Bitcraze Forums

I'm installing NuttX on the STM32F405 and try to read the syslink communication packets that are sent from the NRF.
I found your document on the protocol. However what I receive has not this form at all.
Is one package consisting of START,TYPE,LEN, DATA, CKSUM or are these blocks send individually?

What I receive are messages consisting of [3,4,3,12] bytes repeatedly, so something like this
3bytes,4bytes,3bytes,12bytes,3bytes,4bytes,3bytes,12bytes,3bytes,4bytes,3bytes,12bytes,3bytes,4bytes,3bytes,12bytes

You can see the protocol https://github.com/bitcraze/crazyflie2- ... /syslink.c and message types https://github.com/bitcraze/crazyflie2- ... /syslink.h

They are always sent with start length type and checksum. Do you have an hex-dump of what you are seing on the uart? That would help analysing what is going on. There is a couple of messages (like power management and rssi) that are sent at regular interval through syslink.

OK thank you. Apparently even though the data is sent as packages, they are not received as full packages. So I had to collect data until everything is done.

Glad I could help. The UART does not provides framing (not the way we use it at least), so listening to all bytes and detecting the start is indeed the only way to go.