. Getting up and running
    All about setting up your Pi and getting to a screen where you can start programming.
  2. Electronics basics
    A great chapter to help you understand basic components, how to light up LEDs, how to read button presses, etc. All basic knowledge for your journey into inputs, outputs and command-and-control.
  3. Building your robot
    Takes you through the physical construction using the components you’ve purchased. This includes making the Raspberry Pi and the robot run from the same power source using a cheap buck converter and running the motors using a cheap motor controller board.
  4. Making your robot move
    Includes sections on rudimentary, autonomous movement along a pre-defined route and, happily, turning your robot into a remote-controlled vehicle using a Wiimote.
  5. Avoiding obstacles
    A section about using an ultrasonic sensor to detect obstacles and autonomously drive away from them.
  6. Customising with lights and sound
    A fun chapter showing how to add LEDs and a speaker to your Raspberry Pi to make your robot more attractive and, well, loud!
  7. Line following
    This is all about using a purchased line detector module to follow a black line autonomously.
  8. Computer vision
    This chapter uses a Raspberry Pi camera module and OpenCV to detect and follow a coloured ball.

There are also appendices with a GPIO diagram, a guide to resistors and welcome tutorials on soldering and how to run code on start-up.

The tone of the book

I want to congratulate Matt and his editors on striking just the right tone with this book. It’s conversational, without being “chummy” and has detailed explanations, without getting so technical that you can’t understand anything.

Layout and quality

Remember those “high expectations” I mentioned earlier? As I said, this is a No Starch Press book, and it’s in full-colour, which really makes the diagrams “pop” out of the page. Congratulations to the publishers for producing a really excellent publication.

Here’s a sample page. You can see the quality I’m talking about:

Does it do what it sets out to do?

TL;DR: Yes.

The chapters of the book are well-ordered and their contents well-structured to take you, step-by-step, through the “bread and butter skills” you need as a robot creator. Each component is explained in detail (but not too much detail, as I said before) so that you learn why things work as well as how they work. In other words, it doesn’t tell you what to do to get something working without first telling you about the basic building blocks to get there. It’s a great approach, although it may prove too much for younger readers without adult guidance. I think that’s fine, though – robotics tends to be something which young people don’t get into until they are aged 11+, by which time the tone and content of the book should be within their grasp, albeit with a lot of concentration.

The remote-control section using a Wiimote is, of course, slightly basic (although it does get into using the on-board accelerometer to change the driving speed) but I’m glad it’s there – it will be something people will want to do.

The “meat” of the book, though, is those autonomous sections – distance sensing, line sensing and object following. These are excellent additions as it pulls you into the basic skills that you will need to take part in something like Pi Wars and also prepares you for taking your skills into professional industry.

Conclusion

This book really is an excellent introduction to Raspberry Pi robotics but is also for people who have built their robot already and want to move into autonomous sensing and movement. It is well-written and very accurate, thanks to Matt’s efforts and Jim’s technical editing and is stunning to look at, thanks to No Starch Press. Bravo to all concerned!

Buying it

In the UK, you can pick it up for around £17 at Amazon.

In the USA, you can pick it up for around $25 from No Starch Press (or Amazon).