An HDMIPi for Geek Gran

Am rather pleased about this!  For the first time in my life I’ve assembled something more complex than Lego City (5-12 years). The instructions at Cyntech assembly guide were excellent and I only got stuck when you had to attach the ribbon cable to the driver board.

You needed to insert the ribbon cable underneath the black tab. I thought it might go between the tab and the white plastic of the connector, but no, it went underneath.

hdmipi

I tested HDMIPi with a games console and it worked but can’t test it with the Raspberry Pi as I need another power supply. I thought my R Pi would work with the power from my USB hub but alas the R Pi seems to need something attached into its micro USB power socket to function.

Anyway, when I get to Leeds Raspberry Jam tomorrow night I’m sure someone will be able to lend me a power supply and then I’ll send for one straight away.

This little 22.5 cm (9″) screen is going to be so useful when I take the R Pi2 to Code Club . And when I finally get York Pibrary going, which will be one of Leeds Raspberry Jam’s little sisters, I’ll now have my large HDMI monitor available as a spare!

hdmipi2

In use at Leeds Raspberry Jam :

rjam071216_czgp6fgwqaatfsg

Happy Raspberry Pi tinkering!

 

Minecraft Steve shimmies with micro:bit – Part 1

I found this activity, Micromine Bitcraft  , at raspberrypi.org the other day. It uses the BBC Micro:bit to control Steve’s movement in Minecraft Pi.

microminecraftphoto

The activity uses Mu micropython which I looked at before in Micro:bit with R Pi (2) – Code to micro:bit!  It wasn’t plain sailing because it also uses GPIOZero or gpiozero (as it should be spelt when you type it in some code) in Python3 and I spent a long time trying to find this on my R Pi2 SD card.  (I explained about GPIO in Geek Gran buys a Pibrella .)

In fact you need to put python3-gpiozero into the LX Terminal.  You do this as follows:

sudo apt-get install python3-gpiozero

If it says it’s not available, you need to update and upgrade your SD card’s software.

You do this by typing in LX Terminal:

sudo apt-get update

then let that happen before doing:

sudo apt-get upgrade

If it’s a long time  (or never) since your card was updated you may need to redo the 2nd one with:

sudo apt-get  dist-upgrade

but this takes ages so only do it if you really have to. (I didn’t need to – but had the wrong package name gpiozero instead of python3-gpiozero.) It asked me something about a thing called Plymouth on the way but I just typed q to quit and it carried on. So you need to check the screen occasionally or your upgrade may never complete.

Mind you, I’ve now got the latest version of Raspian with PIXEL (Pi Improved Xwindow Environment, Lightweight) so maybe it’s going to be worth it. By the way, you need to reboot, ie shutdown and start again, before PIXEL is available.

At last I went back to LX Terminal and typed:

sudo apt-get install python3-gpiozero

and it was there!

Now to return to Micromine by putting my male-female jumper wires onto the R Pi, some alligator clips onto the BBC micro:bit and joining them both together – then I’ll report back when I’ve got it working!

 

Micro:bit with R Pi (2) – Code to micro:bit!

Now to get the code onto the micro:bit.

mu2

This turned out to be easier than I expected.  I attached the micro:bit before starting up the R Pi. (I don’t know whether this matters but I thought it was better to have everything wired up beforehand.)

I took the code, you see above, from www.raspberrypi.org  resources about Getting started with the micro:bit.  I then saved it in a new folder called Mu Python and chose ‘Flash’ from the top menu to flash the code across to micro:bit.   As expected, when I pressed button A the message scrolled across the display, etc..  What I love, about the BBC micro:bit, is how easy it is to get the code onto the micro:bit.   After using some other types of microcontroller, that have required you to hold down buttons and choose exactly the correct time to flash the code, this is just so much more straightforward!

There are lots of images you can get it to draw automatically such as HAPPY and SAD faces and CLOCK faces. A full list of them is given here: micro:bit micropython .  Don’t forget to add a sleep()*  statement though e.g. sleep(500), so that your image stays on the micro:bit long enough for you to see it!

* sleep() times are in milliseconds.

Micro:bit with R Pi (1) – two steps forward …

I’d heard of this code editor called Mu Python which is a cut-down version of Python.

mu

It sounded just what I need to code my shiny new BBC micro:bit with our Raspberry Pi 2.

