Soldered NULA Ethernet W55RP20

Add wired Ethernet to your project without a separate network chip or a heavy software stack. The Soldered NULA Ethernet W55RP20 is built around WIZnet's W55RP20, a single package that fuses the dual-core RP2040 with the W5500 hardwired TCP/IP controller and a 10/100 Ethernet PHY. You get the familiar RP2040 development experience and a full hardware TCP/IP stack on the same chip, so networking runs in silicon instead of eating your CPU time. Perfect for industrial sensors, building automation, data loggers, and any device that needs a reliable wired connection.

The board breaks the W55RP20 out along both long edges. The left side carries an 8-pin and a 10-pin header with power rails and most of the chip's GPIO; the right side adds a further 8-pin and 6-pin header. A separate 3-pin header exposes SWD for debugging. An RJ45 jack with integrated magnetics handles the Ethernet side, with two status LEDs built into the connector. A Qwiic connector gives you tool-free I2C expansion, a microSD slot (SPI) covers data logging and storage, and an onboard TP4056M charger with a JST connector lets you run and charge a Li-ion/Li-po battery. Power and programming come over USB-C.

If you know the Raspberry Pi Pico or any RP2040 board, you already know how to program this one. It works with the Arduino IDE, MicroPython, and C/C++, and existing RP2040 code, libraries, and examples run with minimal changes. A USB-A to USB-C cable is included in the package, so you can start programming right out of the box.

Note:

• The W55RP20 does NOT support auto-MDIX. Use a straight-through cable to a switch or router, and a crossover cable to another W55RP20, a server, or a workstation.
• GPIO logic is 3.3 V and NOT 5 V tolerant.
• Before connecting a 3.7 V Li-ion battery, please refer to the detailed technical documentation which you can find in the links below.

• SoC: WIZnet W55RP20 (RP2040 + W5500 in one 8 × 8 mm QFN-68)
• CPU: Dual-core ARM Cortex-M0+ @ 133 MHz
• Memory: 264 KB SRAM, 2 MB Flash, 16 KB ROM
• Ethernet: W5500 hardwired TCP/IP (TCP, UDP, IPv4, ICMP, ARP, IGMP, PPPoE), 10/100 Mbps, integrated PHY, 8 sockets, 32 KB TX/RX buffer
• Ethernet Connector: RJ45 with integrated magnetics and status LEDs
• GPIO: 23 GPIO, labeled IO0-IO29 on the silkscreen (IO17 and IO20-IO25 are used internally by the W55RP20 and not exposed)
• GPIO Breakout: Left side 8-pin + 10-pin, right side 8-pin + 6-pin
• Debug: 3-pin SWD header (SWD, GND, CLK)
• Peripherals: 2x UART, 4x SPI, 3x I2C, 16x PWM, 2× PIO blocks (8 state machines), 12× DMA
• ADC: 12-bit (0 - 3.3 V range)
• MicroSD Reader: Onboard slot wired, with card power control and card-detect
• Qwiic Port: Tool-free I2C expansion
• Battery Support: JST connector with onboard TP4056M Li-Ion/Li-Po charger and charge status LED (3.7 V)
• USB-C: Power (5 V), programming, and serial communication
• User Interface: WS2812 RGB LED, power LED, Ethernet status LEDs, RESET, BOOT, and USER buttons
• Logic Level: 3V3 GPIO - NOT 5V tolerant!
• Development Support: Arduino IDE, MicroPython, C/C++
• Mounting: 4 × 3.2 mm holes (M3), LEGO-compatible
• Dimensions: 68.6 × 58.4 mm (2.70 × 2.30 in)
• Hardware Design: Open-source, made in EU