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dparson55 / NRFLite

nRF24L01+ library with AVR 2 pin support, requiring very little code along with YouTube videos showing all available features.
MIT License
160 stars 26 forks source link

Question: Can you send a message without a receiver address? #75

Closed mvoss96 closed 2 years ago

mvoss96 commented 2 years ago

Hi, Is it possible to send some kind of broadcast message without defining a receiver address?

I would need this functionality to implement dynamic binding of a sensor node and a receiver. So on first boot the sensor would just broadcast a greeting message and the receiver node would then answer with its own address

dparson55 commented 2 years ago

The nRF24L01 doesn't have such a feature, part of its internal workings is to discard any packets it receives that do not match its assigned RX address(es). Also on the TX side the nRF24L01 needs an address to send to; it is required since it places this address in the header of the packet it generates and sends.

It's easy to work around this limitation though by assuming the receiver is one of a set of possible addresses and attempting to send a packet to each address until an appropriate response is received. NRFLite only supports radio id's (addresses) from 0-255, so it wouldn't take long to send to every single one of them if you didn't want to limit the receiver to a smaller subset.

mvoss96 commented 2 years ago

thank you for the response