Parts · Boards

Bluetooth module HM-10

HM-10 (BLE)

Gives the Arduino Bluetooth: it sends and gets text over a serial line.

2Use it

Pin or leg	What it is for
VCC	+ power (5 V on most boards: read the label)
GND	GND
TXD	to the Arduino’s receive pin
RXD	from the Arduino’s send pin, through a divider (1 kΩ and 2 kΩ)

TXD goes to the Arduino’s receive pin, RXD to its send pin: the two lines cross.
RXD takes 3.3 V: the Arduino’s 5 V goes through the divider.
Send and read text at 9600 baud.

Pins	VCC, GND, TXD, RXD
RXD	3.3 V: from the Arduino through a divider

HM-10 copies	look the same; some commands differ
HC-05, HC-06	older Bluetooth: phones’ Bluetooth Low Energy apps do not see them