I recently installed and tried out “Cayenne“, which is an Internet of Things platform for the Raspberry Pi. You hook sensors up to your Pi, create the relevant boxes on Cayenne and then you can see readings over the Internet. Not only that, you can also remote-desktop to your Pi and control the GPIO pins via their excellent web or mobile app. Overall, it was a very positive experience and I was able to use all the functions available with little to no bother. Thoroughly recommended if you want to do this kind of thing with a very nice interface. Take a look.
Gus, over at Pi My Life Up, has written an extensive tutorial on installing and using it and gives his reaction to the service. I highly recommend reading through it.
Jamie Bailey from Initial State (a brilliant IoT API website) has been in touch again. This time, he’s published a really fun tutorial in which you create a set of scales from a Wii Balance Board and hook it up to a Raspberry Pi 3 (or other Pi with a Bluetooth dongle). You then use the Initial State website to graph the results and get it to send you an SMS each time you take a reading. Take a look here.
This time on The Pi Podcast, the guys cover the latest news, including an intriguing (and successful) attempt to get Minecraft-alike game Minetest running on the Pi. Should be interesting to see if we can get Python integration on that as well as Minecraft seeing as development on the Minecraft Pi Edition platform seems to have stalled.
Interviewed on this episode is John Cole, founder and CEO of USA-based Dexter Industries.
On a fresh (read: a bit chilly) Saturday morning, I drove up the A1 to Peterborough to attend the Peterborough Raspberry Jam, organised by Hannah Mills & Mike Mills (no relation!). It had been a while since I attended a Jam that I hadn’t organised, so I was really looking forward to it. I was not disappointed!
TL;DR: I had a great time, there were lots of people there and plenty of fascinating projects and products as well as great talks and workshops.
Once I’d eventually found the right building (my sense of direction got it wrong!) I was warmly greeted by Hannah who let me have a timetable and some extra times to cover various duties and a Jam Maker badge. I proudly wore it all day! So nice to be helping out at someone else’s event!
To start with, I browsed around the foyer which was host to their Show and Tell exhibits and Marketplace. While not as large as the facilities at CamJam’s Institute of Astronomy, this was a great space filled with Pi-related stuff and helped to generate a real buzz.
First up was Steve Upton and his awesome LED display screen. This has lots of bright LEDs in strips which make up a pixelated screen onto which various messages and games can be displayed. Here’s Steve (left) and Hannah (right) as she plays Space Invaders!
Hannah playing Steve Upton’s Space Invaders
Next was Pi Top. Jesse was introducing a child to the wonders of the Pi Top’s operating system and multi-player online game designed to educate children in algorithms and coding with exploratory play.
Pi Top
Next along was Ragworm. It was great to see Connor and Stacey again and their selection of circuit boards.
The FUZE team was here with their rugged all-in-one keyboard/Pi solutions. They’ve got some exciting things coming up soon (which I can’t tell you about) so keep an eye on the blog for more about that in the next couple of weeks.
Fuze
David Saul was next in line. He was displaying some of his great display add-on boards for the Pi but what really caught my eye was the multi-language word clocks controlled by the Raspberry Pi Zero.
David Saul’s word clocks
The major vendor at the Jam was Rapid Electronics (The Pi Hut were unable to attend due to a family emergency). I was impressed by their selection of products and their friendly manner. I particularly liked the bargain bins down the bottom full of hackable goodies. I picked up a make-it-yourself mobile phone kit that I’d wanted for ages.
Rapid Electronics Marketplace stand
Robin Newman, who attends lots of Jams and always has something new to show, was next. He had a Pimoroni Flotilla robot to try out. I’m still not sure about all the cables, but it was great to see it ‘in action’.
Robin Newman’s Flotilla robot
He also had his Sonic Pi demonstration equipment (although I didn’t get a chance to find out what it was all about – he was very busy!)
Robin Newman’s show and tell
Next around the room was Digital People in Peterborough, an organisation that tries to bring technological people in the city and surrounding towns together. As part of their display, Stuart Elmore was displaying his voice-activated, talking mirror project. This used the Google Voice API to analyse vocal commands and provide responses. At the moment, it’s a few phrases but Stuart hopes to expand it to have some kind of artificial intelligence.
Stuart Elmore’s voice activated talking mirror
Just inside the entrance, there were two large Show and Tell exhibits. The first, which I didn’t get a photo of (doh!) was a set of real full-size, traffic lights using salvaged parts which would otherwise have been headed for land-fill. A Pi detected the pedestrian button-press and then activated the traffic lights sequence. Great stuff!
I’ve left the most fun exhibit until last. Taking inspiration from Pi Wars 2015, maker Brian Corteil has created “Micro Pi Noon”. In it, teams use mini robots to fight each other and burst a balloon attached to their competitor. You can see Brian explain the rules and a (very) quick duel between two house robots in the video below:
Here’s Brian with his creation:
Micro Pi Noon with creator Brian Corteil
And here’s the Hitchin Hackspace boys with their custom competitor robot:
It was also great to catch up with lots of people:
Hilary, Steve and his daughter
In the afternoon, I gave a presentation on HATs and Add-On Boards. Following Brian’s talk on robotics, I bravely switched my laptop on… and was promptly faced with a Blue Screen of Death. Darn you, Windows! So, I switched to my backup plan – a printed copy of my presentation placed on the ‘visualiser’!