I went to the Mu website and downloaded the Linux version.  Now, don’t waste your time doing this!  That’s because it is not the version of Linux Mu that you need for your particular processor (which is an ARM processor) so don’t spend precious time downloading that!

Anyway, I got the impression, after reading the Raspberry Pi forum post mentioned below, that I had already got Mu because I had just had to reload my OS and software last week.  (Read my previous post Disaster struck! – disaster averted . )

After many abortive attempts and deleting the file I’d downloaded from the web, I managed to install Mu by going into the LX Terminal. (You might need Menu > Accessories >Terminal to get there.)

and typing in:

sudo apt-get update (press return)

sudo apt-get install mu (press return)

and hey presto when I looked in ‘Programming’ there it was, Mu!

If you haven’t updated your software recently you may not have Mu there to install.  In which case, you need to go into GitHub and there are some posts that explain this in the Raspberry Pi forum here: Programming a BBC microbit …  There is a lot to read there but I found it worth the learning.

Anyway, hope this helps if your stuck like I was.

Happy Raspberry Pi ing!

 

Disaster struck! – disaster averted

This week at Code Club we managed to knock the micro SD card out of the R Pi while we were working.  When I tried the R Pi again it was completely dead except for the red ‘ON’ light!  We didn’t even get the reboot message up – in fact all we got was a blank screen.

raspi_SDcard

Raspberry Pi 2 with Micro SD card from modmypi.com

Modmypi.com

I therefore had to reformat the card and load NOOBS again.  NOOBS stands for – New Out Of the Box Software.  (NOOBS has the Raspbian Operating System and all the other software e.g. Scratch, Python, Minecraft Pi as well as the capacity to reboot all this back.  You need to reboot if you corrupt your SD card, in a less spectacular way, e.g. by turning off before a proper shutdown.)

See my earlier post from November 11, 2014 What I wish I’d known about Raspberry Pi for more on shutting down properly.

Reformatting your micro SD card is fraught with danger.

Firstly, in order to put it in your PC you probably need an adapter as shown in the photo so that you can put the card into a slot for a standard-sized SD card.

Secondly, it is really important you know which drive your card is in. Mine was in E:/.  If you don’t check this carefully you could reformat, i.e. wipe, your hard disk!

This page: NOOBS set-up gives you all the instructions to format and reload your SD card.

Hope it helps if you have the same disaster!

Happy Raspberry Pi-ing!

 

Geek Gran learns Linux jargon – SSH

The lovely new MagPi (Issue 47) for July 2016 contains an article on robot kits on page 84-85.

MagPi

This is a previous edition of The MagPi

A previous issue in January 2016 (Issue 41) reviewed another robot kit (page 82) and I was pleased to say that I could understand what they were getting at, in almost all of the text.

The new article this July was not so easy to understand. It contains the acronym SSH with respect to joining the robot to the Pi.  SSH means Secure Shell and seems to be something about sending the program code over a wifi connection to the robot. It looks like there’s a particular SSH for Linux-type operating systems (OS) such as the Raspian OS used on my Pi.

When I’ve found out more about this I’ll add to this post.

 

Geek Gran interacts with Minecraft at last!

Over the last few months I’ve been trying to use Python with Minecraft and not succeeding until today.

Interact_with_Python

It was made easier when I bought a microSD card for the Pi Zero. The software is up-to-date so that really helps.  With an SD card adapter, I could put the microSD card into our Raspberry Pi model B and I thought I was home and dry.

I am following Carrie Anne Philbin’s instructions in her book ‘Adventures in Raspberry Pi’ or you can look at her Geek Gurl Minecraft video.  I just couldn’t get it to work and then read somewhere that you can only use Python2 with Minecraft.  That was the answer!  I followed her instructions and although when I put cd api/python into LXTerminal it wasn’t happy, when I followed the rest of the instructions my message appeared on the Minecraft game window, so I’ve cracked the interaction part.

By the way, I opened Python2 and used Idle, as a text editor, rather than the editor which she uses in her book.  Also, it seems to be important to use a capital letter in ‘Minecraft’ in line 2 of the code but I don’t know why.  One useful thing I found was that if I opened my previous Python3 attempts in Python2 they worked, consequently my failures were of some use after all.  So that’s as far as I’ve got, but presumably coding other features with Minecraft should be easy now that I’ve learnt to interact with mc!