Packets Size less than MTU size

[dayizhang]

Hi. I am using nrf52840 with Softdevice 16.0.0.

I set the maximum size to 247 bytes. But I probably only need 68 bytes per packet.

Should I reduce my MTU size to 71 or I can keep 247 bytes?

[Vidar Berg]

Hello,

You can keep it at 247 bytes if you want. The drawback is that the Softdevice will require more RAM, but that should not be a problem if you have enough RAM to spare.

[tlgage]

dayizhang curious, are you able to actually send less than your current MTU size at a time doing a Notification? I am trying to work through a similar issue myself here, https://devzone.nordicsemi.com/f/nordic-q-a/73952/ble-using-notify-of-length-less-than-current-mtu-size-issue . but as of now all those Notifications are not allowing me to send anything less than the current MTU size, which seems incorrect behavior to me. 

[dayizhang]

Yes I can.