thomsoni
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Joined: Wed Jan 23, 2019 3:03 pm

Setting up a Classroom of 30 Pi's

Wed Jan 23, 2019 3:21 pm

Hi,
I'm a complete novice to this but have 30 Pi's that we want to use as a python programming lab separate from our main network. We have a wireless router and a temporary laptop with Debian x86 installed (that if successful will be replaced by a more appropriate machine) to act as a server.

Can anyone point me in the direction of a guide on how to connect everything up?

My idea is to initially store all files centrally to avoid the need for highly portable memory cards and then see where we can go from there.

Advice/ideas all welcome.

Thanks

Iain

fruitoftheloom
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Location: Delightful Dorset

Re: Setting up a Classroom of 30 Pi's

Wed Jan 23, 2019 4:28 pm

thomsoni wrote:
Wed Jan 23, 2019 3:21 pm
Hi,
I'm a complete novice to this but have 30 Pi's that we want to use as a python programming lab separate from our main network. We have a wireless router and a temporary laptop with Debian x86 installed (that if successful will be replaced by a more appropriate machine) to act as a server.

Can anyone point me in the direction of a guide on how to connect everything up?

My idea is to initially store all files centrally to avoid the need for highly portable memory cards and then see where we can go from there.

Advice/ideas all welcome.

Thanks

Iain

http://pinet.org.uk

https://www.raspberrypi.org/blog/piserver/
Rather than negativity think outside the box !
RPi 4B 4GB (SSD Boot)..
Asus ChromeBox 3 Celeron is my other computer...

incognitum
Posts: 476
Joined: Tue Oct 30, 2018 3:34 pm

Re: Setting up a Classroom of 30 Pi's

Wed Jan 23, 2019 5:44 pm

Note that the steps about enabling network boot on the client Pi's is only needed on older Pi 3 (without the +), and can be skipped if they are model 3B+

On your laptop, just go to the start menu -> "Preferences" -> "PiServer"
and follow instructions.

==

Oh, and you need a network switch and cables.
Wireless will not do.

thomsoni
Posts: 2
Joined: Wed Jan 23, 2019 3:03 pm

Re: Setting up a Classroom of 30 Pi's

Fri Jan 25, 2019 11:43 am

Thank you for the information, really helpful... just need to find switches and rewire the room again :? :cry: thought we could get away with wireless.

incognitum
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Re: Setting up a Classroom of 30 Pi's

Fri Jan 25, 2019 12:12 pm

thomsoni wrote:
Fri Jan 25, 2019 11:43 am
thought we could get away with wireless.
That's not going to work for booting.
Although technically you could have operating system files on SD card, but store user's files (home directory) on a central server over wifi.

Will always be a lot less reliable than cable though, and you then need a solution to prevent SD cards disappearing.
So not really recommended.

Gbaman
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Joined: Mon Jan 21, 2013 2:43 pm

Re: Setting up a Classroom of 30 Pi's

Fri Jan 25, 2019 11:02 pm

thomsoni wrote:
Fri Jan 25, 2019 11:43 am
Thank you for the information, really helpful... just need to find switches and rewire the room again :? :cry: thought we could get away with wireless.
Unfortunately both solutions (PiServer and PiNet) require a half decent wired network. In the case of PiNet, all the details on the hardware required (including a hardware specifics video) can be found over on the hardware page - http://pinet.org.uk/articles/installation/hardware.html
One of the ways you can save a bit of money is the Raspberry Pis themselves are really only able to make use of 10/100mbit/s networking, so network switches with at least a single gigabit port (sometimes called a stacking port), can be used with your server plugged into that port and all the Pis on the slower ports. Little more lengthy description though of that all is over on the PiNet hardware page.

Plus, I would add be cautious of jumping straight to sd-card-less booting, it had a number of issues with the Pi 3s (fixed with Pi 3B+) where a number of different brands of networking switches could cause unreliability (or simply wouldn't work).
Lead developer of PiNet, a free and opensource centralised user accounts and file storage system for Raspberry Pi classrooms used in over 200 schools across the world.
http://pinet.org.uk

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DougieLawson
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Re: Setting up a Classroom of 30 Pi's

Fri Jan 25, 2019 11:36 pm

If you're sticking with SDCard booting and ethernet only, then there's no point buying thirty 3B+ raspberries (you don't need the on-board WiFi). Save some money and buy thirty 2Bs. The later models have the newer processor like a 3B.
Note: Any requirement to use a crystal ball or mind reading will result in me ignoring your question.

Criticising any questions is banned on this forum.

