When scanning for devices nothing is found

Patryk_F · August 15, 2023, 1:33pm

It has already been explained in this topic. Next time read the thread before asking a question. I will repeat:
No scanning and connection permissions.

(Canned Response ABG - Bluetooth non-BLE SCAN Permission Blocks)

These blocks can be dragged into your Blocks Editor to request permission(s) for Bluetooth non-BLE scanning and connecting. All three parts are needed.

You also will need to pull in TinyDB into your project.

Thanks to @Anke for the original code.
My changes include

use of the Screen1 permission blocks to avoid the possibility of a typo
using a TinyDB tag particular to BT permissions and only for BT permissions.

Special note for Xiaomi devices:

YellowLizard · August 15, 2023, 6:23pm

As a 'power user' you obviously understand the above blocks, unfortunately they are double dutch to me.

What are you supposed to with them?

I have added the 3 blocks to the beginning of my blocks and added the Tiny DB and a 'list view' box, but it doesn't seem to do anything. It does find and display the BT module but doesn't select anything.
The original problem (with which I started this thread) has now just gone away, as I said above, but I have no idea why!
I have now completed my project (without the 3 above blocks) and it all works perfectly BUT only if I connect the android companion app to the PC. I have downloaded and installed the .apk file on the android device, the app displays the right info and looks OK until (yes, you've guessed it!) the 'find device' button is pressed when all I get is a blank screen again.

So is this connected with my original problem and if so will the 3 extra blocks solve the problem, even though it works perfectly until it becomes an apk?
If the extra blocks will solve the latest problem how do I use them and how do I incorporate them into my code?

This what I've got so far:-

blocks(22)

Any help greatly appreciated,
Thanks

Patryk_F · August 15, 2023, 6:29pm

I still don't see in your blocks the most important "AskForPermission" blocks that I showed above. Modify your blocks as suggested by adding scan and connection permission requests.

Of course, instead of ListView which is in the example, use ListPicker, because that's what you use in your app.

YellowLizard · August 15, 2023, 6:44pm

Thanks for your reply.

What I listed above is how I now have it (almost) working. I have tried it with the other 3 blocks (the ones with permissions) and I did change list view to list picker. I put the 3 blocks above the ones listed above, but it all made no difference.

I have downloaded and installed 2 apk versions, one with the extra 3 blocks and one as above but they both behave the same.

Thanks again for your help.

YellowLizard · August 18, 2023, 2:03pm

FINALLY! I have been going insane over this for the last couple of months, today I finally got it all working.

So thanks again to everybody who tried to help but it appears there was an 'error' in one of the extra permission blocks suggested by ABG above. (I put 'error' in inverted commas because there may not have been an error and there might have been something else wrong, no idea, but what I added solved the problem).

So I changed the second block to this and it all sprang into life.

As you can see, I added a second 'call' box which solved the problem. Maybe someone who understands it all far better than I do can dissect my solution and decide if it was good/bad/needed or whatever!
All I know is that it worked, so thanks again for all the help and I hope someone else may find my solution helpful.

Patryk_F · August 18, 2023, 3:49pm

Yes, there is a bug in blocks from ABG.

There are correct blocks in this post.

Just drag them to the project and change ListView to ListPicker, add TinyDb and that's it...

ABG · August 18, 2023, 4:10pm

Show me, so I can fix it?

Patryk_F · August 18, 2023, 4:45pm

This is the original block:

When you ask for the BluetoothScan permission in the Initialize event, only TinyDb is set to true in the above block, and the BluetoothConnect permission is not asked.

You need to change the order like this:

Now when you grant BluetoothScan permission, you will be asked for BluetoothConnect permission.

You can also change the Initialize block by replacing the BluetoothScan block with BluetoothConnect.
But in my opinion, the order of Scan first, then Connect is more logical.

ABG · August 18, 2023, 5:18pm

(Canned Response ABG - Bluetooth non-BLE SCAN Permission Blocks)

These blocks can be dragged into your Blocks Editor to request permission(s) for Bluetooth non-BLE scanning and connecting. All three parts are needed.

You also will need to pull in TinyDB into your project.

