micro:bit V2 cannot be flashed from Lenovo tablet - GATT WRITE NOT PERMIT

[PSLLSP]

micro:bit V2 cannot be flashed from Lenovo tablet M10; error is GATT WRITE NOT PERMIT

micro:bit V2.21
Tablet Lenovo TAB M10 (3rd gen) WiFi
Bluetooth 5.0
Android 12
micro:bit application for Android V3.0.10

This tablet was used to program micro:bit V1.5 and it worked. But we failed to flash micro:bit V2.21...

[martinwork]

All Bluetooth support in micro:bit is provided by the last program flashed, so this could be related to the program that was in V2 when you tried to pair and/or flash. To rule that out, and get a fresh start:

• Use the Bluetooth section in the tablet's Settings app to remove any existing pairings named micro:bit or DfuTarg
• Use a computer to send a hex file to the micro:bit via USB by dragging it to the MICROBIT drive.

Use the "meet the micro:bit" program hex file, or a hex file saved from a new MakeCode project (display something so you know the USB transfer has completed).
https://microbit.org/get-started/user-guide/meet-the-microbit-program/

It might help to try to reset the tablet's Bluetooth as described in #79.

[PSLLSP]

That was new micro:bit board, it was loaded with "meet-the-microbit-program". I do not like how annoying sounds it produces on V2...

We tried to use Lenovo M10 tablet first to program and flash simple example and we failed again and again.

Then I tried 10" Fire tablet from Amazon (FireOS based on Android 11) and I was able to program micro:bit on my first try. That is why I assume that something is wrong with Lenovo tablet or Android on that tablet or Bluetooth. As already noted, Lenovo tablet was used to program micro:bit V1 and it worked fine.

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UPDATE. new micro:bit was loaded with different version of program, with "test", to test buttons, LEDs, tilt sensor, etc. We will retest with the new version of "meet-the-microbit-program".

[martinwork]

Thanks for interesting info. Do you have any details about that different program, like a download URL or a hex file we could try?

Please post the contents of the DETAILS.TXT file from the MICROBIT drive of the micro:bit V2.

It might be useful to post the precise model variant of the M10, like TB328FU / TB328FU_EEA / TB328FU_TR, and RAM size.

[PSLLSP]

I retested this issue and I confirm that Lenovo M10 tablet 3rd gen WiFi just cannot flash micro:bit V2... :-(

1. I flashed micro:bit V2.21 with program "meet the micro:bit". I flashed it from tablet Amazon Fire HD 10.

2. I tried to flash simple "heart" program from tablet "Lenovo M10". There were signs of some Bluetooth interactions but flashing process filed with error GATT WRITE NOT PERMIT

3. I flashed "heart" program from Amazon Fire HD 10, it worked

4. I repeated step 2 from Lenovo tablet, it failed again.

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I noticed some other issue with micro:bit application for Android (3.0.11). When I switch language of the application (from English to something else), I have to restart application (kill & start) otherwise it will not try to pair with micro:bit, it only saves files to tablet internal drive... Observed on Amazon Fire tablet. I noticed this in the past (3.0.10), I just confirmed it today. And I think there are some issues when I want to switch to other micro:bit, so Bluetooth pattern is different, that is difficult to switch to new micro:bit.

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One more note. I think it would be good idea to write some information to serial port in the application "meet the micro:bit", like device name and serial number, maybe even MAC address of Bluetooth radio and maybe you know other important info, like version of compiler used to build application or version of libraries. Device name is important, it is used for pairing process and when more devices are on the table I would like to have an easy way for reliable identification what device is what...

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I verified, that micro:bit V2.21 can be flashed from tablet Amazon Fire 8 HD 2018, it is an older tablet that has Bluetooth 4.1 LE and it works. I have no idea what is wrong with Lenovo M10 tablet... :-(

[martinwork]

I flashed micro:bit V2.21 with program "meet the micro:bit". I flashed it from tablet Amazon Fire HD 10.

It sounds like you Bluetooth flashed the "meet the micro:bit" program using the Fire tablet

In my comment above, it's significant for an ideal test, that a hex file is flashed from a computer via USB by dragging it to the MICROBIT drive, because that completely refreshes the micro:bit, including wiping any previous pairing information.

As well as both parts of the fresh start recipe, it might help to reset the tablet's Bluetooth as described in #79, or even as in this link, and reinstall the app.

It sounds like pairing works, but just to be sure...

• Does the error occur when pairing, or during flashing?
• Can you post a screenshot of the error?
• What do you see on the micro:bit display during and after whatever process creates the error?

Try each of the following after a fresh start.

• Pair via the Pair button on the app's homepage.
• Pair using the Android Settings app.

Assuming pairing works, test flashing with a fresh pairing, preferably in the app, each time (USB flash means... drag hex file to MICROBIT drive).

• USB flash a simple heart program, pair in the app, then try to Bluetooth flash a simple heart program.
• USB flash a simple heart program, pair in the app, then try to Bluetooth flash a program with the Data Logger extension, such as: https://makecode.microbit.org/#pub:_gHx1MJdJziaE

The change between simple heart and data logger will trigger a full flash rather than a partial flash.

It might be useful to post the precise model variant of the M10, like TB328FU, and RAM size. Quite a few Lenovo M10 3rd gens have the app installed with different models.

