Low number of Wi-Fi concurrent connected users

dgachet

do we change the raspberry's wifi driver to compensate for the low number of connected users ?

Nicolas

dgachet I don't know if this is possible.

But why do you think it would change anything? Do you have any evidence that the driver limits the number of clients?

Ratna

dgachet Did you see this discussion https://www.raspberrypi.org/forums/viewtopic.php?f=36&sid=c9e7a3b665b9ed99ab28bf2fd6622c27&t=76604 linked to the StackExchange link earlier? It is very detailed but outdated since we are interested only in the built-in wi-fi chip of Pi 3B+. It would be great, if you could tackle the issue and raise the number of wi-fi connected devices of the MoodleBox!

Nicolas

For the sake of completeness: following several discussions of the Raspberry Pi forum and on the advice of the principal software engineer at Raspberry Pi, an issue was reported to the RPi Foundation for investigation, since such a limitation seems to be a bug.

bicyclemark

Im just a teacher working in low tech and often hostile environments, I don't have a technical explanation but I can tell you after numerous experiences my maximum participants taking a quiz using MoodleBox RP3B+ is 8. Once 9 or more connect and get active, someone inevitably loses connection. Even with full power and sitting about 1 meter from the box. Im actually using strategies in class to keep everyone from working on the quiz at the same time so that there are no disconnects.

Nicolas

bicyclemark Did you check if your red LED blinks? (see https://discuss.moodlebox.net/d/36-low-number-of-concurrent-connected-users/19)

cbixel

I had the same issue today with MoodleBox on a RPI 3 B+.
This was a new install of the latest supported Moodlebox. I noticed that about 14 students could connect. No more could connect. From what I have read, this seems to be an issue with the wireless capabilities of the RPI 3 B+, and it is suspected that it is an issue that might be solve with coding.

Here is my question, in the meantime, would it be possible for me to get around the issue by simply plugging a wifi dongle into the RPI?

I even have a spare router in my basement that I could bring into the classroom and hook up somehow.

I must admit, I am pretty new at this.

Finally, would it work if I were to just take the microSD card out of the RPI 3 B+, plug it into a RPI 3 B, and try that? I have heard that the RPI 3B might be able to handle 25 students without issues.

Nicolas

Your best bet is first to check your power supply.

cbixel Here is my question, in the meantime, would it be possible for me to get around the issue by simply plugging a wifi dongle into the RPI?

I don't know. But the issue seems not to be hardware related. And it'll certainly depend on the dongle model. Anyway if you try please report your results here!

cbixel Finally, would it work if I were to just take the microSD card out of the RPI 3 B+, plug it into a RPI 3 B, and try that?

Yes it'll work.

I have heard that the RPI 3B might be able to handle 25 students without issues.

Just like the RPi 3B+, if you've an adequate power supply :-)

Ratna

cbixel The red power LED need to be 100% steady, no blinking, no changs in brightness at any time. The newer MoodleBox images shows a "soft" indicator for the Moodle administrator if the supply voltage drops. I found it to be too cautious, much on the safe side, though.

ThomasG

Hello,
first, thanks für the good work. I love the idea of moodlebox.
But I've the same problem. The maximum of connection was 10 users.
I'd tried it several months ago with a raspberry pi 3b+ and this week with the new raspberry pi 4. I worked with different power supplies. The red light was always stable.
Two questions
Is there any new idea for fixing the problem?
where can i find the "soft" indicator, if the supply voltage drops.

Ratna

ThomasG That is disappointing! I am sure, I had more connected (13?) in an earlier version, on RPi 3B. Others have also reported up to 20+. Can you ask your users to connect one-by-one after, waiting till their predecessor appears on the MoodleBox Dashboard (Site administration > Server > MoodleBox > MoodleBox dashboard)?

There is a soft indicator for low voltage - a red button. It appears only if the supply voltage drops.

@Nicolas Isn't it an idea to display the button always and make it change in colour?

Nicolas

ThomasG where can i find the "soft" indicator, if the supply voltage drops.

The warning is displayed to administrators of the Moodle, on every Moodle page. This was added to MoodleBox version 2.7.0, but you can simply upgrade the MoodleBox plugin to the last version and get the feature.

Nicolas

FYI: I got 21 WiFi clients during a presentation in July 2019, so you should get approximately the same (see screenshot).

Ratna Isn't it an idea to display the button always and make it change in colour?

Which button? What do you mean exactly?

Ratna

Nicolas Sorry for the misleading question! What i meant was, currently the low voltage warning appears only if the voltage is low - no message if OK. How about displaying a message always: indicating either the voltage is good or is not good?

Ratna

Hi Nicolas, now I see the problem with my suggestion. The low voltage warning appears on top of every page. A voltage OK message on top of every page would be annoying! I am taking back the suggestion.

Nicolas

Ratna Yes, I think too this would be annoying.

Entitymarck20

so to adjust the amount of people we have to go to MoodleBox Dashboard (Site administration > Server > MoodleBox > MoodleBox dashboard)?

Ratna

Entitymarck20 Do you mean, you want to limit the number of wireless devices that can be connected to the MoodleBox hotspot? No, there is no such setting.

Entitymarck20

Ratna I do not mean to limit, but to expand the use of connected PC at the same time, since I think for the other year to implement it in the school that I am, but I only connect 10 pc

Nicolas

Entitymarck20 If you can connect only 10 devices, check the red LED and change your power supply!

Entitymarck20

Nicolas When it comes to the LED, it is the one that produces the raspberry pi and the source is going to change these days, since I am using the one on my phone, what voltage do you recommend?

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