esp-wifi

A WiFi, BLE and ESP-NOW driver for Espressif microcontrollers.

Current support

If a cell contains an em dash (—) this means that the particular feature is not present for a chip. A check mark (✓) means that some driver implementation exists. A Tilde (˜) means it is implemented but buggy. An empty cell means that the feature is present in the chip but not implemented yet.

Minimum supported Rust compiler version: 1.72.0.0

Usage

Importing

Ensure that the right features are enabled for your chip. See Examples for more examples.

[dependencies.esp-wifi]
# A supported chip needs to be specified, as well as specific use-case features
features = ["esp32s3", "wifi", "esp-now"]

Link configuration

Make sure to include the rom functions for your target:

# .cargo/config.toml
rustflags = [
    "-C", "link-arg=-Tlinkall.x",
    "-C", "link-arg=-Trom_functions.x",
]

At the time of writing, you will already have the linkall flag if you used cargo generate. Generating from a template does not include the rom_functions flag.

Optimization Level

It is necessary to build with optimization level 2 or 3 since otherwise, it might not even be able to connect or advertise.

To make it work also for your debug builds add this to your Cargo.toml

[profile.dev.package.esp-wifi]
opt-level = 3

Xtensa considerations

Within this crate, CCOMPARE0 CPU timer is used for timing, ensure that in your application you are not using this CPU timer.

USB-SERIAL-JTAG

When using USB-SERIAL-JTAG (for example by selecting jtag-serial in esp-println) you have to activate the feature phy-enable-usb.

Don't use this feature if you are not using USB-SERIAL-JTAG as it might reduce WiFi performance.

Features

Note that not all features are available on every MCU. For example, ble (and thus, coex) is not available on ESP32-S2.

When using the dump-packets feature you can use the extcap in extras/esp-wifishark to analyze the frames in Wireshark. For more information see extras/esp-wifishark/README.md

Tuning

The defaults used by esp-wifi and the examples are rather conservative. It is possible to change a few of the important settings.

See Tuning for details

Examples

See Examples for details.

Missing / To be done

• Support for non-open SoftAP

Directory Structure

• src/timer/: systimer code used for timing and task switching
• src/preemt/: a bare minimum RISCV and Xtensa round-robin task scheduler
• src/compat/: code needed to emulate enough of an (RT)OS to use the driver
  • common.rs: basics like semaphores and recursive mutexes
  • timer_compat.rs: code to emulate timer related functionality
• examples/*.rs: examples

Driver version

This uses the WiFi drivers from https://github.com/esp-rs/esp-wireless-drivers-3rdparty

v5.1.2-602-gdb1e54a0c5-dirty commit db1e54a0c537d8b2cc2bd109ee88b50e1ca0ea80

https://github.com/esp-rs/esp-wireless-drivers-3rdparty/ (commit ca2809144cf6d2f89d413f1d415f1c4454ee6249)

License

Licensed under either of:

• Apache License, Version 2.0 (LICENSE-APACHE or http://www.apache.org/licenses/LICENSE-2.0)
• MIT license (LICENSE-MIT or http://opensource.org/licenses/MIT)

at your option.

Contribution

Unless you explicitly state otherwise, any contribution intentionally submitted for inclusion in the work by you, as defined in the Apache-2.0 license, shall be dual licensed as above, without any additional terms or conditions.