I'm using nRF24L01+ 2.4GHz Wireless Transceivers with the RF24 library to communicate between a bunch of Nanos.
The scheme is that the nanos are organised to form a tree structure. Each Nano has a single address which it listens to by reading pipe 1. Each Nano has a single parent address to which all outgoing messages are sent. Each Nano is designed to act as a relay by forwarding any messages received on pipe 1 to its parent. This works, but has some unexpected behaviour:
In a scenario where there are two Nanos with a common parent (and no other Nanos running), each child Nano receives on pipe 0 the messages which its counterpart sends to the parent. The only way I can explain this is that each Nano is implicitly listening to pipe 0 (the writing pipe) when I call radio.startListening(), even though I have never called radio.openReadingPipe(0,...).
The documentation includes this comment which implies that there is an interaction between reading and writing on pipe 0 but there's nothing to suggest that opening pipe 0 for writing also opens it for reading from the written address:
* @warning Pipe 0 is also used by the writing pipe. So if you open
* pipe 0 for reading, and then startListening(), it will overwrite the
* writing pipe. Ergo, do an openWritingPipe() again before write().
The sketch demonstrating this is quite complex and I haven't cut this down to a minimal example yet, but before I do is there anyone who has used RF24 with multiple senders to a common receiver, and if so did you see this behaviour?
Edited to add: It may be significant that I'm also using Ack payloads for each reading pipe.