ESP32 logger

Logging library for ESP-32

Features

• Context-based logging (separate logger may be defined for specific object/task/context)
• Multiple appenders may be used to send log messages to the network, filesystem, UART etc.
• Modular and extensible architecture, custom appenders may be defined easily
• Allows to buffer startup messages until appender's medium is ready to accept them
• Allows to queue messages and process them in a dedicated thread to minimize impact of slow appenders and ensure thread safety
• Allows to forward ESP32-specific log output to the registered appenders
• Allows to hook log_X output (used in Arduino libs) and forward it to registered appenders

Usage - simple

#include <SPIFFS.h>
#include <logging.hpp>
#include <fs-appender.hpp>
#include <ets-appender.hpp>
#include <udp-appender.hpp>

using namespace esp32m;

void setup()
{
  SPIFFS.begin(true);
  // send log messages to file "mylog" on the SPIFFS
  Logging::addAppender(new FSAppender(SPIFFS, "/mylog"));
  // send log messages to standard output (Serial)
  Logging::addAppender(&ETSAppender::instance());
  // send log messages to 192.168.1.1:1234 in the form of UDP packets
  Logging::addAppender(new UDPAppender("192.168.1.1", 1234));
  // redirect standard output to appenders
  Logging::hookUartLogger();
  // now use log_X macros to forward log messages to the registered appenders
  log_i("hello world!");
}

void loop() {
  ...
}

log_x() macros (where x is e,w,i,d or v) in the above example is defined in the Arduino and if you use the example as is, log messages will go through Arduino logging subsystem. It is possible to bypass Arduino and log directly to appenders simply by adding the

build_flags =
    -DLOGGING_REDEFINE_LOG_X

to the platformio.ini.

Usage - advanced

#include <Arduino.h>

#include <logging.hpp>
#include <ets-appender.hpp>
#include <udp-appender.hpp>

using namespace esp32m;

class C1 : public SimpleLoggable
{
public:
  C1() : SimpleLoggable("c1") {}
  void doWork()
  {
    // will log messages in the context of the "c1" class
    logI("doing work");
  }
};

C1 c1;

void setup()
{
  // send log messages to standard output (Serial)
  Logging::addAppender(&ETSAppender::instance());
  // send log messages to 192.168.1.1:1234 in the form of UDP packets
  Logging::addAppender(new UDPAppender("192.168.1.1", 1234));
  // redirect standard output to appenders
  Logging::hookUartLogger();
}

void loop()
{
  c1.doWork();
  delay(1000);
}