logger.h File Reference

Modular and flexible logging system for STM32-based MCU projects. More...

#include <stdint.h>
#include <stdarg.h>

Go to the source code of this file.

Enumerations
enum	LogLevel { LOG_LEVEL_ERROR = 0 , LOG_LEVEL_WARN , LOG_LEVEL_INFO , LOG_LEVEL_DEBUG }
	Defines severity levels for logging. More...

Functions
void	Log_Init (void)
	Initialize the logging system.
void	Log_SetLevel (LogLevel level)
	Set the active logging level.
void	Log (LogLevel level, const char *format,...)
	Log a formatted message if the level passes the threshold.
void	Log_Flush (void)
	Flush output buffers.
void	Log_Disable (void)
	Disable all logging at runtime.
	__attribute__ ((weak)) void Log_Write_UART(const char *msg)
	UART output hook. Can be overridden by user.

Detailed Description

Modular and flexible logging system for STM32-based MCU projects.

Features:

• Output to UART, SD card, or both (selectable via #define LOG_USE_* macros).
• Supports blocking and non-blocking UART (DMA or IT).
• Circular ring buffer for non-blocking operation.
• Verbosity control with log levels: ERROR, WARN, INFO, DEBUG.
• Runtime enable/disable of logging via Log_Disable().
• Flush function for SD log file.
• User-overridable hooks for output backends.

Configuration Macros:

• LOG_USE_UART: Enable/disable UART output (default: 1)
• LOG_USE_SD: Enable/disable SD card output (default: 0)
• LOG_USE_IT: Enable interrupt-based UART TX (default: 1)
• LOG_USE_DMA: Enable DMA-based UART TX (default: 0)
• LOG_BUFFER_SIZE: Buffer size for log formatting
• LOG_RING_BUFFER_SIZE: Ring buffer size for non-blocking TX

Example:

Log_Init();
Log_SetLevel(LOG_LEVEL_DEBUG);
Log(LOG_LEVEL_INFO, "System initialized.\n");
Log(LOG_LEVEL_DEBUG, "ADC value: %d\n", adc_value);
Log_Disable();  // Temporarily stop logging
Log(LOG_LEVEL_ERROR, "This won't be printed.\n");
Log_Flush();    // Sync SD card if enabled

Enumeration Type Documentation

LogLevel

enum LogLevel

Defines severity levels for logging.

Enumerator
LOG_LEVEL_ERROR	Critical error
LOG_LEVEL_WARN	Warning but not fatal
LOG_LEVEL_INFO	Informational message
LOG_LEVEL_DEBUG	Debug-level message

Function Documentation

__attribute__()

__attribute__

(

(weak)

)

const

UART output hook. Can be overridden by user.

Default SD card log output (weak). Can be overridden for filters, timestamps, or buffering.

SD card output hook. Can be overridden by user.

Parameters

msg	Null-terminated string to send via UART.
msg	Null-terminated string to write to file.
msg	Null-terminated string to append to log file.

Log()

void Log	(	LogLevel	level,
		const char *	format,
			... )

Log a formatted message if the level passes the threshold.

Parameters

level	The severity of the message.
format	printf-style format string.
...	Arguments to format.

Log a formatted message if the level passes the threshold.

• Message is dropped if below current log level or if logging is disabled.
• Output is routed to UART and/or SD depending on configuration.

Parameters

level	Severity level (LOG_LEVEL_ERROR, etc.)
format	printf-style format string.
...	Arguments to format.

Log_Disable()

void Log_Disable

(

void

)

Disable all logging at runtime.

Logging can be re-enabled by calling Log_SetLevel().

Disable all logging at runtime.

Log_Flush()

void Log_Flush

(

void

)

Flush output buffers.

For SD logging, this calls f_sync() to commit to disk.

Flush output buffers.

Log_Init()

void Log_Init

(

void

)

Initialize the logging system.

Sets up buffers, SD card (if enabled), and clears state.

Initialize the logging system.

• Resets the ring buffer
• Enables logging
• Opens SD file if SD logging is enabled

Log_SetLevel()

void Log_SetLevel

(

LogLevel

level

)

Set the active logging level.

Messages below this level will be ignored.

Parameters

level

One of the values from LogLevel.

Set the active logging level.

Parameters

level

Desired log level (e.g., LOG_LEVEL_DEBUG).