Python 'bleak' for Windows 11 can't write greater than 20 bytes to BLE characteristic

[mbacani_fluid]

Hi, I'm not too sure if this is the best place to look for answers to this but if anyone has had a similar issue any help would be greatly appreciated. 

I've been having an issue with writing greater than 20 bytes to a BLE characteristic. This issue only occurs when using 'bleak' for windows and so doesn't occur when using for example the nRF connect app. I thought this would be due to the MTU size but when using 'bleak' to check the MTU size it says it is 247 bytes. 

Would it be an MTU size issue or something else? If this isn't the best place to be asking this question could anyone direct me to another site? 

[Hieu]

Hi mbacani_fluid,

Are you using our SDK in the connection? If you are using it, can you setup logging to make sure the MTU of the connection is 247?

I see that information about the community behind bleak is available in their Contributing page: https://bleak.readthedocs.io/en/latest/contributing.html.

Hieu

[mbacani_fluid]

Hi Hieu,

I am using the nRF SDK and I did make sure that the MTU size was 247 bytes in logging. I'll also post about it in the bleak community. 

[Hieu]

Hi mbacani_fluid,

I hope the bleak community would be able to find the root cause. It seems like a great project.

Please feel free to ask if you have any questions about the nRF side.