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Flipper Zero Ethernet Test Module — Complete Guide

One-liner: the Ethernet test module plugs a 10/100 Ethernet port onto your Flipper Zero — a WIZnet W5500 with a built-in TCP/IP stack — turning the Flipper into a pocket LAN tester for cable checks, DHCP validation and ping tests.

Specs at a glance

ItemSpecification
ControllerWIZnet W5500 (hardwired TCP/IP stack)
Ethernet10/100 Mbps with embedded MAC + PHY, auto-negotiation (full/half duplex)
ProtocolsTCP, UDP, ICMP, IPv4, ARP, IGMP, PPPoE; Wake-on-LAN over UDP
Sockets8 independent
Buffer32 KB internal TX/RX memory
InterfaceSPI (up to 80 MHz)
Voltage3.3 V operation, 5 V-tolerant I/O
ConnectorRJ45 with link/activity LEDs
PowerFrom the Flipper GPIO (3.3 V / OTG)

What you can do with it

For a university networking lab this is gold: verify a wall jack before you complain to IT, prove a cable is bad in seconds, and demonstrate DHCP behavior on a real network — all from your pocket.

Wiring to the Flipper

Typical W5500 module (W5500 Lite) wiring:

W5500 moduleFlipper GPIO (pin)
MOSI (MO)A7 (pin 2)
SCLK (SCK)B3 (pin 5)
CS (nSS)A4 (pin 4)
MISO (MI)A6 (pin 3)
RESET (RST)C3 (pin 7)
3V3 (VCC)3V3 (pin 9)
GND (G)GND (pin 8 or 11)

Ready-made "W5500 Ethernet module for Flipper Zero" boards (RJ45 + breakouts) are available; they still expose the same SPI signals — double-check the silkscreen against the table above.

Setup

1. Install the app

The Ethernet apps run on stock and custom firmware alike. Install via:

  • Web catalog (browser + WebUSB): open the Flipper app catalog in a Chromium browser, connect the Flipper, click install. Search for "W5500" or "Ethernet".
  • Mobile app: Flipper mobile app → app catalog → GPIO → W5500 Ethernet.

2. Connect everything

  1. Wire the module to the Flipper GPIO per the table above.
  2. Plug an Ethernet cable into the module's RJ45.
  3. Plug the other end into a switch/router/PC port.

3. First test

  1. Launch the Ethernet app (Apps → GPIO).
  2. Check the header: LAN [UP 100M FD] means the link is established.
  3. Press DHCP — the app requests an address and displays:
IP: 192.168.1.162
MASK: 255.255.255.0
GW: 192.168.1.1
  1. Press Ping and target the gateway (or 8.8.8.8): replies with latency confirm end-to-end connectivity.

Troubleshooting

ProblemCauseFix
No link lightBad cable / port / wiringTry another cable and port; re-check SPI wiring (CS + RESET especially)
LAN [DOWN]Module not initializedConfirm 3V3 and GND; re-run the app; reboot Flipper
DHCP times outNetwork has no DHCP / cable faultCheck the link first; try a static IP; test cable elsewhere
App missingNot installedInstall via web or mobile app catalog
Only 10 MbpsAuto-negotiation quirk on some switchesTry a different switch port; the module is 10/100 by design

More help: the SDRLAB troubleshooting hub.