Adding a wireless connection to your Arduino projects opens up a whole range of new possibilities. In this tutorial we'll use a an HC-05 or HC-06 module to add a Bluetooth connection so we can send and receive data through a mobile phone app.
I'll show you how to wire in the module, some tips on what serial ports to use to connect the Arduino to it and then write a simple sketch to show the Arduino talking to your phone over the Bluetooth link.
Don't forget to visit my website for circuit diagrams, code downloads and hints and tips.
https://bytesnbits.co.uk/adding-bluetooth-to-your-arduino-projects/
Bluetooth Modules
Amazon:
HC-05 module : https://amzn.to/3t6CjZE
HC-06 (slave only) : https://amzn.to/3iY3jpE
eBay:
HC-05 : http://ebay.us/lUhUPn
HC-06 (slave only) : http://ebay.us/I4cPwi