Lib.rs

› esp-println › Features

Cargo Features

[dependencies]
esp-println = { version = "0.16.1", default-features = false, features = ["esp32", "esp32c2", "esp32c3", "esp32c6", "esp32h2", "esp32s2", "esp32s3", "critical-section", "timestamp", "auto", "jtag-serial", "uart", "no-op", "log-04", "defmt-espflash", "colors"] }
default = auto, colors, critical-section

These default features are set whenever esp-println is added without default-features = false somewhere in the dependency tree.

esp32

Enables esp32 of esp-metadata-generated and optional esp-sync

esp-sync:

Unstable dependencies that are not (strictly) part of the public API

esp32c2

Enables esp32c2 of esp-metadata-generated and optional esp-sync

esp32c3

Enables esp32c3 of esp-metadata-generated and optional esp-sync

esp32c6

Enables esp32c6 of esp-metadata-generated and optional esp-sync

esp32h2

Enables esp32h2 of esp-metadata-generated and optional esp-sync

esp32s2

Enables esp32s2 of esp-metadata-generated and optional esp-sync

esp32s3

Enables esp32s3 of esp-metadata-generated and optional esp-sync

critical-section default

Use a critical section around print calls. This ensures that the output is consistent.

Enables esp-sync

timestamp

Prints the timestamp in the log message.

This option requires the following function to be implemented:

extern "Rust" {
    fn _esp_println_timestamp() -> u64;
}

This function should return the current timestamp in milliseconds since power on. When using esp_hal, you can define this function as follows:

#[unsafe(no_mangle)]
pub extern "Rust" fn _esp_println_timestamp() -> u64 {
    esp_hal::time::Instant::now()
        .duration_since_epoch()
        .as_millis()
}
auto default

Output interfaces

You must enable exactly 1 of the below features to enable to intended communication method.

Note: some boards, such as Waveshare's ESP32-C6-DEV-KIT-N8, come with a USB hub. This can confuse the auto feature. If you experience no log output, try selecting an output interface instead of relying on auto.

Automatically select the best output interface for the target.

Enables portable-atomic

Optional dependencies

jtag-serial

Use the USB_SERIAL_JTAG interface for printing. Available on ESP32-C3, ESP32-C6, ESP32-H2, ESP32-P4, and ESP32-S3.

Enables portable-atomic

uart

Use the UART0 peripheral for printing. Available on all devices.

no-op

Don't print anything

log-04

Logging framework features

Enables using the log crate for logging.

Enables log

Affects esp-println::logger…

defmt-espflash

Enables printing using defmt.

defmt-encoded output can only be read using espflash. With esp_hal, this works out of the box. Without esp_hal, you need to set the --log-format defmt argument for espflash.

Enables encoding-rzcobs of defmt

Logging interfaces, they are mutually exclusive so they need to be behind separate features.

Affects esp-println::defmt…

colors default

log-specific features

Colors the message severity in the terminal.