Inconsistent connection over WiFi (school network)

[Kyle]

Hello everyone,

I have been using Kindle Fire HD 8s with my classes to teach the basics of App creation. My students build on their Chromebooks and connect to the Kindles via school WiFi. 

The issue I am having is with the consistency of the connection; sometimes the students will be able to connect to their apps and sometimes, after scanning the QR code and trying to connect via the code, the companion app will hang and not do anything. 

All the Kindles are updated with the latest AI Companion and it is not a specific one that will have the issue. Using all 11 of my Kindles (and sometimes my Galaxy S7 Active), generally I will have 1 - 3 devices (not necessarily the same ones) that will not connect. The apps we are creating usually have the same components and code, so I don't think it's an issue there. I have tried restarting the devices and also resetting the companion connection; sometimes it will work, but more often than not it won't.

Has anyone else in the educational setting experienced this problem?

Thanks,

~Kyle

[TimAI2]

Could be a local network issue? Are all the chromebooks and kindles on the same subnet e.g. 192.168.100.20 and 192.168.200.21 are different subnets.

IT departments often set wifi up on a different subnet and don't always do the crossover so everything can connect to everything

[SteveJG]

Hi Kyle

A first guess is your class may be exceeding the WIFI capability of your school network. When "trying to connect via the code, the companion app will hang and not do anything" could be either than WIFI being overloaded  or an issue with an individual project.

A second guess,despite your comment "so I don't think it's an issue there"  is the issue may be coding issues.  It depends on what "re creating usually have the same components and code"  and the word 'usually'.     Small differences in code and possibly audio or video files in individual projects , for instance, stored in Media can cause serious issues.

Something telling is that no particular phone appears to be 'glitched'.   Has your school IT made changes to the network recently  or are the student's projects getting larger, more sophisticated, etc. ?  

If the second guess is right, you might be able to use App Inventor's alternate log in

1. http://ai2.appinventor.mit.edu
   
2. http://code.appinventor.mit.edu

Instead of #1, try having students with fussy Apps try  #2.  #2 does not have the time out restrictions of #1  but is not a substitute for possible less than optimum coding.

So if you can, try the alternative url if a Project fails .  You can try to ensure ALL students are not downloading with QR code at more or less the same time if the network capacity is the issue.

Regards,

Steve

[Kyle]

Hey guys,

Thanks for the quick responses. I will forward this on to our IT person and see if he can change something up on his end. I'll also have the students space out when they try connecting to their apps. Being relatively tech savvy (but not with administration privileges) is there something I can do to have all the Kindles and Chromebooks on the same subnet? It's never a particular Chromebook or Kindle, so maybe that is the issue.

Regarding the simple apps, I mean reallllly simple. As in apps that have 2 button components that change different properties of a label component and that's all. Still, I'll give that separate URL a try.

Thanks again,

~Kyle

[Kyle]

Steve:

I am talking with my IT guy and he asked how much data the projects need to send... is there anyway to find out how much is sent per project?

Thanks again,

~Kyle

[SteveJG]

@ Kyle ... it certainly varies.  I just asked MIT to respond with how much data is sent from the Kindels to the server and how much data is returned.  That might help.

--Steve

[Kyle]

Alright!

Thanks again guys,

~Kyle

[Abraham Getzler]

A Chromebook-resident emulator like Arc Welder

might help, as a fall-back.

It would be far off the beaten path, though.

ABG

[Evan Patton]

Hi Kyle,

There are three steps to establishing the connection between the web session and the Android device. They have different requirements for bandwidth.

1. IP address exchange via the QR code. This is on the order of tens of bytes and goes through the server at rendezvous.appinventor.mit.edu. After the information has been exchanged, the QR code will disappear.

2. Browser retrieves assets from the web. This will be O(n) in the size of the assets. Exporting the project and looking at the size of the AIA will give a rough approximation. (Progress bar < 50%)

3. Begin peer-to-peer communication (sending assets, code) directly between browser and device. (Progress bar > 50%)

I assume that you have gotten past step 1 and are stuck somewhere between steps 2 or 3. One way to check whether asset transfer between the devices is a problem is to connect with an empty project open and see if you have trouble without the assets.

Regards,

Evan

[Kyle]

Thanks for the in depth answer!

A new work around I have noticed is that if I close out of the specific app I am building and reopen it, it will then allow me to connect a good portion of the time.

[Evan Patton]

Hi Kyle,

When you say "if I close out of the specific app I am building and reopen it," do you mean that you are closing the app on the device or in the web browser? If the latter, try also using the "Reset Connection" menu item in the Connect menu to see if that helps.

Regards,

Evan

[Kyle]

Hello again,

I have the students close out of the project on their Chromebooks and reopen it after trying the reset connection option. I have had slightly more success with closing and reopening the project on the Chromebooks.

I also forwarded on your last response to our school IT person and they did confirm that we are pretty taxed on our bandwidth during the day and are looking into increasing it. 

Thank you again for all your help!

~Kyle