Product package contains two HC-05 bluetooth modules.
The simplest way to make two Arduino boards talk to each other wirelessly.
Connect each of these modules to two different Arduino boards. When both of them are powered up, they will connect to each other automatically, no matter which one you power up first. Then any data sent from one Arduino board will be tranfered wirelessly to another and vice versa.
Connects Automatically, No Interference:
We’ve already paired these modules with each other before packaging, with a unique pairing code. Because of the unique code, there’s no chance of interference if two or more pairs of these modules are working nearby.
No Program Upload Error:
Unlike generic HC-05 module, both of these modules have a diode isolation circuit. So, while connected to arduino TX0 and RX0 pins, you can upload code to arduino without any error.
The TX and RX pins of the modules work on 5V (won’t work on 3.3V). But the power pin has to be connected to 3.3V (don’t put 5V to the 3.3V pin)
Applications: Remote controlled robots, wireless communication between two Arduino boards.