Chengdu Ebyte Electronic Technology Co.,Ltd.
Co
pyright ©2012–2021，Chengdu Ebyte Electronic Technology Co.,Ltd.
6
3 Size and pin definition
Pin No.
Item
Direction
Description
1
TO
output
Used to indicate the working status of the module; the user
wakes up the external MCU , and outputs a low level during
the initialization of the power-on self-test; (can be suspended)
2
VCC
enter
Power input 5.0V
3
M0
Input
( very weak pull-up )
Cooperate with M1 to determine the 4 working modes of the
module (not floating, if not used, it can be grounded)
4
GND
-
power reference ground
5
M1
Input
( very weak pull-up )
Cooperate with M0 to determine the 4 working modes of the
module (not floating, if not used, it can be grounded)
6
NC
-
-
7
NC
-
-
8
NC
-
-
9
GND
-
power reference ground
10
SWD_DI
O
input \ output
Program download data interface ( the module needs to be
reset or erased before SWD programming )
11
RXD
enter
TTL serial port input, connect external TXD output pin
12
SWD_CL
K
input \ output
Program download clock interface ( the module needs to be
reset or erased before SWD programming )
13
TXD
output
TTL serial port output, connect external RXD input pin
