How to turn on/off mesh

[sphudson]

I am using the RBC mesh in a networking product using the nRF51422. We would like to turn the mesh on and off at selected times, say once per hour for a minute or two. I know how to turn on (init) the mesh. But, what is the best way to turn it off such that the radio is at minimal power?

Thanks in advance --s

[Trond Einar Snekvik]

Unfortunately, no. When turned off, the mesh doesn't use the radio at all, and will not be able to send or receive anything. The mode you're requesting requires a surprising amount of extra functionality, as the battery powered node cannot be in RX mode constantly (it's extremely power consuming). Therefore, the "router" node has to buffer all incoming messages while waiting for the end-node to attach in some low-power fashion, like a regular BLE connection. This is the approach I would recommend for the mesh; let router devices scan for end node's advertisements, and connect. Transfer all data since the last connection, and disconnect again. Alternatively, keep a connection running, but keep the connection interval high, as to conserve power in the end node. If you want several end-nodes at each router, you should make the router the master in the connections (requires SD120 or SD130).

[d21d3q]

How about waking up end node (some sensor) from deep sleep, ask some Master through mesh for instructions (to transfer some data) and go back to sleep? In this case question is if end node needs to discover network on reconnection as ZigBee does?

[Trond Einar Snekvik]

That seems reasonable. If you don't want to push data to the sensor, you can actually do this only by advertising, if you follow the packet format. Enabling the mesh will force you to do some scanning, and it might take up to 100ms to get a response from the master, but it's not an unreasonable approach. The end node does not need to reestablish its network role, or negotiate some slot from the master in any way. It can wake up, send, and go back to sleep, without any management overhead.