Android Question There is any way to make on-the-Fly Bluetooth sending message ?

[Adamdam]

Greetings,

There is any way to make on-the-Fly Bluetooth sending message, without pairing (that take long time and only dedicate communication between two mobiles only).
I need to enable multiple mobile devices send short message to certain one in very low time (Students-Attendance by Bluetooth).
My suggested scenario : open certain app and (and this app will open Bluetooth) then mobile app send student-ID only.
That sure will occurred in very low time, and on the class, all attendance will store in Lecturer-Mobile (local DB, without need for Internet presence or not)

Any help, please
Best regards

 

[William Lancee]

I haven't tried it but I think that you could detect all active bluetooth devices in a classroom.

https://www.b4x.com/android/forum/threads/pybridge-bleak-bluetooth-ble.165982/

 

[William Lancee]

The pybridge approach works only on B4J, but if you have a laptop you could survey the Bluetooth broadcasts in your class.
You could either register the devices' ids or ask each student to run an app broadcasting a BT message on their device.

 

[Adamdam]

I haven't tried it but I think that you could detect all active bluetooth devices in a classroom.

https://www.b4x.com/android/forum/threads/pybridge-bleak-bluetooth-ble.165982/

I tried to run this example but got this error

any solution ? please, And how can I run this example? I think we need other App run on near mobiles, correct me.

 

[teddybear]

I tried to run this example but got this error

any solution ? please, And how can I run this example? I think we need other App run on near mobiles, correct me.

You need to upgrade B4J

Depends on B4J 10.2 beta #4+

 

[William Lancee]

You could register the devices' ids at the beginning of the course. Then no app on device is needed.

So long as the student..
1) doesn't change device
2) has device BT on and device on
3) has the device with them

Otherwise, if they want to be counted, they should let you know (i.e register again with new id or 'present' manually).
You will know know of any 'missing' ids, and from your initial registration know who they are.
So you could double check if the missing students are present.

This approach, if it works, would need just one B4J app based on pybridge.

Anyway these are just ideas. I have not tried or tested this.

 

[emexes]

So long as the student..
1) doesn't change device
2) has device BT on and device on
3) has the device with them

Wouldn't those all be issues with any wireless rolltaking solution?

But if it gets you 90% of the way there, then if the system knows which students *should* be present, then it can also narrow that list down to students who should be present but appear not to be, which could save 90% of the manual rolltaking time.

 

[William Lancee]

After some research, this seems not possible and/or not practical.

1. The MAC #'s of the BT devices are not consistently available. On iOS not at all.
2. Many students come with their laptops, which may or may not have BT.
3. Privacy concerns would make some students uneasy.

I looked at alternative approaches to attendance taking.
Some are ingenious, such as face recognition, QR codes, web-based systems.
All can be circumvented by clever students.

That of course was always the case, even with manual systems. Someone can represent themselves and a buddy who is absent.
But this can be made more difficult, without adding distractions from the educational aims of the class.

For example, if the student arrives at the class room, they will see a one-time opening code for that location and time at the front of the class.
They can send a SMS text of that to a receiver which logs the sender, time, and code.

When the class is finished, another one time closing code for that location and time is displayed at the front of the class
If attendance is important to the student, they will send a SMS text of that code.

The students are registered with their phone numbers, so the source of the texts is known.
If someone wants to cheat they give their phone to their buddy to do the texting for them.

Others may have other ideas. I am interested in hearing them.