This repository demonstrates how to use RP2040 with W5500 Ethernet module, to implement networking. In this example, a very simple HTTP server is implemented. See other examples for more functionality.

RP2040 Pico wiring

The W5500 module uses SPI for communication. The following pins are used by this example (modify main.c if you use a different pinout):

enum { LED = 25, SPI_CS = 17, SPI_CLK = 18, SPI_TX = 19, SPI_RX = 16 };

On a breadboard, it might look like this:

Pinout reference

Build and run

Clone Mongoose repo, go to this example, and build it:

git clone https://github.com/cesanta/mongoose
cd mongoose/examples/ro2040/pico-w5500
make

The above will make a firmware in build/example.uf2. Reboot your Pico board in bootloader mode, and copy example.uf2 to the RPI disk.

Attach serial console. Then, plug in Ethernet cable:

$ cu -l /dev/cu.usb* -s 115200
4653 2 main.c:79:main                   Ethernet: down
520b 2 main.c:79:main                   Ethernet: down
5dc3 2 main.c:79:main                   Ethernet: down
6593 1 mongoose.c:6757:onstatechange    Link up
659a 3 mongoose.c:6840:tx_dhcp_discover DHCP discover sent
667b 3 mongoose.c:6723:arp_cache_add    ARP cache: added 192.168.0.1 @ 90:5c:44:55:19:8b
667d 2 mongoose.c:6749:onstatechange    READY, IP: 192.168.0.24
667e 2 mongoose.c:6750:onstatechange           GW: 192.168.0.1
6680 2 mongoose.c:6752:onstatechange           Lease: 86062 sec
697b 2 main.c:79:main                   Ethernet: up
7533 2 main.c:79:main                   Ethernet: up

Note the aquired IP address printed. Run a browser, and type that IP address in the address field. You should see an "ok" message in a browser: