SerialCommandManager is a lightweight Arduino/ESP library that parses structured serial commands with optional key/value parameters, routes them to registered handlers, and provides debug, error, and fallback support for robust serial communication.

This section shows how to use the SerialCommandManager library with Arduino or ESP boards.

It covers:

• Creating the manager
• Registering commands
• Using key/value parameters
• Handling unrecognized commands
• Sending debug and error messages

#include <Arduino.h> #include "SerialCommandManager.h"

Handlers receive:

• command – the command string
• params – array of key/value pairs
• paramCount – number of parameters
• context – optional user pointer

` // Handles DEBUG command void handleDebug(const String& command, StringKeyValue* params, int paramCount, void* context) { if (paramCount > 0 && params[0].key.equalsIgnoreCase("ON")) { Serial.println("Debug mode ENABLED"); } else if (paramCount > 0 && params[0].key.equalsIgnoreCase("OFF")) { Serial.println("Debug mode DISABLED"); } }

// Handles LED control command void handleLED(const String& command, StringKeyValue* params, int paramCount, void* context) { int pin = 13; bool state = false;

for (int i = 0; i < paramCount; i++)
{
    if (params[i].key.equalsIgnoreCase("pin")) pin = params[i].value.toInt();
    if (params[i].key.equalsIgnoreCase("state")) state = params[i].value.equalsIgnoreCase("ON");
}

pinMode(pin, OUTPUT);
digitalWrite(pin, state ? HIGH : LOW);

Serial.print("LED command processed: pin=");
Serial.print(pin);
Serial.print(", state=");
Serial.println(state ? "ON" : "OFF");

}

// Handles PING command void handlePing(const String& command, StringKeyValue* params, int paramCount, void* context) { Serial.println("PONG;"); }

// Default handler for unrecognized commands void handleUnknown(SerialCommandManager* mgr) { Serial.print("Unknown command received: "); Serial.println(mgr->getCommand()); Serial.print("Raw message: "); Serial.println(mgr->getRawMessage()); } `

// Arguments: // &Serial -> serial port // handleUnknown -> fallback callback for unknown commands // '\n' -> terminator // ':' -> command/parameter separator // '=' -> key/value separator // 500 -> timeout in ms // 256 -> maximum message size SerialCommandManager commandMgr(&Serial, handleUnknown, '\n', ':', '=', 500, 256);

` void setup() { Serial.begin(115200); delay(1000); Serial.println("SerialCommandManager Example Started");

// Register commands
commandMgr.registerHandler("DEBUG", handleDebug);
commandMgr.registerHandler("LED", handleLED);
commandMgr.registerHandler("PING", handlePing);

Serial.println("Ready to receive commands...");
Serial.println("Examples:");
Serial.println("  DEBUG:ON;");
Serial.println("  LED:pin=13,state=ON;");
Serial.println("  PING;");

} `

void loop() { commandMgr.readCommands(); // Continuously read serial input }

commandMgr.sendDebug("Status update", "Loop1");

commandMgr.sendError("Invalid command", "LED");

StringKeyValue params[2] = { {"pin", "12"}, {"state", "ON"} }; commandMgr.sendCommand("LED", "Update", "Controller1", params, 2);

• Handlers are case-insensitive for both commands and keys.
• Dynamic parameter arrays allow flexibility; you can parse as many key/value pairs as needed.
• The default/fallback callback ensures no message is ignored.
• Works on all Arduino and ESP platforms.