The note-c C library for communicating with the Blues Wireless Notecard via serial or I²C.
This library allows you to control a Notecard by writing a C or C++ program. Your program may programmatically configure Notecard and send Notes to Notehub.io.
This library is used by the note-arduino library, which includes it as a git subtree.
The API documentation for this library can be found here.
note-c provides a comprehensive and flexible logging functionality.
To activate logging, you must provide a callback for logging via
hookDebugOutput(). The callback takes the following form:
typedef size_t (*debugOutputFn) (const char *text);The callback is responsible for taking a character array (C-style string) and returning the number of bytes processed (written out) as confirmation. The exact implementation will be up to the user who provided the function pointer, but its presence will active logging in the library.
note-c provides for four (4) levels of logging. Here they are listed from
most severe to most verbose:
NOTE_C_LOG_LEVEL_ERRORNOTE_C_LOG_LEVEL_WARNNOTE_C_LOG_LEVEL_INFONOTE_C_LOG_LEVEL_DEBUG
By default, note-c logs at NOTE_C_LOG_LEVEL_INFO.
To modify the default behavior, you may specify the desired log level at compile time, as follows:
-DNOTE_C_LOG_LEVEL=0NOTE: In the example above, you will notice we used zero (0), instead of
NOTE_C_LOG_LEVEL_ERROR. This is because the warning constants are internal to
the library, and not available in the context of the command line.
Here, we have decided to show only the most severe (i.e. [ERROR]) logs.
Alternatively, you may set the level to any of the values listed above.
In the previous section, we discussed setting the base (or default) logging
behavior for the library. However, you may also set the log level dynamically,
during runtime, by using the NoteSetLogLevel() API.
NoteSetLogLevel(NOTE_C_LOG_LEVEL_WARN);Tangential to the standard logging behavior, note-c also provides a helper
function to invoke/extract synchronization logs from the Notecard.
NoteDebugSyncStatus()
Instead of toggling features inside the library, this helper functions sends a request to the Notecard to inquire about its synchronization status and logs those details.
The function is designed to be called in a loop and throttled by a parameter. See the documentation page for more information.
The note-c versioning scheme is a variant of Semantic
Versioning.
Below is a high-level overview of the major/minor/patch versions:
- Major Version: Signals incompatible API changes.
- Minor Version: Signals added functionality in a backward compatible manner.
- Patch Version: Signals backward compatible bug fixes.
Beyond the SemVer foundation, Blues has imposed additional requirements for a version to be considered valid:
- Major/minor/patch versions SHALL NOT be zero.
- For anything other than major version, version numbers MUST NOT contain
EITHER leading zeroes OR trailing zeroes (e.g. version
1.10.2is invalid).
Example version progression:
1.8.1,1.9.1,1.9.2,1.11.1,1.11.2,1.11.3,1.12.1,2.1.1
These additional constraints have been observed to help disambiguate versions and reduce support burden.
The version can be referenced/tested programmatically via the following
preprocessor defined integers found in note.h:
NOTE_C_VERSION_MAJORNOTE_C_VERSION_MINORNOTE_C_VERSION_PATCH
The version may also be logged via the preprocessor defined string literal,
NOTE_C_VERSION.
We love issues, fixes, and pull requests from everyone. By participating in this project, you agree to abide by the Blues Inc code of conduct.
For details on contributions we accept and the process for contributing, see our contribution guide.
For additional Notecard SDKs and Libraries, see:
- note-arduino for Arduino support
- note-python for Python
- note-go for Go
Copyright (c) 2019 Blues Inc. Released under the MIT license. See LICENSE for details.