[PSLLSP]

I will try that. But it is just an inefficient way of troubleshooting. I am blind and I guess... Program for micro:bit to troubleshoot/diagnostic Bluetooth will be much better... micro:bit connected to PC with USB cable can report to serial line what it sees on Bluetooth, what messages it sent and what it received, it can report that a timeout was triggered. It can replicate flash protocol without flashing anything... Very detailed protocol could be created in such way. A long time ago, when devices were connected with RS-232/UART, I had some tools to troubleshoot serial communication. Bluetooth is much more difficult from this point of view but client program for micro:bit can help here. Such program has to be created by a top expert who understand micro:bit internals and knows Bluetooth protocol used by micro:bit.

[martinwork]

Other points would be best raised in separate issues.

When I switch language of the application (from English to something else), I have to restart application.

I can see this. I created an issue:
#83

I think there are some issues when I want to switch to other micro:bit, so Bluetooth pattern is different, that is difficult to switch to new micro:bit.

On the screen which asks you to check the pattern, there is a "My pattern is different >" button which routes to the pairing process.

One more note. I think it would be good idea to write some information to serial port in the application "meet the micro:bit", like device name and serial number, maybe even MAC address of Bluetooth radio and maybe you know other important info, like version of compiler used to build application or version of libraries. Device name is important, it is used for pairing process and when more devices are on the table I would like to have an easy way for reliable identification what device is what...

I am all for debugging things with serial trace, including Bluetooth! It is possible to build a hex that would give a lot of information from the micro:bit's point of view. We really need to know what's happening from the tablet's point of view, ideally by running the app on your tablet, to capture the Android logs (logcat) - easiest with Android Studio and running in the debugger.

The "meet the micro:bit" program is a MakeCode program.
Open ‘meet the micro:bit’ for V2 micro:bits in MakeCode
Open ‘meet the micro:bit’ for V1 micro:bits in MakeCod

Here's a zip with a hex file to output to serial and display, micro:bit's Bluetooth device address, name and pattern - I just wrote it, but I think it works.
bluetoothDeviceInfo.zip

[PSLLSP]

I loaded micro:bit V2.21 with program "meet the micro:bit", I flashed it from PC over USB cable. No difference, tablet Lenovo M10 was not able to flash the micro:bit.

Then I deleted Bluetooth pairing and power off the tablet. It is not my tablet so resetting network options was not an option...

I tried pairing with micro:bit V2 from micro:bit app and I think it works fine, there was a prompt from Android and I was able to pair it, it worked.

The issue is with flashing. When flashing fails, micro:bit V2 shows "+" sign.

DETAILS.TXT

# DAPLink Firmware - see https://daplink.io
Build ID: v0257-gc782a5ba (gcc)
Unique ID: 990636020005282039099c59f1333aee000000006e052820
HIC ID: 6e052820
Auto Reset: 1
Automation allowed: 0
Overflow detection: 0
Incompatible image detection: 1
Page erasing: 0
Daplink Mode: Interface
Interface Version: 0257
Bootloader Version: 0257
Git SHA: c782a5ba907377658bc28aa8d132a0fa44543687
Local Mods: 0
USB Interfaces: MSD, CDC, HID, WebUSB
Bootloader CRC: 0x725bea7d
Interface CRC: 0xe561f1de
Remount count: 0
URL: https://microbit.org/device/?id=9906&v=0257

Pictures, a lot of low quality pictures... I am sorry for AIDA64 in Czech language but I assume it should not be real issue for understanding what version of M10 tablet is the troublemaker...

[PSLLSP]

I have an unexpected update. Two days ago I reported that I can flash micro:bit V2.21 with older Amazon tablet (Fire HD 8 2018). I cannot do it today, I receive error GATT WRITE NOT PERMIT. micro:bit was flashed with "meet-the-micro", from PC and I cannot flash it over Bluetooth. There was some problem with RESET button just few minutes ago (#84 created). When I met this issue for the first time, micro:bit showed "X" on LED display but now it just stays in "Bluetooth pattern" mode.

[martinwork]

Usually, micro:bit displays a tick to confirms pairing completed as expected. An X means micro:bit detected a pairing problem. In that case Android might let you continue, but I think it's probably best to pair again.

[PSLLSP]

Update on Fire HD 8 2018. On the first try to flash micro:bit, micro:bit displayed "X" and later attempts to flash anything were just ignored, LED display showed only Bluetooth pairing pattern, no "+" or "X" was displayed.

I removed pairing on Android tablet and I did new pairing. After that I was able to flash program to the micro:bit. So, it looks like pairing information stored in micro:bit was damaged in some way. The issue with Amazon Fire 8 HD tablet was not the same as I see with Lenovo tablet M10.

[mpoelzl]

Has there been any progress on this? I also have Lenovo M10 tablets and the pairing works but the flashing always fails with " GATT WRITE NOT PERMIT".

We have 10 of these Tablets and need to use them with our micro:bits at the start of the next school year. On a different note, would it be feasable to add USB support for the Android app? We have the correct USB cables to attach the micro:bits but the app does not seem to support it.

[PSLLSP]

Update from my side is that the boy with Lenovo tablet lost interest in micro:bit. He found he can use his tablet to play some stupid games in his free time when he cannot play Fortnite and Minecraft on his Xbox...