Quelltext der Seite WSAL20410 – Pico-ETH-CH9121/en

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'''Documentation notice:''' This technical documentation was independently rewritten from an archived supplier source. Check technical details and commands against the product version and manufacturer documentation before use.

== Summary ==
The Pico-ETH-CH9121 is a converter that enables serial communication over the network. It uses the CH9121 chip and provides two independent UART channels with configurable network operating modes (TCP/UDP). The module connects via a standard Pico header and can be configured via software or serial commands.

== Related products at JW Tech ==
* [https://shop.jw-tech.eu/p/WSAL20410 WSAL20410 – Ethernet to UART Converter for Raspberry Pi Pico, 10/100M Ethernet]

== Technical overview ==
* Two independent UART channels with transparent transmission between UART and Ethernet.
* Four operating modes: TCP Client, TCP Server, UDP Client, UDP Server.
* By default, UART 2 is disabled; UART 1 operates in TCP Client mode.
* Default values: IP 192.168.1.200, target IP 192.168.1.100, device port 2000, target port 1000, baud rate 9600, 8 data bits, 1 stop bit, no parity.
* Power supplied via VSYS input (3.3 V / 5 V); operating temperature range -40 °C to 85 °C.
* Automatic MDI/MDIX detection and auto-negotiation (10/100 Mbps, full/half duplex).
* Configuration via NetModuleConfig.exe on the host PC or via serial commands.
* Pin mapping: RXD1→GP0, TXD1→GP1, RXD2→GP4, TXD2→GP5, CFG0→GP14, RST1→GP17.

'''Commands and examples – verify before use:''' 
<syntaxhighlight lang="text">
sudo apt-get install p7zip-full
sudo wget https://files.waveshare.com/upload/5/5a/Pico_ETH_CH9121_CODE.7z
7z x Pico_ETH_CH9121_CODE.7z -o./Pico_ETH_CH9121_CODE
cmake -DPICO_BOARD=pico -DPICO_PLATFORM=rp2040 ..
make -j9
cp main.uf2 /media/pi/RPI-RP2/
</syntaxhighlight>

== Notes and version constraints ==
* The exact Pico SDK version and path variables must be adapted to the local environment.
* When flashing, the BOOTSEL button must be held while connecting the USB cable.
* To use a screen, the mini jumper on CFG0 must be removed.
* To restore factory settings, short the RESET pads and power-cycle the module.
* The complete list of AT commands is not fully included in the source text; it must be referenced from the datasheet.

== Source and revision record ==
* [https://www.waveshare.com/wiki/Pico-ETH-CH9121 Pico-ETH-CH9121 - Waveshare Wiki]
* Source revision: 102649
* Captured: 2026-09-02T03:47:53+00:00
* SHA-256: <code>876590522d2c0ffec0fd0a86c0bc81c2d02d2aacabecdcb5ce8ca5dc4eda8c16</code>