I've managed to successfully increase BLE MTU Size and Data Length on a 52840 to 247 and 251 respectively.
This works fine with BLE Notifications on a recent MacBook Pro with Bluetooth 4.2 (it negotiates to 247 and 251) and I can transfer 244 bytes at a time
However on an Mac Pro (late 2013) which is Bluetooth 4.2, mtu and data length negotiation, negotiate to 247 and 27 respectively.
When I then try to send a notification of 244 bytes in length, it's truncated to 101 bytes (i.e. an MTU of 104 bytes).
However equally confusing, Bluetooth 4.0 suggests that the MTU size is 23 bytes.
So why:
a) Is Bluetooth 4.0 capable of a large MTU size than expected?
b) Why is data getting truncated at 101 bytes when 244 has been negotiated successfully?
c) How can I get the mtu negotiation in the erf sdk to negotiate the correct size or identify it's a Bluetooth 4.0 device?
Thanks