How to send the BLE notification or data write of size 200?

[Keyur]

Hello,

I am using BLE peripheral. I want to send more than 200 bytes of data to the mobile phone. What I need to do in the characteristic definition and after that.

Thanks

Keyur

[Hung Bui]

Hi Keyur, 

You can send up to ATT_MTU-3 bytes with notification. If the attribute is larger than that it will be truncated. 

So if you want to send 200bytes in a notification you would need to request larger ATT_MTU. Please have a look here and here

If the peer device doesn't support large ATT_MTU then you may want to split the notification into multiple segment or use read command instead. 

In our SDK the ble_app_att_mtu_throughput demonstrate an example using large ATT_MTU.