Best way to connect multiply arduinos wirelessly

Projects General Guidance
1

Hey folks,
I need some advice here. I'm doing this science experiment for my kids where i have two sensors in sealed containers, i need to be able to see data from both sensors on my phone via bluetooth. In your experience what the best way of doing this?
Here is a diagram of what im trying to do.

[Album] imgur.com

I only see three options of how to do this and i don't know which one is better

  • I could give sensor 1 both a slave and master Bluetooth device and have sensor 2 be only a slave. With this im worried about not having enough pins, since im only using a nano and i also need space for the sensor
  • Second option is similar to the first, but we use wifi to connect the two sensors and have a master sensor that connects to the phone via Bluetooth. So i guess which option is easier to set up from an end user perspective?
  • Last option im not sure is feasible? can we connect both devices directly to the phone, and read data coming from it simultaneously is this allowed by the Bluetooth protocol?
2

IFF the sensors are in individual containers:

  1. Nano1 has sensor1 and two blueteeth, one for the phone and one for the other nano with sensor2 and a bluetooth. That's three blueteeth in all, but the phone only has to deal with one.

2.In that event, why not use WiFi to connect to the phone?

  1. Probably not. Look for the phone app first.
3

Nick_Pyner:
2.In that event, why not use WiFi to connect to the phone?

hmm, i wanted the project not to have to depend on having a wifi network.

I basically want to emulate how airpods connect to your phone, where you are only dealing with a single Bluetooth connection.

4

With BLE (which most phones have) you can apparently do all sorts of interesting things with multiple devices but I have not yet found a tutorial that explains how to do it with Arduinos.

Note however that the HC05 and HC06 modules that are commonly used with Arduinos cannot do BLE.

Another option might be to use ESP8266 devices (such as the Wemos D1) which have WiFi as standard.

...R

5

I think an Android app could be designed to poll each BT in turn. This might occur at such a speed that to the user it appears like it's talking to both simultaneously.

I've made an app that automatically connects to a BT specified by an address.

Don't see a problem in connecting to Nano1, grabbing its data, disconnecting, then connect to Nano2, grab its data, back to Nano1...and so on at whatever rate you need.

You could also provide buttons on the phone screen for the user to select the sensor to read.

John.