Multiple Arduini to Smartphone

Hi,
I’m searching the appropriate method to connect 4 Arduini wireless with my Android-Smartphone.

To display values on Smartphone I would use an serial monitor App like this: https://play.google.com/store/apps/details?id=com.nudge.me.SerialMon&hl=en
The distance between Arduini and Smartphone would be between 3m to 5m (10ft to 16.5ft).
On each Arduino is connected only one sensor (Hall Sensor), whose values I want display on my Smartphone.
Therefore the amounts of data to send are little.
Would be nice to use Feathers like Feather Products Category on Adafruit Industries but it’s not stringent.
The information shall be displayed very fast.
The most important value would be the power consumption because of battery operation.

My first idea was to use BT (or better BLE) and pair all my 4 Arduini (Feather) with my Smartphone (see image ‘all_BT’).
But I think that Serial Monitor is able to display one connected Arduino only.

Therefore I have continued with my research and I have found several possibilities to connect Arduini over air (see image ‘one_BT`).

Since there are so many possibilities I have loosen the overview. :confused:

Which method would be the best to fulfill my requirements?
Which would you recommend?

Many thanks
Best Regards

AdaZus:
Therefore I have continued with my research and I have found several possibilities

I don't think there are, and "One BT" is not only the obvious choice but probably the only as, by having S1 collect data from the others and send that and its own out via bluetooth, it allows the phone to be used in the normal manner. This absolves you from coming forth with a phone app that does what is probably the impossible.

It also allows you to use NRF24s for an internal network, which makes more sense than using bluetooth.

Hi, :slight_smile:
With your advice I have continued with research…
As I have mentioned before I would use feather. They are fine for mobile use. (Battery management, all on one board, no problems with soldering or connecting together different break out boards.)

In consideration of this, I would do it that way… see scheme “one_BT_Feather”

But it appears new issues:

Need to understand …
…if serial monitor apps are compatible with this Adafruit BLE Feathers.
Apps like https://play.google.com/store/apps/details?id=com.nudge.me.SerialMon&hl=en and tutorial I have found are made for HC-06 Bluetooth break Out Boards.

…if all BLE- Feather work with my smartphones (HTC ONE S)

…what’s the difference between nRF52, M0 and 32u4.
As I´m beginner I would prefer a microcontroller which programmable with Arduino IDE and where most Arduino libraries work.
(It works with Arduino Arduino Board Testing | Bluefruit nRF52 Feather Learning Guide | Adafruit Learning System
But this posts confusing me… Adafruit customer service forums • View topic - Feather M0 vs 32u4)

… which would be the right sketch to connect my phone (via Bluetooth) to Feathers for my application:
Advertising: Beacon or
BLE UART: Controller

My application: I need to receive and to send information. Receive data via Bluetoth from Hall-Sensors and send data (+ and -) to make some calibration if it’s necessary.

I agree with @Nick_Pyner’s idea of gathering all the data onto one Arduino to simplify communication with the phone.

This Simple nRF24L01+ Tutorial may be of interest.

If you really need several Arduinos to communicate with the phone one option would be to run a web server program on the phone and communicate with it using WiFi - maybe just using ESP8266 modules. Or you could run the server on one of the ESP8266 modules. But unless you are familiar with web programming that would probably require lot of learning and a lot of work compared to what Nick suggested.

…R

If you want to use BLE, your phone needs to be BLE compatible. You can get an app to test this. All that Feather stuff seems over complicated, over-priced, and probably doesn't absolve you from learning to use a soldering iron anyway.

… which would be the right sketch to connect my phone (via Bluetooth) to Feathers for my application:
Advertising: Beacon or
BLE UART: Controller

Definitely not the first and probably neither. As I understand it, you just want to send serial data, and that requires no special code. Your code will be all about managing the data sources.

I can't comment further on BLE, other than that I hear rumour that only BLE-specific apps can be used on the phone. I only use HC-05 and HC-06.

Read replies #3 and #1 again.