I am writing a blueprint for schools wishing to set up a Raspberry Pi lab in a secondary school.
My criteria for success were:
1. Must be dual boot PC/Pi for classroom flexibility
2. Must be networked to run PiNet
3. No extra data to be installed
4. No extra power to be installed
5. Permanent setup. No cables to ever need to be unplugged
6. Shared keyboard, mouse, monitor
7. Switch between PC/Pi with click of a button
8. SD card and Pibrella nust be secure and unable to be removed
9. Power switch for Pi
10. Use existing monitors (with just one VGA and no HDMI/DVI)
- Use existing USB keyboard, mouse, monitor (any monitor will do. Only needs single VGA), ethernet cable Cost = £0.00
- 1 x KVM switch Cost = £4.82 each Click here for details
- 2 x VGA cables (plus the one you probably already have on your PC) Cost = £1.97 each (Total £3.94) Click here for details
- 1 x USB Lead A to B Cost = £1.53 each Click here for details
- 1 x HDMI to VGA adaptor Cost = £3.14 Click here for details
- 1 x USB to micro USB to provide power to the Pi Cost =£5.45 Click here for details
- 1 x pair of RJ45 network splitters Cost = £7.99 Click here for details
- 1 x Raspberry Pi2 with SD card £33.94 Click here for details
- 1 x Pibrella Cost £9.79 Click here for details
- Velcro studs to secure KVM and Pi to top of PC Click here for details
- 3D Printed case with secure SD and Pibrella (GCode for Ultimaker Printer on request from @robjones_cowley)
Total cost = £70.60 (£56.48 ex VAT)
- Step 1 : Add Pibrella to GPIO on Pi2. Insert micro SD card. Secure into case and screw together.
- Step 2 : Power up the Pi via the Pibrella using USB to micro USB. Micro USB goes into the Pibrella and USB goes into the PC
- Step 3 : Add HDMI to VGA converter from the Pi. Connect one of the VGA cables to the converter
- Step 4 : Connect USB keyboard and mouse to the KVM switch
- Step 5 : Connect the VGA from the Pi into PC1 on the KVM switch
- Step 6 : Connect the VGA from the PC into PC2 on the KVM switch
- Step 7 : Connect the USB Lead A to B to the PC and the KVM switch (to provide power to the KVM switch)
- Step 8 : Connect ethernet from the Pi and ethernet from the PC into the RJ45 network splitter. This goes into the wall data point.
- This doubles your number of data points, allowing each data point to simultaneously the PC and the Pi without the need to swap ethernet cables.
- Step 9 : Connect another splitter into your network CAB. the single RJ45 end goes into the patch panel linked to the wall data point. The two RJ4 outlets from the splitter to then be patched into separate ports on a switch
- Step 10 : Setting up PiNet : Having networked Pis adds much more functionality over standalone Raspberry Pis including:
- Adding new software. If you want to add a new piece of software to every Raspberry Pi in the classroom, update master image on the server and reboot all Raspberry Pis
- Allow students to have their own bespoke login and save files centrally rather than on an SD card
- Students can log into any Raspberry Pi in the classroom
- SD cards will be generic and boot the Pis to the server. You can have one class set of SD cards (rather than individual student SD cards). SD can also be smaller (only need 30Mb boot files rather than 3Gb for standalone Pis) because the software is held on the server
- Backup utility included to automatically backup all students work regularly
You will need on old PC or you can set it up on an existing or virtualised server. This is easy to do (instructions for setting up the PiNet server can be found at http://pinet.org.uk). The SD card will need easing and the files generated from the PiNet folder on your PiNetDev server will need adding
This doubles your number of data points, allowing each data point to simultaneously the PC and the Pi without swapping ethernet cables.
The next issue is securing the Pis themselves. I could collect the Pis in at the beginning and end of the lesson but this is then defeating the objective of having a Pi Lab set up. There are pros and cons of vesa mounting the Pis to prevent them from being stolen/moved. The vesa mounts will secure the Pis to the back of a monitor, but in ‘hiding’ the Pis some of the excitement of using a Pi is lost; also the GPIO is less accessible. Also, some monitors have stands attached to the vesa mounts.
A good compromise is to use velcro pads. These are cheap and pads could be attached to monitor/bench/wall so that the Pi could be moved around.