Yuga CLM920 TE5 LTE Module Hardware Manual

CLM920_TE5 LTE Module Hardware Manual
22
YUGA Information Technology Co.,Ltd
Module
GND
RTS
TXD
RXD
Host
GND
UART_RTS
UART_RXD
UART_TXD
UART_CTS
CTS
 Software download and upgrade
 Data communication
 AT Command
 GNSS NMEA output
3.6 UART interface
CLM920_TE5 module provides a set of UART interface, the level is 1.8V. This interface
can be used for AT communication and printing log information.
The UART interface supports 4800, 9600, 19200, 38400, 57600, 115200, 230400,
460800 and 921600bps baud rate. The default is 115200bps.
UART interface is defined as follows:
Table 3- 8 UART signal definitions
Pin
Signal name
I/O
Description
11
UART_RX
DI
UART receive data
13
UART_TX
DO
UART transmit data
23
UART_CTS
DI
user allows the module to
transmit
25
UART_RTS
DO
Module requests the user to
send
If need to use the serial port, please refer to the following serial port design.
Figure 3- 12 UART serial port design
The module’s UART port level is 1.8V. A level conversion chip is needed when connect
the port to the MCU whose level is 3.3V. The connection can refer to the following circuit:
UART_CTS
UART_RTS
1uF
VDD_3V3
RX_3V3
TX_3V3
CTS_3V3
RTS_3V3
1uF
VDD_EXT
VCCA
OE
UART_RX
A1
UART_TX
A4
B2
B4
B1
TXB0104
VCCB
A2
A3
B3
Module