Logger Library for Embedded Systems such as Arduino

Logger provides simple logging (Print output macros, defaulting to Serial) with:

• LOG
• LOGln
• LOGI (Info)
• LOGW (Warning)
• LOGE (Error)
• LOGD (Debug, only if #def DEBUG)
• LOGIS, LOGIC, LOGIE

functions.

The formatter supports standard printf specifiers such as %d, %ld, %u, %x, %f, %c, %s, and %p. The custom %b specifier prints the low 8 bits of the supplied value as a binary string.

In your main program you set the level with:

logSetLevel(LOG_LEVEL_DEBUG);

or any of the following LOG_LEVEL_INFO, LOG_LEVEL_WARN, LOG_LEVEL_ERROR, LOG_LEVEL_NONE and then you can log with the LOG functions.

If the current level is INFO, WARNING and ERROR messages will also be printed. If it is level NONE, no logging will occur. The LOG_LEVEL_* macro values match NimBLE/Mynewt (DEBUG is 0, NONE is 5) to avoid redefinition warnings when both libraries are used. Use the named constants rather than raw numbers.

LOG and LOGln omit [LOG LEVEL] in the output, and it will occur regardless of the current log level.

Existing sketches that assign currentLogLevel directly continue to work, but logSetLevel() is the preferred API for new code.

By default logs are written to Serial. To write to another Arduino Print implementation, such as BLESerial, set the output once:

logSetOutput(bleSerial);
LOGI("Logging over BLE");

Libraries that already manage a va_list can format a leveled line directly to any Print, without reading or changing the global output, using logVPrintLevellnTo().

In your program if you set

#define DEBUG

LOGD will be compiled into the program and if its not set it will be omitted. This will reduce the overhead once only INFO, WARNING or ERROR logging is wanted.

If you use the Arduino Audio library and want to avoid conflicts with its LOGE, LOGI, LOGW, and related macros, define

#define USE_AUDIO_LOGGING

before including logger.h. In that mode LOG, LOGln, logPrint, and logPrintln remain available, but the level macros, level constants, currentLogLevel, logSetLevel(), and logGetLevel() are not declared by this library.

Implementation

The library uses compact macros as log-level gates. This avoids formatting the log text when the log level is not met.

For portability, it implements its own printf-style formatting and includes a %b formatter. If code size is more important than %b support, define

#define LOGGER_USE_SIMPLE_VSNPRINTF

before including logger.h to use the platform vsnprintf() formatter directly.

Installation

url=https://github.com/uutzinger/logger or use the Arduino library manager.

Example Use

/////////////////////////////////////////////////////////////////////////////////////////
// Example Program using Logger
/////////////////////////////////////////////////////////////////////////////////////////

#include <Arduino.h>
#include <logger.h>

/////////////////////////////////////////////////////////////////////////////////////////
// Select the  default log level, you can change this at runtime also
// #define LOG_LEVEL LOG_LEVEL_NONE 
// #define LOG_LEVEL LOG_LEVEL_ERROR
// #define LOG_LEVEL LOG_LEVEL_WARN 
#define LOG_LEVEL LOG_LEVEL_INFO 
// #define LOG_LEVEL LOG_LEVEL_DEBUG
//
#define BAUDRATE 500000 // Up to 2,000,000 on ESP32, however more than 500 kBaud might be unreliable
/////////////////////////////////////////////////////////////////////////////////////////

...

void setup()
{
  logSetLevel(LOG_LEVEL);

  Serial.begin(BAUDRATE);
  while ( !Serial ){ delay(100); }

  // Optional: route logs to any Print target instead of Serial.
  // logSetOutput(bleSerial);

  LOGI("mySensor");
  ...

  LOGI("Reading AFE Info");
  while (!mySensor.readInfo()){
    LOGE("Sensor: failed to read ID, please make sure all the pins are connected");
    delay(1000);
  }

  LOGI("Initializing  ...");
  mySensor.begin();
}

void loop() {
    data = mySensor.get ...;    
    LOGln("Data: %ld", data);
}

Dependencies

None

Contributing

OpenAI Codex

License

See LICENSE.