Mission Zero was a great success with four teams taking part.
Annie and Erin – Galaxy Girls
Alfie and Jake – Star Marshalls
Chloe and Rowan – Jelly Unicorn
Edward and Jack – Jupiter
All sent their code in to the ISS (International Space Station) via the
Trinket Mission Zero website and await news of it being run in December or January.
What did they learn?
- a little about how primary colours are coded in Python,
- that rounding values which have 10 decimal places to 1 decimal place speeds up the scrolling display so that their code would run in under 30 secs on the Sense HAT,
- that syntax, that is, commas, full stops, hyphens, underscores and brackets have to be absolutely correct,
- some basic Python Sense HAT commands, such as ‘display message’ and ‘display temperature in figures’.
We had great fun doing the activity with the help of Mrs, Ferencz-Clark, their teacher, and look forward to tackling more challenging Astro Pi missions next year!
Our Code Club and I are about to embark on Mission Zero from Astro-Pi. We’ll do the coding on an emulator: Trinket Mission Zero, but then I’d like them to be able to see their code run on a Sense HAT, just like the astronauts have up there, on the International Space Station.
Image from http://www.raspberrypi.org
Getting the Sense Hat working took a bit of time so I’ve described the process, and put some troubleshooting tips, in another post: Sense HAT – how to get your Sense HAT working
We’re already to begin on Thursday 19th October with a crew of eight year 5 and 6 pupils.
Let’s get started!
Always fit the Sense HAT while the R Pi is switched off – and ‘power off’ before removing it.
When you fit your Sense Hat on your R Pi2 or R Pi3 all the LEDS should light up but they should not stay that way. Once your Pi has booted up the LED lights should go out. HAT – What it means? Read: HATS – No, I’m not wearing one!
- If you don’t get any lights lit at all, the Sense HAT is probably not connected to the Pi properly. Make sure all the pins are going into the female header on the Sense HAT and press down firmly.
- If, as I got, all the lights are lit but don’t go out at all, there are several things that could be wrong:
- The Sense HAT still might not be connected properly to the Pi.
- The Sense HAT software might not be installed. In LX Terminal use:
- sudo apt-get update and let it do its stuff
- sudo apt get upgrade and ditto
- sudo apt-get install sense_hat
- The R Pi might not be recognising the Sense HAT. If so, go back into the Terminal and alter config.txt with the instructions below:
- sudo leafpad /boot/config.txt
- Scroll down to the bottom of the config file and type:
- dtoverlay = rpi-sense then Save and reboot your Pi.
- You need to have I2C enabled. This is automatically done on newer operating systems, such as Raspbian Stretch. If not :
- Go to the main menu,
- choose Preferences,
- choose Raspberry Pi Configuration,
- choose Interfaces
- and ‘Enable’ I2C and choose OK.
- Now you have a Sense HAT that lights up when you power up then becomes unlit during boot up. Try the Sparkles Activity ‘Make random sparkles on the Sense HAT’ from https://projects.raspberrypi.org/en/projects/sense-hat-random-sparkles
- If this works alright, you are now in business so start sensing temperature, etc. and think about getting some groups of children to do Mission Zero!
I expected this to be difficult to do – as you usually have to type something into LX Terminal to get your Pi to recognise the dongle – but it wasn’t. However it was not plain sailing. I couldn’t get the first wifi dongle, I bought, to work and spent ages, with other help, trying to get the software to recognise it, all to no avail. Either I’d got a dongle that wasn’t compatible with an R Pi or it simply didn’t work. I’ll never know!
However, once I’d bought the official Raspberry Pi wifi dongle it was totally straightforward!
That is, after I’d sorted out the amount of power needed. I connected my USB hub up to the Pi and switched on the hub’s power. Once I had done that it worked perfectly.
Now I can find recipes and cook with my little R Pi and HDMIPi screen in the kitchen and, also, sing very loudly to my heart’s content along with Choir! Choir! Choir! in the front room, where there’s no router. Aren’t you glad you’re not here!
PS If you want to use the dongle with a Pi Zero, (like I did because when I bought a Pi Zero with ready-soldered header from Pi-Supply they had no Pi ZeroWs) you need a:
USB to microUSB OTG* converter shim .
*OTG just means on-the-go
Yorkshire versus Lancashire PiWars gets a step closer!
The next stage in making the robot rover I’m constructing (with massive help from the Cam Jam people and their EduKit3) is to incorporate ‘power on the move’ for the PiZero.
As you read before in A robot rover using a PiZero – Part 1 the two powered wheels use 4 x AA batteries. However no independent power source for the Pi is included with the kit. You therefore have to choose and buy the one that suits you. Because I am using a piZero rather than a full-sized Pi, I can get away with a lower power battery source (which adds less weight) than you would need for the full-sized Pi. I therefore chose a 2200 mAh (milli Amp hours) DC 5V portable powerbank. These are meant for powering smartphones on the move. They are often called lipstick battery packs (because they’re like a large lipstick) and can be bought at high street discount stores.
I went to a trusted online Pi provider though, because I can’t afford to get it wrong and damage the rest of the set-up. Also, the Pi provider’s powerbank came with the micro USB cable to charge it up with (and link it to the PiZero).
Anyway, the powerbank came immediately and, after a charge-up of about 4 hours (using the plug from my smartphone), its light went out to show it was fully charged and it is working brilliantly. You just disconnect the cable and turn it around so the standard USB goes in the ‘OUTPUT’ on the powerbank and the micro USB goes into the Pi.
You can see my very rough video on YouTube here:Moving Robot
It cost £8.34 so I have now spent:
£47.04 + 4 AA batteries
on this project and I shouldn’t need to spend any more because the line following and the obstacle avoiding sensors are included in the kit.
The next job is to fit and code the ‘Line follower‘, so that the robot can follow a black line on a mat, and that will be in part 4.
Happy Raspberry Pi tinkering!
Yorkshire versus Lancashire Pi Wars here we come!
I’ve been working on getting my PiZero robot rover to start-up automatically when switching on the battery pack. Here are the instructions:
Get your robot running on start-up with a Raspberry Pi (I was using a PiZero)
Open the LXTerminal to amend the Cron table
sudo apt-get update
sudo apt-get install gnome-schedule
(I ignored some stuff that said I hadn’t got everything). When done type:
then choose the nano editor (usually no. 2)
and at the end of the document add:
@reboot python3 /home/pi/EduKitRobotics/4-driving.py
or your particular file (with path) instead of the part in red,
then choose Ctrl and X together, then (when you’re asked whether to save) Y and enter.
Then, when you reboot, your python code will start automatically. Shutdown and detach your robot from its monitor, etc.
Your robot will now start automatically when you attach a suitable power supply to your PiZero. (Don’t forget to switch on the battery that runs the wheels too!)
Scratch2 is a great upgrade to the Scratch programming language, Scratch1.4, that comes with your Raspberry Pi. If you have an R Pi3 you can now get a Scratch2 offline version.
To upgrade your version of Raspbian, so you can use Scratch2 offline:
Open the LXTerminal (see What I wish I’d known about Raspberry Pi if you’re not sure what the LXTerminal is) and type:
sudo apt-get update
and press Enter.
Let this do everything until you get pi@raspberrypi:~ $ back.
sudo apt-get upgrade
and press Enter.
Let this complete itself, as before, then type in:
sudo apt-get install scratch2
and when you look in the Programming menu Scratch 2 will be there!