Chengdu
Copyright ©2012–2019
，
Chengdu Ebyte Electronic Technology Co.,Ltd.
6
3. Size and pin definition
No.
Name
Direction
Function
1
GND
Module ground wire
2
GND
Module ground wire
3
GND
Module ground wire
4
GND
Module ground wire
5
M0
Input
（
pull up when
it’s weak
）
Cooperate with M1 to determine 4 operating modes of the module(can be lifted
floating, the module contains pull-up resistor
）
6
M1
Input
（
pull up when
it’s weak
）
Cooperate with M0 to determine 4 operating modes of the module(can be lifted
floating, the module contains pull-up resistor
）
7
RXD
Input
TTL serial input, connect to external TXD output pin;
8
TXD
Output
TTL serial input, connect to external RXD output pin;
9
AUX
Output
Used to indicate the working status of the module; the user wakes up the external
MCU and outputs a low level during the power-on self-test initialization
10
VCC
Module power supply positive reference, voltage range: 2.6V ~ 5.5V DC
11
GND
Module ground wire
12
NC
13
GND
Module ground wire
14
NC
15
NC
