WM620 Hardware User Guide
V1.1
All rights reserved by Shenzhen Neoway Technology Co., Ltd.
Page 11
2.6 UART
Pin
Pin Name
I/O
Function description
Note
52
CTS
I
High-speed UART clear to send
signal
53
RTS
O
High-speed UART ready for receive
signal
54
RXD
I
High-speed UART receive data input
(allow input 3V)
55
TXD
O
High-speed UART transmit data
output
2.6.1 Basic Descriptions of UART
UART1 is for AT commands, data sending/receiving, firmware updating, etc.
As a DCE device, the module is connected to DTE as shown in Figure 2-11.
Supported baud rates are 1200, 2400, 4800, 9600, 19200, 38400, 57600, 115200, 230400bps, and the default is
115200.
Figure 2-11, Connection between DCE (module) and DTE
The UART of WM620 works at 2.6V CMOS logic level. The voltages for input high level should not exceed
3.0V.
2.6.2 Level Translators for UART
If the UART is interfacing with a MCU that has 3.3V logic levels, resistors should be connected in series with
the signals, shown in figure 2-12.
