I have a project using nRF24L01 that can have multiple paired links operating in the same space. Each tx node must be able to link to any other rx node and each rx node able to link to any tx node. A link will only be one tx node with one rx node.
I am thinking that during simultaneous power on tx/rx node pair needs to establish channel/address. After this the pair will stay with that channel/address. Only after simultaneous power on will a new channel/address be picked. When I say simultaneous I really mean within a few seconds. If one of the pair is power cycled it will stay on previous channel/address.
Does anyone have any ideas for establishing links in this type of environment?
Has anyone created a protocol for frequency hopping with nRF24L01?
I haven’t seen on here that anybody has done any frequency hopping with the L01’s. It’s possible that it has been done on some of the other radio modules, though, or that somebody has implemented the solution and not posted it on the forum.
The library files that I have written for the 24L01’s will handle all the setup and TX/RX duties, all you have to do is handle the frequency hopping algorithm. For that, I would suggest buying a book on the subject or even taking a class in it if you are at a university that offers one.
andersonj55126:
Does anyone have any ideas for establishing links in this type of environment?
You could use the IEEE 802.15.4 MAC and perhaps ZigBee as models if you are of a mind to roll-yer-own. This is a DSSS system, not a hopper. A very few systems do hopping (FHSS) when long battery life is paramount. There are some tricky ways for every node to keep time-synch with all others so it can hop correctly - but no standard yet. Dust, Inc. is one of a few that have this in their proprietary products with FHSS.
Most products are using frequency agility (every node changes channels at the direction of a master coordinator), to cope with persistent interference. But since WiFi and most data radios use CMSA/CA, the use of FHSS is increasingly rare.
Complete modules with '15.4 and ZigBee are pretty inexpensive and available from several suppliers.