About nRF52840 communication scenario

[Ekmekci]

Dear Devzone members, 

I need your suggestions about one thinkg.

I am trying to do sensor networking with nRF52840 tags.

I have 15 slave, 1 master. All slaves work with battery. So, power consumption is very important for me.

Distance is max 60meters from furthest slave to master. So, i dont have any distance problem

Which scenario i should use;

1) Communicate all 15 slaves each others with mesh topology. After all, i send full data from any of slave to master.

2) Sending data from all slaves to master seperately. 

I am waiting your opinions and suggestions.

Best regards,

[Hung Bui]

Hi Ibrahim, 

Could you give some more information about the environment ? You mentioned 60m from the furthest slave, but it's outdoor or indoor ? Is there any obstacle, wall ? The range can vary a lot due to the environment. 

How is your slave located ? What is the distance between them ? 

I assume the communication is only from a slave to the master (both direction ? ) not between slaves ? 

From what you described, I don't think mesh topology would be ideal. Mesh would require you to have a number of nodes with main-powered to act as the back-bone of the network. 

You can think of using normal BLE star topology with +4dbm or +8dbm output power. Or can think of using proprietary ESB protocol for example. 

[Ekmekci]

Dear Hung, 

Thank you for your attention, you are totally right. I gave small information for describe environment.

Let me try another way,

I have room, room is rectangular. I have also temperature sensor nodes which located different point inside of the room.

I just want to collect these temperature datas via central (master) unit.

Communication will be both direction because when slave send data if master receive correctly, master will send ack data.

All slaves in the room, indoor but there is no obstacle.

Best regards,

[Hung Bui]

Thanks for the information. In that case if your number of sensor nodes wouldn't exceed 20, you can use normal BLE with one central and up to 20 peripherals. The peripherals can either keep the connection all the time, or can sleep most of the time and wakeup, establish a connection, transfer data and sleep again. 

If you want to simplify the protocol, you can think of using ESB. It will be lower power consumption, but there isn't any channel hopping, of time synchronization. 

No need for mesh here.