imxrt-uart-log

Log data over a serial interface. There are two logging implementations for NXP's i.MX RT processors:

• a simple, blocking logger. Useful for basic logging throughout the software stack, including interrupt, fault, and panic handlers.
• a DMA-based, non-blocking interface. Useful for logging that needs to happen quickly in thread mode. Uses a default buffer, with an option for a user-supplied DMA buffer.

Built on the [imxrt-hal] hardware abstraction layer for i.MX RT processors, version 0.3. Compatible with [log] version 0.4.

See the documentation for recommended use-cases, implementation descriptions, and examples:

cargo doc --open

i.MX RT Compatibility

This crate supports all of the same i.MX RT variants as the [imxrt-hal] crate. To see the supported i.MX RT variants, check the HAL's feature support list.

:information_source: As of this writing, the HAL only supports one i.MX RT variant, the "imxrt1062". For convenience, the "imxrt1062" feature is this crate's default feature. This default feature may change in future releases.

Performance

The table below describes the execution time for logging statements on a Teensy 4. For more information on the test setup, consult the crate documentation. See the two examples to reproduce the test.

| Logging Invocation | Execution Time, Blocking (us) | Execution Time, DMA (us) | | ----------------------------------------------------- | ----------------------------- | ------------------------ | | log::info!("Hello world! 3 + 2 = {}", 3 + 2); | 3120 | 3.16 | | log::info!("Hello world! 3 + 2 = 5"); | 3120 | 2.84 | | log::info!(""); | 1220 | 2.36 | | log::info!(/* 100 character string */); | 9880 | 4.12 |

Testing

The crate's examples run on hardware. See the documentation at the top of each example for more information.

For examples that run on a Teensy 4, you'll need the build dependencies described in the teensy4-rs project.

Use make to build an example:

make t4_blocking

When building an example for the Teensy 4, the build will print the location of the *.hex file. You may download the file to a Teensy using either the Teensy Loader Application or the teensy_loader_cli command-line Teensy loader.

To run this crate's unit tests, and to check documentation examples, use make test.

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.

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.