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BLE SPP example magic numbers

Posted: Tue Nov 27, 2018 2:26 pm
by PeterR
The BLE SPP server example sends up to "mtu-3" bytes using esp_ble_gatts_send_indicate().

Why mtu-3 and not the all the available mtu?

Re: BLE SPP example magic numbers

Posted: Tue Nov 27, 2018 3:34 pm
by chegewara
Because 3 bytes are reserved for indication message OP code or something like that in lower layer driver. It can be found in bluetooth core specification if you really need it.

Re: BLE SPP example magic numbers

Posted: Wed Nov 28, 2018 10:23 am
by PeterR
Thanks.