Peer to peer and centralized communication

RE: Peer to peer and centralized communication

ovrebekk — Thu, 24 Mar 2022 11:56:48 GMT

[quote user="sAz-n"]So does it mean that each channel uses a different frequency, but the receiving/sending components are the same, and therefore asynchronous communication is not possible?[/quote]

Essentially, yes. The radio can not send and receive at the same time, nor can it receive on two different frequencies at the same time.

In order to change from one frequency to the next you need to power the radio down and up again, which takes about 130us.

I won't say asynchronous communication is impossible, you just have to expect that not all the packet will be received, and design the protocol accordingly (by using the retransmit feature of the ESB protocol for instance).

[quote user="sAz-n"]Can a node communicate asynchronously using two different nrf51 devices? [/quote]

I assume you mean using two different nRF51 devices on the same board?

This is possible, then you would be able to receive on two different frequencies at the same time. Just be aware that if one of the devices are transmitting it will most likely block out reception on the other device (even if they are using different frequencies), because the two devices would be in close proximity of each other.

Best regards
Torbjørn

RE: Peer to peer and centralized communication

sAz-n — Wed, 23 Mar 2022 15:11:09 GMT

So does it mean that each channel uses a different frequency, but the receiving/sending components are the same, and therefore asynchronous communication is not possible?

Can a node communicate asynchronously using two different nrf51 devices?

Best

RE: Peer to peer and centralized communication

ovrebekk — Mon, 21 Mar 2022 12:53:11 GMT

It should not be a problem to use different RF channels for the peer to peer and the peer to central communication respectively.

It only means that the peers need to switch between the different channels as needed.

The main problem of this method is if the peer needs to listen for messages from other peers and the central asynchronously, since you will not be able to listen on two different channels at the same time. In this case you would have to switch channels back and forth on a timer, and accept a decent amount of packet loss.

Best regards
Torbjørn