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rpdom
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Re: Setting up a Classroom of 30 Pi's

Sat Jan 26, 2019 4:37 am

DougieLawson wrote:
Fri Jan 25, 2019 11:36 pm
The later models have the newer processor like a 3B.
But run slower, although that can be changed. Even then they won't have the better heat and power management that the 3B+ has.

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bensimmo
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Location: East Yorkshire

Re: Setting up a Classroom of 30 Pi's

Sat Jan 26, 2019 1:27 pm

DougieLawson wrote:
Fri Jan 25, 2019 11:36 pm
If you're sticking with SDCard booting and ethernet only, then there's no point buying thirty 3B+ raspberries (you don't need the on-board WiFi). Save some money and buy thirty 2Bs. The later models have the newer processor like a 3B.
I don't think you save (if you can find them), they are the same price at Farnell, only the 3B is a few pound cheaper.
And from a quick look, nowhere else has them in stock.


Setting up a Pi network, with PiServer makes you yern for the days of T connectors and coax for a tidy easy setup, rather than the jungle of cables with a hub based system. So much wire and cables wasted ;-).

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rpdom
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Re: Setting up a Classroom of 30 Pi's

Sat Jan 26, 2019 1:40 pm

bensimmo wrote:
Sat Jan 26, 2019 1:27 pm
Setting up a Pi network, with PiServer makes you yern for the days of T connectors and coax for a tidy easy setup, rather than the jungle of cables with a hub based system. So much wire and cables wasted ;-).
Then someone disconnects the cable from the T on one machine and the whole network dies. :shock:
(yes, I had a cow-orker move a PC from one office building to another and took the cable with them, leaving an un-terminated cable in the old office).

donod2
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Re: Setting up a Classroom of 30 Pi's

Mon Mar 18, 2019 10:31 am

Hello, I am fairly new to the Raspberry PI's as well.

I started off with the RPI when I thought I was going to use it with my amateur radio. 2 weeks later I was knee deep into a project for a school my wife and I are working with in Haiti. At the current time. I have 14 desktops up and running on wifi. There is also 1 French content server and 1 file server that wired to the router and seems to help quite a bit. I have 2 additional RPI that are not connected due to desk space. Each desktop has 2 login options, 1 for students and 1 for teachers that the admin logs in and out each class. I choose to go with a Linksys router and use Wifi. I thought about PInet but I need another computer onsite but would have to have backups that can be swapped quickly and a switch with eth cables, which all adds to the power problem. The desktops run off of microSD cards and the servers use a 120gb SSD. I have a stand alone USB writer that will do USB, SD, Micro, SSD fairly quick. I chose to go this route for ease and everything is run on solar panels and AGM batteries, so I crunch watts like pennies. I have 14 spare SD and 2 extra SSD close to the school just in case. Most if not all do not all of the students do not have any experience, so the desktop is pretty basic with the Libre office , browsers and a few other programs. I have a few people that are windows computer savvy and tacking college courses in IT to teach the class 2 days a week and on Saturday during a kids club for this school year. Before the next school year, we will install 6 more RPI and power up the other 2 on site. Our goal is to have about 24 RPI in the class with 2 for teachers to use with the students. Once everyone is acclimated, then we can look at individual logins. We plan to gradually add more content and build on the skills. If I were doing this in the US, it would be a lot different, but I am dealing with a much harsher environment and harder to get to.

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B.Goode
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Re: Setting up a Classroom of 30 Pi's

Mon Mar 18, 2019 12:06 pm

Thank you for contributing your experiences. I have made no intentional change to your text but have taken the liberty of adding some vertical white space to aid readability.
donod2 wrote:
Mon Mar 18, 2019 10:31 am

I started off with the RPI when I thought I was going to use it with my amateur radio. 2 weeks later I was knee deep into a project for a school my wife and I are working with in Haiti.

At the current time. I have 14 desktops up and running on wifi. There is also 1 French content server and 1 file server that wired to the router and seems to help quite a bit. I have 2 additional RPI that are not connected due to desk space. Each desktop has 2 login options, 1 for students and 1 for teachers that the admin logs in and out each class.

I choose to go with a Linksys router and use Wifi. I thought about PInet but I need another computer onsite but would have to have backups that can be swapped quickly and a switch with eth cables, which all adds to the power problem.

The desktops run off of microSD cards and the servers use a 120gb SSD. I have a stand alone USB writer that will do USB, SD, Micro, SSD fairly quick. I chose to go this route for ease and everything is run on solar panels and AGM batteries, so I crunch watts like pennies. I have 14 spare SD and 2 extra SSD close to the school just in case.

