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[Andhika]

Hi,

I'm currently wprking on my project, my project it's about swarm, before the master swarm can advertise the message to the slave swarm through blehandler function now we want to develop so we can send order from smartphone to the master, I'm facing the problem that the smartphone can't detect the connection because of blehandler function, can ble advertise to slave device while it established a connection with smartphone? should i build a Thread or a mesh?

[haakonsh]

We need you to rephrase your question because it is very difficult to understand what it is you want. 

What is a swarm?

"I'm facing the problem that the smartphone can't detect the connection because of blehandler function"
- what are you talking about here, what is the context? 

"can ble advertise to slave device while it established a connection with smartphone?"
You can use directed advertisements while in connections with another devices. The S140 supports up to 20 concurrent links, so that should not be an issue.

"should i build a Thread or a mesh?"
That depends on your use-case. What is your use-case, what is it that want to achieve with this project? 

[Andhika]

Hi haakonsh,

I'm really thankfull for your help, so my project is to advance the previous project it's about Drone-Swarm (so more than one drone with concept master and slave) the previous project has a function called BLEhandler that send message over BLE such as position etc. and now my job is i want to establish a connection with a smartphone so we can send an order such on/off, fly, back and forth to master drone. as i want to buid the connection with smartphone there is an interference from function BLEHandler, which i believe it advertise the message to the slave, so the smartphone can't detect my board, but if i comment the function it can detect my board.

but thanks you've answered a half of my questions.

"can ble advertise to slave device while it established a connection with smartphone?"
You can use directed advertisements while in connections with another devices. The S140 supports up to 20 concurrent links, so that should not be an issue.

any suggestion how to do it?

I sincerely appreciate your help.

[haakonsh]

If you have fewer than 20-30 devices then a pico-net using BLE is perhaps the best solution, above that number, I believe BLE Mesh might be better. 

It depends on what your requirements for the wireless links are. If you only need to send abstract commands and basic telemetry like battery service, GPS position, etc, and your latency requirements are not strict then a mesh network is a good idea. The throughput will be low, the latency will be high, but the wireless range and scalability with regards to the number of units in the network will be better in a meshed network. 

I do not recommend routed meshed networks like Thread and Zigbee as the time it takes to rebuild a routing table varies from ~30s to several minutes, even for small networks. This is important because if one router is lost to the network, due to an empty battery, FW crash, or it has simply moved outside of the wireless range, the routing table will have to be rebuilt before you can send data between devices. This is not an issue for flooded meshes like BLE Mesh that does not rely on a routing table but rather retransmitted broadcast/omnicast messages. 

I do not believe there are any smartphones that support Thread or Zigbee, but there is support for connecting to a BLE Mesh network through a Proxy Node. A proxy node can communicate via a regular BLE connection at the same time as being a part of the Mesh network. 
 

[Andhika]

Thank you for your fast respond we just have 3 Drones, and the commands that we send is to on/of the drone give order to fly back and forth and so on, is it still possible to do it with ble?

i am really gratefull four your kindness.

[haakonsh]

Oh, in that case, BLE is by far the best option. 

We have a simple example that lets you create a virtual UART over a BLE link, UART/Serial Port Emulation over BLE. You can also create your own service and characteristics. 

Our BLE stacks, the SoftDevices can support up to 20 concurrent links, so 3 links are not a problem.