RE: nRF24L01+ Address byte order

Carlos Cuevas — Wed, 09 Oct 2013 22:52:29 GMT

What would be the best MSB (the one after the preamble, as cleared here) for the address in which the packet-error-rate is minimal?

I just spent 4 hours debugging to find out that my address was the one causing problems.

My application idea is to use 5-byte addressing but leave the MSByte constant for all of my devices, so the "internal" addresses of my sensor network would be 4 bytes long.

I picked 0x48 as the constant MSB and had one device as PRX with address 0x48DDCCBBAA obviously DDCCBBAA was just a made up address to start coding the communication libraries.

I found out that it was a terrible address, near 99% packets lost having the modules about 50cm apart, I switched the address to 0x481D1C1B1A (again, 1D1C1B1A was made up) and suddenly just 20% packets lost (I want to think due to interference with wifi networks around) a huge improvement!

I would like to know what would be the best constant MSByte in order to avoid as much as possible lost packets.

I'm amazed at the suceptibility of the address value. In the field, this address is going to be generated randomly but would greatly appreciate if there are more detailed guidelines about choosing a strong address, maybe some algorithm which determines how strong a given address is, which also explains why some addresses cause high lost package counts.

Thank you very much! Over all, the nRF24L01+ is a great little chip!

RE: nRF24L01+ Address byte order

Carlos Cuevas — Tue, 08 Oct 2013 12:54:31 GMT

Thanks for clearing it out Håkon!

RE: nRF24L01+ Address byte order

Håkon Alseth — Tue, 08 Oct 2013 10:37:41 GMT

Hi,

If you set your address in firmware to: E3 59 59 59 53

The way it goes over the air is: 53 59 59 59 E3

The last byte you set in firmware is the first one to go on-air. This byte should not be 0x00/0xFF/0x55/0xAA.

Best regards Håkon