Data Sheet

2 MODULE INTERFACES
5
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Pin number
Symbol
I/O type
Function
6
GND
P
Power supply
reference ground
7
3V3
P
Power supply 3V3
2.3 Definitions on test points
Pin number
Symbol
I/O type
Function
-
CSN
I/O
It’s a mode
selection pin. If it
is connected to
ground before
powered on, enter
the firmware test
mode. If it is not
connected or
connected to VCC
before powered
on, enter the
firmware
application mode.
Correspond to
P21 of the IC
-
RST
I
Hardware reset
pin; by default,
high level; active
low
-
TX1
I/O
UART1_TX, user
serial interface
-
RX1
I/O
UART1_RX, user
serial interface
-
TX2
I/O
LOG TX