A Raspberry-Pi image set-up by us with all kinds of useful free software for laboratory and analysis application.
left: the credit-card sized Raspberry Pi (RPi) and its “harddrive” – a standart issue SD-card. Right: The RPi with the TReND install running and connected to a standard LCD screen with keyboard, bmouse and WiFi dongle. Just plug it and it works!
What is a Raspberry Pi?
It is a very small computer designed to run Linux. It comes with a processor, 256 or 512 MB working memory and several connectivity options. The “harddrive” is an SD-card.
What can it do?
It is basically a fully functional computer that runs as fast as a descent smartphone. So, it’s fine for things like word processing, spreadsheets, basic programming, presenting powerpoints and browsing the internet. It won’t suffice to play high-end computer games or use very memory consuming rendering softwares. But then again, it does run the popular 3D shooter Quake-III Arena (open Arena) rather well, so don’t underestimate it!
Why should I get one?
The prime reason of course is cost. If all you ever do on a computer is browse the web or mess around with text-editing software and excel sheets, this thing will be just fine. Similarly, to teach about basic computing or programming skills, e.g. in schools or universities, these devices are easily sufficient for most applications. The next reason is size – they are tiny so if you don’t have a lot of space, this may be a solution. They fit in your pocket! Another attractive feature is the SD-card “harddrive”. This means that by swapping SD-cards, you can essentially swap computers! One SD card may have all your work softwares etc installed, while another can have your private things. Or you could have one SD-card just running a home entertainment software, such as XBMC. Just swap the card, and repurpose the computer! In the US, XMBC is the #1 application of RPis in private households. Note, though, RPis can be used as dedicated mini computers for all kinds of things: for example, TomToms are popular. Just google “RPi applications” or browse youtube. The list is endless, and ever expanding! One thing, for example, could be in libraries in places with limited resources – reading ebooks on a screen connected to the RPi – the ebboks can even be archived on USB sticks and connected on demand. Or accessible through a hardwired ethernet system – this doesn’t even need internet, just a central server controlling the whole thing.
What does it cost?
– RPi itself (just the PCB board, i.e. the green thing with all the electronics on it): 25-40 USD.
– Plastic casing (optional) – ~10-15 USD. Note, that this can be 3D printed as well.
– cables and adapters: a monitor is connected via standard HDMI (looks a bit like USB but wider), or, altenatively, composite (the round yellow one). Check your Screen /TV for these options. Note that these are different from VGA (the 15 pin blue one) or DVI (the 24 + 1 pin ones). Luckily there are adapters for everything – usually around 10-15 USD.
– if you want WiFi you will need a WiFi USB dongle – usually around 10-20 USD. Note that the RPi has an ethernet cable connector inbuilt, so you may not need WiFi.
– USB hub – the RPi has 2 USB ports. Depending on how many USB devices you want to connect, you may need a hub (10-20 USD)
(for now here is just a guide how to do it though the main RPi websites…). Note, very useful is also their quick start guide
Also, a much better guide than ours here is this one
1) Get your SD card ready. You will need some form of SD card reader. Format your card if need be e.g. using this.
Note1: SD cards of 8GB or bigger are nice to use as they are not immediately clogged by the OS alone. Indeed the “NOOBS” install using Raspbian (see below) takes ~1.5 + 2 = 3.5 GB alone – so on a 4 GB drive thats not much fun…. Of course one can not install NOOBS but straight Raspbian which isnt too hard – this saves the 1.5 NOOBS files so on a 4GB drive you have 2GB left to play with…
Note2: SD cards have different speeds – the SD card speed will reflect on the peed of your system – so its nice to pick a descent one
2) pick an OS (Operating system). Most newcomers will go with “NOOBS” which makes installing things as easy as copying some files. Plus it gives the option to install more than one OS on the card so you can later flip back and forth between them to see which you like best. see here. Install the OS as detailed on that website (yes, it is literally download + copy onto SD card – that easy!). Then boot up the RPi with the SD card mounted and choose your OS in the 1st screen it shows. We recommend Raspbian, it is the best all-rounder and has most community support.
3) Configure initial things. The RPi will boot into a BIOS like menu where it gives you a bunch of useful options. e..g. you can enable the RPi camera if you have one. or chnage the password, language, things like that. You can also overclock here if that’s your thing. Press Finish to reboot – now it should boot all the way to a command prompt. Type “Startx” and it will launch your new Desktop! NOTE – the default login / password for NOOBS is pi / raspberry (and on TReNDBerry Pi is pi / TReND)
4) get your internet working! On your desktop there is a WiFi Config icon – the procedure should be self explanatory (this of course only works if you have a WiFi dongle attached). Alternatively, with Ethernet the RPi should just connect (hopefully). If not, google a bit (yes, not on the Pi, on a computer that is connected…)
5) arrange preinstalled stuff. E.g. there is are two browers installed (“NetSurf” and “Midori”). NetSurf is hidden under start/internet/NetSurf… exlore whats already there. To add Links to the desktop just right-click them
6) install stuff (using Linux Terminal)
e.g. Libreoffice (248 MB):
sudo apt-get install libreoffice
This will install the Office suite “LibreOffice” from an online repository – which will probably take about 20 mins. Once finished (command prompt in terminal available again) the software can be found under start/Office/… – right click on parts to put links to desktop
e.g.: R-project (Statisical analysis software, 74 MB):
sudo apt-get install r-base-core
This will pop up in start/graphics/R (weirdly enough)
e.g.: Arduino software (to control and programm Arduino boards, ~80 MB):
sudo apt-get install arduino
There is lots of stuff on Ubuntu (= the online place where all the install files are) – to search, type:
sudo apt-cache search SEARCHTERM – then install as above (sudo apt-get install NAME)
to remove install again use
sudo apt-get remove NAME
sudo apt-get remove NAME* (note the asterisk)
other key Linux commands:
sudo apt-get update (updates all installs from ubuntu)
sudo apt-get upgrade (as above, but upgrades)
some ancient DOS commands in Linux:
dir –> ls (both work, actually)
del –> rm (=delete)
cd.. –> cd.. (=move up/down directories)
df (disc free, ie how much space is left? – very useful)
mkdir NAME (makes directory)
some camera commands (if you have the RPi camera)
raspivid / raspistill – video and picture, respectively
to see options, run: raspivid | less
e.g. to capture a 10 s video in demo mode, type:
raspivid -t 10000 -d