#defmt #log #logging #back-end #log-messages

no-std log-to-defmt

A backend for log that emits through defmt

1 unstable release

0.1.0 Jan 2, 2023

#21 in #defmt

Download history 22/week @ 2024-02-22 22/week @ 2024-02-29 16/week @ 2024-03-07 12/week @ 2024-03-14 4/week @ 2024-03-21 19/week @ 2024-03-28 24/week @ 2024-04-04 5/week @ 2024-04-11 2/week @ 2024-04-18 3/week @ 2024-05-16 13/week @ 2024-05-23 25/week @ 2024-05-30 14/week @ 2024-06-06

55 downloads per month




This is a logging adapter that acts as an implementation of the log crate and hands the rendered messages off to the defmt crate.

Using this is generally not recommended: Once the log infrastructure is pulled into a project, Rust's string formatting is brought in, avoiding which is a big part of the point of defmt.

However, this can be useful during development, when debugging a particular library (that optionally produces messages through log) on a platform for which a defmt output has already been established.


The current implementation of this takes a huge amount of shortcuts: not only does it not convert log levels, it also hardwires some to the most verbose level, discards lots of information that would otherwise be available, and uses a fixed size buffer.

Future iterations of this crate are expected to address these on demand; for example, this could gain a build time configuration mechanism for the maximum expected length, or an alloc feature that renders the log messages to a Vec instead of a heapless::Vec before handing them off to defmt as a slice.

The crate will likely introduce such features (altering its behavior) without declaring breaking changes; users are advised to configure their error levels to match which messages they expect to see.

License: MIT OR Apache-2.0


~38K SLoC