Most if not all do not all of the students do not have any experience, so the desktop is pretty basic with the Libre office , browsers and a few other programs. I have a few people that are windows computer savvy and tacking college courses in IT to teach the class 2 days a week and on Saturday during a kids club for this school year.

Before the next school year, we will install 6 more RPI and power up the other 2 on site. Our goal is to have about 24 RPI in the class with 2 for teachers to use with the students. Once everyone is acclimated, then we can look at individual logins. We plan to gradually add more content and build on the skills.

If I were doing this in the US, it would be a lot different, but I am dealing with a much harsher environment and harder to get to.

ejolson
Posts: 5137
Joined: Tue Mar 18, 2014 11:47 am

Re: Setting up a Classroom of 30 Pi's

Mon Mar 18, 2019 3:10 pm

donod2 wrote:
Mon Mar 18, 2019 10:31 am
I chose to go this route for ease and everything is run on solar panels and AGM batteries, so I crunch watts like pennies.
Thanks for posting your experiences. I would have thought wired networking would be more energy efficient than WiFi because there is no need to power all the WiFi radio transmitters. Did you actually measure how much electricity is consumed using either alternative?
Last edited by ejolson on Tue Mar 19, 2019 3:45 pm, edited 1 time in total.

donod2
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Re: Setting up a Classroom of 30 Pi's

Tue Mar 19, 2019 12:32 pm

This was not on my radar for the organization I am with. However, it went quickly with the little time I had to get all the materials together and shipped and make the initial install easy as possible.

I did not measure with and without Wifi. With wifi enabled, the meter on the inverter shows 276 watts @ 3.2 amps AC running 14 desktops using 14 older Dell 19" monitors at 50% or less brightness & contrast (which was a huge power savings). The RPI are in C4-Labs 6 port Bramble box with 3x 50mm fans which is really needed, and an Anker 6 port USB power hub.

When I installed the system in January, we had 8 to maybe 10 hours of electric over the course of 10 days, so we are 100% solar and checking both options makes sense when crunching watts and growing the class.

walash
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Joined: Mon Jun 03, 2019 6:13 pm

Re: Setting up a Classroom of 30 Pi's

Mon Jun 03, 2019 6:26 pm

hello,

could you provide more details about the solar setup to power this lab? i'm interested in a such a project using only RPIs B+s and Pinet or PiServer for a lab of 20 students and 1 teacher. If you have a source for the solar hardware please share as well.
Thanks

donod2
Posts: 6
Joined: Mon Mar 18, 2019 9:58 am

Re: Setting up a Classroom of 30 Pi's

Mon Aug 26, 2019 8:23 am

The class is running on Renogy equipment 4x 100 watt panels, a 40amp MPPT charge controller and a 1000 watt pure sine wave inverter.

I was able to get a very good deal on the batteries and shipping, so I ended up with 4x 12v 240ah AGM. I have more battery than what I need, but the plan is to move 2 of them to another school in the near future. This at least keeps them active.

I have a 3B+ server with a 120GB SSD running RACHEL for content modules in French and English. I have thought about Pinet or Piserver, but that creates a single point of failure. The 3B+'s have their own microsd and I have 10 spares close to the school. If a PC goes down, I only loose 1 and not the whole class. It will take a matter of minutes to restore the downed PC. Eventually, once the folks running the class learn more and get comfortable, we could change the setup.

Since I can only get to Haiti a couple times a year and work remotely the rest of the time to help the teachers, we are taking it slow. There is no need to rush the learning process as most have never really worked with a computer, but a cheap smartphone at best. So far the feedback is positive and the users are embracing the class. They are excited to have new and better tools.

https://www.shininghopemissions.com/computer-class
The top pictures are the newest from Aug 2019. The bottom are from Jan 2019. The welders equipment broke down shortly after the panel cage, so he was not able to get the desks made from angle or tube steel, so we used what we had, 2x 6ft by 30 inch tables. There were other issues beyond me this time around and almost everything was completed. The batteries are also being enclosed in a cage before school starts.

kmrp
Posts: 2
Joined: Fri Dec 27, 2019 12:09 pm

Re: Setting up a Classroom of 30 Pi's

Tue Dec 31, 2019 3:50 am

How has this been going? Expecting to have a similar setup in rural Kenya. One concern is reliability. What is the expected lifetime for the setup? Is there a maintenance and possibly replacment plan for the computer classroom? Is your classroom mostly offline or does each of the terminals have good internet access, so that content does not need to be served locally? If it is served locally, does this work well? Have you developed much local teaching material?

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