Thanks to a couple of people in the audience who took and tweeted these snaps!
After that, it was straight into the workshop room to prepare for the session I was running using the first CamJam EduKit. I had 15-18 people in the room wiring up circuits and programming their Pis using RPi.GPIO from Tim Richardson’s EduKit worksheets. This was the first workshop I had ever run and (despite me being nervous) it seemed to go pretty well. I certainly learnt a lot about what works and what doesn’t. Next time, we’ll use different material specifically designed for a 45-minute burst of activity. Less reading, more doing, is how the lessons can be summed up!
The CamJam EduKit workshop
I had about an hour after the workshop so I helped to tidy and pack everything away. Big thanks to Mike Mills for loaning the Pi workstations to the Jam – it’s really great kit!
After that, it was into the centre of Peterborough to the Argo Lounge for a bite to eat with some of the exhibitors, speakers and organisers. Very nice it was too – my first try of tapas!
I had a really great time – big thanks to Hannah and Mike for making it seem so effortless and creating a relaxed, fun atmosphere. Hopefully it won’t be too long before they do the next one!
The MagPi has just published a fun little tutorial which gives you the code for “The Bedrock Challenge”. In Minecraft Pi Edition, the Python code generates a random, invisible arena with holes in the floor that you must avoid to prevent yourself from plummeting to your death. The only help you have is an LED that lights up when any of the blocks surrounding you are empty air. The code and wiring diagram for the LED is available here.
David Whale lent me a copy of this book for review. Thanks David!
The author
Richard Grimmett is an Idaho-based electrical engineer who has worked in the radar and telecommunications industry and now teaches computer science and electrical engineering. One of his hobbies is robotics and he has used his not-insubstantial knowledge in that area in his book Getting Started with Raspberry Pi Zero, published by Packt.
The content
To start with when I opened the book, I was thinking “Same ol’, Same ol'” as it started with the standard information on setting the Pi up and getting an image written to the SD card. It’s very well-done, well-written, but nothing I haven’t read before. However, I was then pleasantly surprised with what he then did. He moved straight on to a crash-course in Python, programming constructs and libraries and an introduction to the GPIO, including hooking up various sensors. My surprise stemmed from the style and quality of the writing as well as the commitment to getting the ‘good stuff’ up-front and early. Several Pi books I’ve read spend a great deal of time on very basic stuff, but Grimmett wasn’t afraid to get stuck in with GPIO programming virtually immediately.
The book gets better because the author has recognised one the central lessons of getting people enthused with the Raspberry Pi: Robotics! He has written in-depth chapters on building wheeled robots and also a walking robot. He goes into the fine detail, such as which components you need to buy, and uses both a simple H-bridge chip as well as an off-the-shelf motor controller board, in this case the RasPiRobot Board v2 (version 3 is now out, but I’m sure the instructions won’t differ).
The following two chapters deal with adding voice recognition and synthesized speech to your robot and hacking an existing remote-controlled device such as an RC car or robotic dinosaur.
There is then an intriguing chapter on creating a robotic hand from 3D printed parts with servos. The hand is then used to play a game of rock, paper, scissors, together with a short piece on image recognition using OpenCV.
The final chapter deals with adding a Zero to a quadcopter. This is the least in-depth chapter (as the subject is rather large) with most of the chapter dealing with using MAVProxy to plot flightplans.
Summing up
Overall, the book is extraordinarily well-written and well-researched. Grimmett has obviously done all of these projects himself (as opposed to just doing them in theory) and has taken copious photographs, and created lots of circuit diagrams, to go with the written material. His background gives you the confidence that he knows what he’s talking about and the projects are interesting, well-thought-out and well-documented. I have a few minor caveats:
The projects are not necessarily Pi Zero-specific, although with these projects you might find size is a relevant factor. This isn’t a bad thing, actually, as it means the book is relevant for all Pi owners, not just owners of the Zero. The book title is not misleading as such – I just thought it was worth pointing out as hopefully it will mean the book can be ‘pushed’ to all owners.
The parts and the shops used to procure them are USA-based, although I’m sure you can find them in the UK or import them without much hassle.
The book is printed in black-and-white. It would really benefit from colour photos, although they are available to download in colour from the Packt website. When you’re dealing with circuit diagrams and photographs of circuits, colour (although expensive) would add significant value to the book.
Circuit diagrams could be clearer, as could the photographs of the circuits – most of this is down to the lack of colour.
Quadcopter chapter wasn’t as interesting to me compared to the rest of the book and could easily be left out. I felt he could have gone into a bit more detail as to how the Zero could’ve actually been used (or not!) to control the quad.
The book is priced at £19.99 (for printed) and slightly less for just the e-book. I would say that this is a little high, considering the lack of colour, but I do understand that Packt’s publications tend to be a little more expensive as they are a smaller publisher. I would not object that much to paying that amount for this book – it’s detailed and thorough enough that you feel like you’re getting value-for-money. In terms of the colour, I do know that Packt don’t generally print in colour, but I feel it’s something they should consider for a product of this quality.
Addendum: I’ve since been contacted by the publisher, Packt, who have told me that when you buy the paper-based book, you get a free copy of the colour e-book as well. This helps to redress some of the issues with lack of colour.
Rating: 8.5/10 for UK people, 9/10 for USA people (just because of the USA-based sources of components).
You can buy the book from Packt or from Amazon (where you can use the Surprise Me function to see some sample pages).
