Add live Debug Level switching

Listen to the same serial port used for debug output to switch Debug Level.

Enter V,D,I,W,E or VERBOSE, DEBUG, INFO, WARNING, or ERROR terminated by
a new line/Line feed ('\n) character. CRLF ('\r\n') works as well.

NOTE: Check your serial monitor or terminal settings is configured to send a line ending of new line/Line feed ('\n' or '\r\n') at the end of the string.

src/Arduino_DebugUtils.cpp

@@ -21,6 +21,13 @@
 
 #include "Arduino_DebugUtils.h"
 
+/******************************************************************************
+   INPUT BUFFER
+ ******************************************************************************/
+
+#define COMMAND_BUFFER_SIZE 50  // Define a reasonable size for the input buffer
+char commandBuffer[COMMAND_BUFFER_SIZE];
+
 /******************************************************************************
    CONSTANTS
  ******************************************************************************/
@@ -54,7 +61,7 @@ int Arduino_DebugUtils::getDebugLevel() const {
 }
 
 void Arduino_DebugUtils::setDebugOutputStream(Stream * stream) {
-  _debug_output_stream = stream;
+  _debug_io_stream = stream;
 }
 
 void Arduino_DebugUtils::newlineOn() {
@@ -125,6 +132,65 @@ void Arduino_DebugUtils::print(int const debug_level, const __FlashStringHelper
   va_end(args);
 }
 
+void Arduino_DebugUtils::processDebugUpdateLevelCommand() 
+{
+  static size_t bufferIndex = 0;  // Index to track buffer position
+
+  // Check if the stream is available and has data
+  if (_debug_io_stream && _debug_io_stream->available()) {
+    // Read each character from the stream
+    char incomingChar = _debug_io_stream->read();
+
+    // If it's a newline character, process the command
+    if (incomingChar == '\n') {
+      commandBuffer[bufferIndex] = '\0';  // Null-terminate the string
+
+      // Compare C-strings for each command
+      if (strcmp(commandBuffer, "V") == 0 || strcmp(commandBuffer, "VERBOSE") == 0)
+      {
+        setDebugLevel(DBG_VERBOSE);
+        _debug_io_stream->println("Debug level set to VERBOSE.");
+      }
+      else if (strcmp(commandBuffer, "D") == 0 || strcmp(commandBuffer, "DEBUG") == 0)
+      {
+        setDebugLevel(DBG_INFO);
+        _debug_io_stream->println("Debug level set to DEBUG.");
+      }
+      else if (strcmp(commandBuffer, "I") == 0 || strcmp(commandBuffer, "INFO") == 0)
+      {
+        setDebugLevel(DBG_INFO);
+        _debug_io_stream->println("Debug level set to INFO.");
+      }
+      else if (strcmp(commandBuffer, "W") == 0 || strcmp(commandBuffer, "WARNING") == 0)
+      {
+        setDebugLevel(DBG_WARNING);
+        _debug_io_stream->println("Debug level set to WARNING.");
+      }
+      else if (strcmp(commandBuffer, "E") == 0 || strcmp(commandBuffer, "ERROR") == 0)
+      {
+        setDebugLevel(DBG_ERROR);
+        _debug_io_stream->println("Debug level set to ERROR.");
+      }
+      else
+      {
+        _debug_io_stream->println("Invalid command. Use V,D,I,W,E or VERBOSE, DEBUG, INFO, WARNING, or ERROR.");
+      }
+
+      // Clear the buffer for the next command
+      bufferIndex = 0;
+      commandBuffer[0] = '\0';
+    }
+    else if (incomingChar != '\r')
+    {
+      // Add the character to the buffer if it's not a carriage return
+      if (bufferIndex < COMMAND_BUFFER_SIZE - 1)
+      {
+        commandBuffer[bufferIndex++] = incomingChar;
+      }
+    }
+  }
+}
+
 /******************************************************************************
    PRIVATE MEMBER FUNCTIONS
  ******************************************************************************/
@@ -147,9 +213,9 @@ void Arduino_DebugUtils::vPrint(char const * fmt, va_list args) {
   va_end(args_copy);
 
   if (_newline_on) {
-    _debug_output_stream->println(msg_buf);
+    _debug_io_stream->println(msg_buf);
   } else {
-    _debug_output_stream->print(msg_buf);
+    _debug_io_stream->print(msg_buf);
   }
 
 #if __STDC_NO_VLA__ == 1
@@ -193,7 +259,7 @@ void Arduino_DebugUtils::printTimestamp()
     snprintf(timestamp, sizeof(timestamp), "[ %lu ] ", millis());
   }
 
-  _debug_output_stream->print(timestamp);
+  _debug_io_stream->print(timestamp);
 }
 
 void Arduino_DebugUtils::printDebugLabel(int const debug_level)
@@ -211,7 +277,7 @@ void Arduino_DebugUtils::printDebugLabel(int const debug_level)
   if (!is_valid_debug_level)
     return;
 
-  _debug_output_stream->print(DEBUG_MODE_STRING[debug_level]);
+  _debug_io_stream->print(DEBUG_MODE_STRING[debug_level]);
 }
 
 bool Arduino_DebugUtils::shouldPrint(int const debug_level) const

src/Arduino_DebugUtils.h

@@ -70,6 +70,7 @@ class Arduino_DebugUtils {
     void print(int const debug_level, const char * fmt, ...);
     void print(int const debug_level, const __FlashStringHelper * fmt, ...);
 
+    void processDebugUpdateLevelCommand();   
 
   private:
 
@@ -78,7 +79,7 @@ class Arduino_DebugUtils {
     bool      _print_debug_label;
     bool      _format_timestamp_on;
     int       _debug_level;
-    Stream *  _debug_output_stream;
+    Stream *  _debug_io_stream;
 
     void vPrint(char const * fmt, va_list args);
     void printTimestamp();