The best way to connect to over 200 low-power devices

[under_pressure]

Hello All!

I have a question regarding Bluetooth. What is the best way to get data from 200 low-power bluetooth capable devices?

Assumption 1: All of them will use nRF52832

Requirement 1: Nodes should consume as little power as possible

Requirement 2: Nodes are measuring something and need to send this data periodically to a hub

Shall I use ANT for this number of devices or will Bluetooth Smart be able to handle this?

Thanks a lot for help!

under_pressure

[Jørgen Holmefjord]

I would not recommend using ANT. ANT does not support more connections than Bluetooth does.

There are (at least) two different solutions to your issue, both using BLE. I assume that your hub does not have low power requirements?

1. Advertising Beacons and scanner - Setup the nodes to advertise the sensor data at a high advertising interval. You can use the nRF52 Online Power Profiler to check the current consumption of different configurations in this mode. The hub will be constantly scanning for advertising packets and collect the sensor data from all nodes.
2. The latest s132 softdevices support up to 20 concurrent connections. Within 5 minutes you should have plenty enough time to connect 20 nodes, collecet the data, disconnect, and connect the next 20 nodes until you have cycled through all 200 nodes.

Best regards,
Jørgen

[under_pressure]

Thank you very much for the answer! 

Then I see that I will need to go for bluetooth. The second solution you mentioned assumes that all of those 200 devices are paired before with the hub, is that correct?

Yes, the hub does not have low-power requirements. 

[awneil]

under_pressure said:

Bluetooth Smart

That name was discontinued a couple of years ago - it's now just BLE

under_pressure said:

assumes that all of those 200 devices are paired

No - it is not necessary to pair before connecting.