CLM920_NC2_LTE M.2 Module Hardware Usage Guide
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Table 3-6 UART serial port signal definition
Pin number
Signal name
IO
description
35
UART_TXD
DO
send data
37
UART_RXD
DI
Receive data
If you need to use the serial port, you need to refer to the following serial port design.
Figure 3-8 UART serial port design
The serial port level of the module is 1.8V. If the serial port needs to be connected to the
MCU of 3.3V level, it is necessary to add a level conversion chip externally to achieve level
matching. For the chip connection method, refer to the following circuit:
Figure 3-9 Level shifting circuit