Thanks to @Anke for the original code.
My changes include

use of the Screen1 permission blocks to avoid the possibility of a typo
using a TinyDB tag particular to BT permissions and only for BT permissions.

(Thanks to @Patryk for correction to grant order)
Special note for Xiaomi devices:

Boris_Weisser · August 24, 2023, 4:22pm

Even after entering the suggested blocks, the application does not offer me a list of bluetooth devices. It sends an error:

This is my code:

Taifun · August 24, 2023, 5:11pm

it looks like the definition of your csv table is incorrect...
here you can find the correct csv string

Taifun

ABG · August 24, 2023, 5:40pm

Here's an .aia
apiLevel.aia (3.4 KB)

Boris_Weisser · August 24, 2023, 9:01pm

I tried to enter the suggested sequence ( 1.0,1\n1.1,2\n1.5,3\n1.6,4\n2.0,5\n2.0.1,6\n2.1,7\n2.2,8\n2.2.1, 8\n2.2.2,8\n2.2.3,8\n2.3,9\n2.3.1,9\n2.3.2,9\n2.3…) in the code, but there were no results.
It shows the same error.
I am a beginner with MIT APP and I do not fully understand all the advice and recommendations.
Thanks a lot for trying to help though.

Boris_Weisser · August 24, 2023, 9:07pm

I don't know how to open the offered .aia, but in fact I don't know how and where to use it.
Thanks for trying to help.

Taifun · August 24, 2023, 9:11pm

The correct string is

1.0,1\n1.1,2\n1.5,3\n1.6,4\n2.0,5\n2.0.1,6\n2.1,7\n2.2,8\n2.2.1,8\n2.2.2,8\n2.2.3,8\n2.3,9\n2.3.1,9\n2.3.2,9\n2.3.3,10\n2.3.4,10\n2.3.5,10\n2.3.6,10\n2.3.7,10\n3.0,11\n3.1,12\n3.2,13\n3.2.1,13\n3.2.2,13\n3.2.3,13\n3.2.4,13\n3.2.5,13\n3.2.6,13\n4.0,14\n4.0.1,14\n4.0.2,14\n4.0.3,15\n4.0.4,15\n4.1,16\n4.1.1,16\n4.1.2,16\n4.2,17\n4.2.1,17\n4.2.2,17\n4.3,18\n4.3.1,18\n4.4,19\n4.4.1,19\n4.4.2,19\n4.4.3,19\n4.4.4,19\n4.4W,20\n4.4W.1,20\n4.4W.2,20\n5.0,21\n5.0.1,21\n5.0.2,21\n5.1,22\n5.1.1,22\n6.0,23\n6.0.1,23\n7.0,24\n7.1,25\n7.1.1,25\n7.1.2,25\n8.0,26\n8.1,27\n9,28\n10,29\n11,30\n12,31\n12.1,32\n13,33\n14,34

Taifun

Boris_Weisser · August 24, 2023, 9:37pm

Unfortunately, even that sequence does not accept me and reports an error (Invalid list of pairs). I must have made a mistake in something else.
Thanks for the help, I'll try again tomorrow maybe with some corrections. But it's still a bit overcomplicated, so many lines of code just to connect to bluetooth.

Patryk_F · August 24, 2023, 10:59pm

Show the error screenshot for the list that Taifun showed.

ABG · August 24, 2023, 11:18pm

Project->Import
then use the backpack to transfer parts from project to project.

Boris_Weisser · September 1, 2023, 8:00pm

Finally it worked for me too.
Thank you guys very much for your time and effort. ABG I was able to open .aia and later use backpack. Many thanks also to Taifun, Patryk_F and YellowLizard.
I followed your instructions and used your blocks but it only worked when I corrected the second block as shown by YellowLizard.
This is my code that works and the mobile app prints the bluetooth list.

Finally, just one more question, guys. Which is why a few months ago everything was working on the same mobile phone and the bluetooth list was printed even with a much simpler code (the one you can find on You Tube tutorials), but now only with this very complicated procedure.

Taifun · September 1, 2023, 8:49pm

Because of the SDK31 update from last year... Google restricts the Android system from year to year and introduces new rules... the reason usually is to provide better security... thank you Google for protecting us... /sarcasm

Taifun