w5100-rs/README.md

W5100 Driver

Fork status:

• Work-in-progress fork of the crate w5500 for W5100. The two chips are different versions of the same design, very similar but not fully compatible. The older revision of the Arduino Ethernet Shield uses W5100, hence the need for this fork.
• What works: receive and send UDP packets.
• Tested on Arduino Uno with Arduino Ethernet Shield.

This crate is a driver for the WIZnet W5500 chip. The W5500 chip is a hardwired TCP/IP embedded Ethernet controller that enables embedded systems using SPI (Serial Peripheral Interface) to access the LAN. It is one of the more popular ethernet modules on Arduino platforms.

Embedded-HAL

The embedded-hal is a standard set of traits meant to permit communication between MCU implementations and hardware drivers like this one. Any microcontroller that implements the spi::SpiDevice or spi::SpiBus can use this driver.

Example Usage

Below is a basic example of sending UDP packets to a remote host. An important thing to confirm is the configuration of the SPI implementation. It must be set up to work as the W5500 chip requires. That configuration is as follows:

• Data Order: Most significant bit first
• Clock Polarity: Idle low
• Clock Phase: Sample leading edge
• Clock speed: 33MHz maximum

use core::net::{IpAddr, Ipv4Addr, SocketAddr};
#
# struct Mock;
#
# impl embedded_hal::spi::ErrorType for Mock {
#     type Error = core::convert::Infallible;
# }
#
# impl embedded_hal::spi::SpiDevice for Mock {
#     fn transaction(&mut self, operations: &mut [embedded_hal::spi::Operation<'_, u8>]) -> Result<(), Self::Error> {
#         Ok(())
#     }
# }
use embedded_nal::UdpClientStack;

let mut spi = Mock;

let mut device = w5500::UninitializedDevice::new(w5500::bus::FourWire::new(spi))
    .initialize_manual(
        w5500::MacAddress::new(0, 1, 2, 3, 4, 5),
        Ipv4Addr::new(192, 168, 86, 79),
        w5500::Mode::default()
    ).unwrap();

// Allocate a UDP socket to send data with
let mut socket = device.socket().unwrap();

// Connect the socket to the IP address and port we want to send to.
device.connect(&mut socket,
    SocketAddr::new(IpAddr::V4(Ipv4Addr::new(192, 168, 86, 38)), 8000),
).unwrap();

// Send the data
nb::block!(device.send(&mut socket, &[104, 101, 108, 108, 111, 10]));

// Optionally close the socket
device.close(socket);

Todo

In no particular order, things to do to improve this driver.

• Add support for TCP server implementations
• Add support for DHCP

License

Support me via LiberaPay

Based on w5500 licensed under MIT/Apache, see Git history for the list of contributors.

GNU AGPL v3, CopyLeft 2025 Pascal Engélibert (why copyleft?)

This program is free software: you can redistribute it and/or modify it under the terms of the GNU Affero General Public License as published by the Free Software Foundation, version 3 of the License.
This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Affero General Public License for more details.
You should have received a copy of the GNU Affero General Public License along with this program. If not, see https://www.gnu.org/licenses/.