Maximum data chunk lenght when calling bleprofile_sendWriteReq|Cmd

[Anonymous]

Hi,

I just found out that my attempt to write to a gatt server with bleprofile_sendWriteReq() works when I'm only writing 4 bytes but not when I'm writing 26 bytes (causes system reset). Did I hit a hard limit, or is there some maximum transfer unit which I can configure?

Regards,

Kilian

[MichaelF_56 · Accepted solution]

The standard process for reading and writing the GATT database maxes out at 22 bytes.

Take a look at the long_characteristic example in SDK 2.X

This sample application demonstrates how to read and write values to a characteristic value larger than 512 octets in length.

You will find this thread helpful as well: Support for very large characteristics

[Anonymous]

I should have been more specific, I'm writing from a BCM20737S in a central role to another BCM20737S in a peripheral role. The long characteristic example only explains the server/peripheral side. Fortunately I can reduce the transfer size to 22 Bytes.

Regards,

Kilian