AnsweredAssumed Answered

Is it possible to add a 1-byte header to BT packets?

Question asked by Garcia.Amy on May 24, 2017
Latest reply on May 24, 2017 by Garcia.Amy

My customer would like to use BTLE as just a "wire" replacement. However, we recently discovered that the Android BT stack / Phonegap will sometimes deliver BT packets to our phone-app in a different order to which it received them off the air, so we are forced to add a 1 byte header on each BT packet we transmit from our device to give us the information to reorder them once they are received on the phone.

We would need the ability to add that one byte header on BT packets, and that would have to be inside the BT chip since the packet boundaries are only decided there.

     The change is trivial and tiny - I only mention it since this means the code that does the packetization on the BT device cannot be in ROM (OTP or Flash is fine) so we can add this small delta to it.

 

BTLE (at least in the mode we use it) relays data in 20-byte packets, and so somewhere in the stack the data-stream is broken up into chunks of 20 bytes.  We need the code that does that to only take 19 bytes from the data-stream and put that with a 1 byte counter into the 20-byte packet (a very simple change so we can do it ourselves if we have the source code, or it should not take more than 1 hour if someone else does it).  I have seen BT chips that store the stack-code in RAM (compiled in with the application) / Flash / OTP / ROM, all of these except ROM would work for us since it would allow the change.

 

Is this possible with the BLUENRG?

Outcomes