Prepare for the Raspberry Pi workshop
(Short URL: http://tiny.cc/pistart)
A few things to do in advance
The Raspberry Pi is a small computer. You can learn a bunch of stuff that's useful for Raspberry Pi on your existing computer!
- Have a look at GeoGebra, Scratch, and OpenOffice.
- Read the text below on Raspberry Pi without a monitor, and see what you can do to prepare
To find out specifically about Raspberry PI:
- A good place to start is the Raspberry Pi resources page http://www.raspberrypi.org/resources/.
- Another good resource is the "learn" section of the Adafruit shop https://learn.adafruit.com/category/raspberry-pi.
- Also: http://www.elinux.org/RPi_Hub and http://www.raspberrypi.org/help/faqs/.
- If you're a beginner with Linux/Unix, you should also look at something like this: http://www.ee.surrey.ac.uk/Teaching/Unix
Raspberry Pi without a monitor ("headless")
If you're coming to a workshop, please bring your laptop! Here's why.
The Raspberry Pi is a little, but fully-fledged computer, that can be used with a keyboard/mouse and a screen (computer monitor, or TV, DVI, VGA, HDMI, or composite). However, for many workshops, it's not possible to bring sufficient screens and keyboards/mice - you'll appreciate that the size and weight of monitors/keyboard are many times that of the Raspberry Pi!
However, at workshops, participants often come with their laptops, and fortunately we can use these to connect to Raspberry Pi, which means we don't need monitors/keyboards. In other words, the laptop can act as the screen and keyboard/mouse for the Raspberry Pi.
You can do this in two ways:
- Using "ethernet" (using the wired ethernet ports on the laptop, connected to the ethernet port on the Raspberry Pi)
- Using a "serial connection" (using a USB port on the laptop, to connect to some GPIOs on the Raspberry Pi)
We call this way of connecting to another computer "headless" (as opposed to using a monitor, the "head" in this analogy).
Serial connection
The serial connection is easy to set up, but allows text-based access only, and requires a special cable (which is cheap, but takes time to order). It just requires the installation of a driver, and downloading putty (on the laptop). You use You can then easily connect to the Raspberry Pi. However, this is text-based only. This is sufficient e.g. to explore sensors and some programming, but it doesn't allow you to use any graphical applications, or to see the "Desktop".
Note that the serial connector cable also allows you to power the Raspberry Pi from your USB port.
- However, you should only over use one source of power: Don't connect both serial power and the micro-usb power
- See here for how the serial cable needs to be connected when you power the Raspberry Pi from micro-usb power (and not from the serial/UART)
- When you are not using micro-usb power (e.g. from a mains socket), then also connect the red wire shown here, and this will power the Raspberry Pi via the serial/UART.
- Note that via the serial/UART cable, you may only be getting just enough power to the Raspberry Pi. This is because the USB standard only mandates 500mA. Many devices can supply more than 500mA via their USB port, but this may or may not be the case. Overall 500mA is not enough, particularly if you connect further peripherals to the Raspberry Pi (e.g. USB devices in the Raspberry Pi USB ports, that draw power from the Raspberry Pi).
- Even if you use the serial/UART connection to power the Raspberry Pi, you can still connect the ethernet cable (see next section).
By "micro-usb power" we mean power supplied to the Raspberry Pi's micro USB socket, e.g. from a micro-usb power supply (mains powered) or a micro-usb cable. These difference scenarios are showns here: RaspberryPi/UART.
Ethernet (ssh / VNC)
Making an ethernet connection just requires an ethernet cable (which is easily available), and it allows both both text-based and graphical user interfaces. However, in the absence of a "switch" (which we cannot bring to the workshop in sufficient numbers), it requires setting up “Internet Connection Sharing” ("ICS").
If you can, please explore “Internet Connection Sharing” on your laptop before the workshop, and enable it. You can then just connect to the Raspberry Pi using an ethernet cable (which we will provide).
Also, install a serial terminal app and a VNC client.
- On Windows, install putty, as well as the (to follow) VNC client.
- On Mac OS X, install zterm, and ChickenOfTheVNC. (Note that you can use e.g. Screen within the OS X Terminal app also, but I've found zterm better.
- If you have a linux laptop, install (to follow)
bushcraft
We have developed some tools to give support when using Raspberry Pi / linux in more challenging environments, see https://github.com/bjohas/bushcraft.
