2-CH UART To Ethernet Converter, Serial Port Transparent Transmission Module

SKU: 20655
Part Number: 2-CH UART TO ETH
Brand: Waveshare


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2-CH UART to Ethernet Converter, serial port transparent transmission module
2-CH UART TO Ethernet Converter

Serial port transparent transmission

Features at a glance

The 2-CH UART TO ETH provides an easy way to communicate between UART TTL and RJ45 Ethernet, allowing bi-directional transparent data transmission. It is easy to use, along with features like fast data rate, low power consumption, high stability, suits applications such as safety & security, IoT, and so on.

  • Embedded Ethernet MAC and PHY layers
  • Bi-direction transparent data transmission between UART and Ethernet
  • 10/100M, full-duplex/half-duplex auto-negotiation Ethernet interface, 802.3-compliant
  • Auto-MDI/MDIX, detect and switch cable type automatically
  • Supports DHCP auto-obtained IP and DNS domain access
  • Network parameter configuration like chip operating mode, port, IP, via host computer software or UART command
  • 2-CH UART concurrent operation, standalone transparent transmission for each channel
  • Full-duplex or half-duplex UART communication, supports RS485 RX/TX auto switch
  • Supports virtual serial port software (provided)
  • KEEPALIVE mechanism support
  • Comes with development resources and manual (examples for Pico/Raspberry Pi/Arduino/STM32)
Operating voltage 3.3V/5V Operating current 140mA
Operating mode TCP/UDP UART baudrate 300bps ~ 921.6Kbps
UART TTL level 3.3V / 5V compatible Storage temperature -55℃ ~ 125℃
Operating temperature -40℃ ~ 85℃ Dimensions 53.00 × 22.00mm
control interface

supports host boards including Raspberry Pi/Arduino/STM32...

Application example

Bi-direction transparent transmission between UART TTL and wired Ethernet

Extend the communication distance for serial devices

Manage multi serial client devices remotely via one web server

Manage serial server remotely via multi web clients

What's On Board
  1. UART 1 connection status indicator
  2. UART 2 connection status indicator
  3. Power indicator
  4. CH9121 control pins
  1. CH9121 driver
  2. AMS1117-3.3V power supply IC
  3. RT9193-18GB power supply IC
  4. Ethernet port
Pinout definition
5V / 3V3 power positive, use any pin of 5V/3.3V pins for power supply
GND ground
RST1 external reset input, low active
RESET restore to factory setting, detected when chip poweron, low active
TXD1 asynchronous UART 1 data output (enabled by default)
TXD2 asynchronous UART 2 data output (disabled by default)
RXD1 asynchronous UART 1 data input (enabled by default)
RXD2 asynchronous UART 2 data input (disabled by default)
CFG0 UART config mode, low level to enter configuration, high level to exit configuration
RUN Operating status indicating pin
DIR1 UART 1 RS485 RX/TX switch (connects to external RS485 controller)
DIR2 UART 2 RS485 RX/TX switch (connects to external RS485 controller)
Outline Dimensions

*measured manually, for reference only

Resources & Services

* Resources for different product may vary, please check the wiki page to confirm the actually provided resources.

Selection guide
Processor Cortex-M0 Cortex-M4 (up to 120MHz frequency) CH9121
Type RJ45 (10/100Mbps auto-negotiation)
Type UART RS485 RS232+RS485 (allows concurrent operation) UART
Baudrate 600bps~460.8Kbps 600bps~230.4Kbps 300bps ~ 115.2Kbps 600bps~230.4Kbps 300bps~921.6Kbps
Hardware flow NOT supported supported NOT supported
Data bit 5, 6, 7, 8
Stop bit 1, 2
Parity bit None, Even, Odd, Space, Mark
Interface protection
Power supply reverse-proof, ESD protection, anti-surge
Ethernet 1.5KV electromagnetic isolation
RS485 - 2KV ESD protection, 2.2KΩ pull up/down registers 2KV anti-surge 2KV ESD protection, 2.2KΩ pull up/down registers -
Other - - - lightningproof, over-current protection -
Operating mode
Type TCP Server, TCP Client, UDP Server, UDP Client, etc.
TCP Server customizable 1~16 Clients supports 30 Clients supports 2-ch Socket, 8 Clients per ch customizable 1~16 Clients
Features customized heartbeat packets, customized registration packets, customized webpage, RFC2217-like protocol, KeepAlive, timeout auto reboot, short connection, firmware upgrade via network KeepAlive, firmware upgrade via network
- - Modbus gateway, MQTT/JSON to Modbus Modbus gateway, Websocket (webpage to serial) -
Configuration Built-in webpage, Host computer config software, Serial commands Host computer config software, Serial commands
Power supply 3.3V/5V 5~7V 9~24V 5~36V 3.3V/5V
Operating current [email protected] [email protected] TBD [email protected] [email protected]
Operating temp. -25~75℃  -40~85℃ 
Storage temp. -40~105℃  -55℃~125℃

Weight: 0.012 kg

Quick Overview

  1. 2-CH UART TO ETH x1