NRF24le1 max no. of IR nodes?

[Matthews]

Hi friends,

I am doing a project in NRF24le1 using RF communication with multiple nodes with a host using star topology.

Could you suggest a Protocol that supports connecting upto 100 nodes with a single host

[ovrebekk]

Hi

We don't really have any out of the box-protocols well suited for doing huge star networks, you would probably need to do something proprietary on top of the ESB protocol.

If you have a single host talking to multiple nodes then you can have the host interrogate one node at the time, and differentiate the nodes by using unique RF addresses.

If you use the ACK payload mechanism you can have the nodes prepare some data for the host in an ACK payload, and as soon as the host sends a packet to the node the ACK payload will be sent in return.

The simplest implementation would have the nodes in RX mode constantly, waiting for the host to send a packet, but this wouldn't be very power efficient. If you need a more efficient implementation you can have the host interrogate the nodes at a fixed interval, allowing the nodes to sleep in between packets.

Best regards
Torbjørn

[ovrebekk]

Hi

I don't think we have any simple examples for this unfortunately. You might be able to use Gazell, but I think it is simpler by just using ESB.

The basic operation would be something like this:

1. For X devices, prepare a list of unique addresses for each device.
2. Configure each PRX device with it's own unique address from the list.
3. On the host side, go through each address in the list and do the following:
   4) Change the host TX address and RX PIPE0 address to that of the device you want to talk to.
   5) Send a packet to the device with any new information you have for the device
   6) On the device, add any data for the host into an ACK payload
   7) Have the host send another packet to pick up the ACK payload from the device
   8) Repeat from 4, until you have gone through the entire list of devices.

Best regards