I am designing a home automation project. I want to control different home appliances through GSM. I am designing it in such a way that each apparatus is connected to an Arduino and bluetooth module. There is a master unit with Arduino, Bluetooth and GSM modules. When the user sends a message, the GSM receives it and communicates via Bluetooth to the corresponding Bluetooth module and Arduino.

Is it possible to communicate between two Bluetooth modules of two Arduinos? Is there a better solution?

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    Your GSM-connected arduino may need to connect and disconnect its master bluetooth module with the corresponding slave bluetooth devices as needed, but it should definitely be possible.
    – Dave X
    Commented Dec 13, 2015 at 15:38

3 Answers 3


I'm not sure how many bluetooth devices can be connected to your smartphone. But if you use smartphone, the you can eliminate the master Arduino. But as I said, it still depends on the number of devices you'd like to control. This is supposed to go in the comment section.


How about little smart WiFi boards (such as Red Bear WiFi Micro or something similar), which are connected at your local home network? You can configure your own dyndns service or use a existing and built a web home appliances or web service for your own mobile application. In general please take care of security aspects, so that your home can not be manipulated...


You connect your different sensors or devices to many slave arduinos and each slave arduino has its own bluwtooth module that send the data to Master Arduino that contains the Bluetooth and GSM Module.

And yes you can connect max 7 bluetooth devices to 1 Bluetooth module at a time so in that manner you can connect 7 slave devices to Master Arduino

  • FYI this system is called Bluetooth Piconet and is not supported in many devices. Most likely needs more expensive bluetooth modules.
    – Avamander
    Commented Feb 1, 2016 at 14:53

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