user54212: I want to make an IOT project using an Arduino nano and I need heart rate sensors. I I have a miband2. So, is it possible to connect them ? 

user55109: You need to connect as a central device.
I've had good luck with the adafruit nrf52 feather.  Also see: https://github.com/Freeyourgadget/Gadgetbridge for the protocol.

54212: <p>I want to make an IOT project using an Arduino nano and I need heart rate sensors. I I have a miband2. So, is it possible to connect them ? </p>
 55109: <p>You need to connect as a central device.
I've had good luck with the adafruit nrf52 feather.  Also see: <a href="https://github.com/Freeyourgadget/Gadgetbridge" rel="nofollow noreferrer">https://github.com/Freeyourgadget/Gadgetbridge</a> for the protocol.</p>
