3 releases (breaking)
0.12.0 | Oct 10, 2024 |
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0.10.0 | Jul 15, 2024 |
0.9.1 |
|
0.8.0 |
|
0.2.1 |
|
#98 in Embedded development
18,843 downloads per month
Used in 21 crates
35KB
621 lines
esp-println
A library that provides print!
, println!
, dbg!
implementations and
logging capabilities for Espressif devices.
- Supports all Espressif ESP32 family devices.
- Supports different communication methods:
- UART (Default)
- JTAG-Serial (Only available in ESP32-C3, ESP32-C6, ESP32-H2, ESP32-S3)
- No-op: Turns printing into a no-op
- Supports
defmt
backend
Usage
esp-println = { version = "0.11.0", features = ["esp32c2"] }
or cargo add esp-println --features esp32c2
It's important to specify your target device as feature.
Then in your program:
use esp_println::println;
You can now println!("Hello world")
as usual.
Features
- There is one feature for each supported target:
esp32
,esp32c2
,esp32c3
,esp32c6
,esp32h2
,esp32s2
, andesp32s3
.- One of these features must be enabled.
- Only one of these features can be enabled at a time.
- There is one feature for each supported communication method:
uart
,jtag-serial
andauto
.- Only one of these features can be enabled at a time.
no-op
: Don't print anything.log
: Enables logging usinglog
crate.colors
: Enable colored logging.- Only effective when using the
log
feature.
- Only effective when using the
critical-section
: Enables critical sections.defmt-espflash
: This is intended to be used withespflash
, see-L/--log-format
argument offlash
ormonitor
subcommands ofespflash
andcargo-espflash
. Uses rzCOBS encoding and adds framing.
Default Features
By default, we use the auto
, critial-section
and colors
features.
Which means that it will auto-detect if it needs to print to the UART or JTAG-Serial, use critical sections and output
messages will be colored.
If we want to use a communication method that is not auto
, the default
one, we need to disable the default features.
Logging
With the feature log
activated you can initialize a simple logger like this
init_logger(log::LevelFilter::Info);
There is a default feature colors
which enables colored log output.
Additionally, you can use
init_logger_from_env();
In this case the following environment variables are used:
ESP_LOG
log messages you want to show, similar toRUST_LOG
. RegEx is not supported. e.g.warn,test::foo=info,test::foo::bar=debug
If this simple logger implementation isn't sufficient for your needs, you can implement your own logger on top of esp-println
. See Implementing a Logger section log documentaion
defmt
Using the defmt-espflash
feature, esp-println
will install a defmt
global logger. The logger will
output to the same data stream as println!()
, and adds framing bytes so it can be used even with
other, non-defmt
output. Using the defmt-espflash
feature automatically uses the rzCOBS encoding and does
not allow changing the encoding.
Follow the defmt
book's setup instructions on how to
set up defmt
. Remember, the global logger is already installed for you by esp-println
!
Please note that defmt
does not provide MSRV guarantees with releases, and as such we are not able to make any MSRV guarantees when this feature is enabled. For more information refer to the MSRV section of defmt
's README:
https://github.com/knurling-rs/defmt?tab=readme-ov-file#msrv
Troubleshooting linker errors
If you experience linker errors, make sure you have some reference to esp_println
in your code.
If you don't use esp_println
directly, you'll need to add e.g. use esp_println as _;
to your
import statements. This ensures that the global logger will not be removed by the compiler.
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.
Dependencies
~0.3–1.7MB
~27K SLoC