In this video we learn how to control RGB LED color over the internet using MQTT protocol. We will explained RGB LED, RGB Color, MQTT, setting up Adafruit IO dashboard so we are able to control the color of RGB LED

Topics in this lesson

Use Chapters from timeline or click on the time

00:00 Introduction
2:23 Introduction to the project
4:43 What is MQTT
7:55 Adafruit IO setup
14:09 Wiring explained
16:07 Code explained
27:03 Selecting ESP32 board and COM port on Arduino IDE
29:12 Project demonstration
31:25 What is RGB LED?
35:26 RGB Color

/***********************************************************************
 This is Arduino sketch for ESP32 to control RGB LED using MQTT service of Adafruit
 www.Robojax.com
 Written By Ahamd Shamshiri
 on Feb 18, 2024

Adafruit MQTT Library ESP32 Adafruit IO SSL/TLS example

/// ref: https://www.electronicwings.com/esp32/esp32-mqtt-client
*/
// Define RGB LED pins
const int redPin = 27;
const int greenPin = 26;
const int bluePin = 25;

// Define PWM channels 
const int redChannel = 0;
const int greenChannel = 1;
const int blueChannel = 2;

// Define PWM frequency and resolution
const int freq = 5000;
const int resolution = 8;
int colorR, colorG, colorB;

#include <WiFi.h>
#include "WiFiClientSecure.h"
#include "Adafruit_MQTT.h"
#include "Adafruit_MQTT_Client.h"

/************************* WiFi Access Point *********************************/

#define WLAN_SSID "Book"
#define WLAN_PASS "888-888"

/************************* Adafruit.io Setup *********************************/

#define AIO_SERVER "io.adafruit.com"

// Using port 8883 for MQTTS
#define AIO_SERVERPORT 8883

// Adafruit IO Account Configuration
// (to obtain these values, visit https://io.adafruit.com and click on Active Key)
// #define AIO_USERNAME "YOUR_ADAFRUIT_IO_USERNAME"
// #define AIO_KEY      "YOUR_ADAFRUIT_IO_KEY"

#define AIO_USERNAME "robojax"
#define AIO_KEY "aio_NBQQ75Rn7liRNcRn5uGUBMsBYmjD"

/************ Global State (you don't need to change this!) ******************/

// WiFiFlientSecure for SSL/TLS support
WiFiClientSecure client;

// Setup the MQTT client class by passing in the WiFi client and MQTT server and login details.
Adafruit_MQTT_Client mqtt(&client, AIO_SERVER, AIO_SERVERPORT, AIO_USERNAME, AIO_KEY);

// io.adafruit.com root CA
const char* adafruitio_root_ca = \
      "-----BEGIN CERTIFICATE-----\n"
      "MIIEjTCCA3WgAwIBAgIQDQd4KhM/xvmlcpbhMf/ReTANBgkqhkiG9w0BAQsFADBh\n"
      "MQswCQYDVQQGEwJVUzEVMBMGA1UEChMMRGlnaUNlcnQgSW5jMRkwFwYDVQQLExB3\n"
      "d3cuZGlnaWNlcnQuY29tMSAwHgYDVQQDExdEaWdpQ2VydCBHbG9iYWwgUm9vdCBH\n"
      "MjAeFw0xNzExMDIxMjIzMzdaFw0yNzExMDIxMjIzMzdaMGAxCzAJBgNVBAYTAlVT\n"
      "MRUwEwYDVQQKEwxEaWdpQ2VydCBJbmMxGTAXBgNVBAsTEHd3dy5kaWdpY2VydC5j\n"
      "b20xHzAdBgNVBAMTFkdlb1RydXN0IFRMUyBSU0EgQ0EgRzEwggEiMA0GCSqGSIb3\n"
      "DQEBAQUAA4IBDwAwggEKAoIBAQC+F+jsvikKy/65LWEx/TMkCDIuWegh1Ngwvm4Q\n"
      "yISgP7oU5d79eoySG3vOhC3w/3jEMuipoH1fBtp7m0tTpsYbAhch4XA7rfuD6whU\n"
      "gajeErLVxoiWMPkC/DnUvbgi74BJmdBiuGHQSd7LwsuXpTEGG9fYXcbTVN5SATYq\n"
      "DfbexbYxTMwVJWoVb6lrBEgM3gBBqiiAiy800xu1Nq07JdCIQkBsNpFtZbIZhsDS\n"
      "fzlGWP4wEmBQ3O67c+ZXkFr2DcrXBEtHam80Gp2SNhou2U5U7UesDL/xgLK6/0d7\n"
      "6TnEVMSUVJkZ8VeZr+IUIlvoLrtjLbqugb0T3OYXW+CQU0kBAgMBAAGjggFAMIIB\n"
      "PDAdBgNVHQ4EFgQUlE/UXYvkpOKmgP792PkA76O+AlcwHwYDVR0jBBgwFoAUTiJU\n"
      "IBiV5uNu5g/6+rkS7QYXjzkwDgYDVR0PAQH/BAQDAgGGMB0GA1UdJQQWMBQGCCsG\n"
      "AQUFBwMBBggrBgEFBQcDAjASBgNVHRMBAf8ECDAGAQH/AgEAMDQGCCsGAQUFBwEB\n"
      "BCgwJjAkBggrBgEFBQcwAYYYaHR0cDovL29jc3AuZGlnaWNlcnQuY29tMEIGA1Ud\n"
      "HwQ7MDkwN6A1oDOGMWh0dHA6Ly9jcmwzLmRpZ2ljZXJ0LmNvbS9EaWdpQ2VydEds\n"
      "b2JhbFJvb3RHMi5jcmwwPQYDVR0gBDYwNDAyBgRVHSAAMCowKAYIKwYBBQUHAgEW\n"
      "HGh0dHBzOi8vd3d3LmRpZ2ljZXJ0LmNvbS9DUFMwDQYJKoZIhvcNAQELBQADggEB\n"
      "AIIcBDqC6cWpyGUSXAjjAcYwsK4iiGF7KweG97i1RJz1kwZhRoo6orU1JtBYnjzB\n"
      "c4+/sXmnHJk3mlPyL1xuIAt9sMeC7+vreRIF5wFBC0MCN5sbHwhNN1JzKbifNeP5\n"
      "ozpZdQFmkCo+neBiKR6HqIA+LMTMCMMuv2khGGuPHmtDze4GmEGZtYLyF8EQpa5Y\n"
      "jPuV6k2Cr/N3XxFpT3hRpt/3usU/Zb9wfKPtWpoznZ4/44c1p9rzFcZYrWkj3A+7\n"
      "TNBJE0GmP2fhXhP1D/XVfIW/h0yCJGEiV9Glm/uGOa3DXHlmbAcxSyCRraG+ZBkA\n"
      "7h4SeM6Y8l/7MBRpPCz6l8Y=\n"
      "-----END CERTIFICATE-----\n";

/****************************** Feeds ***************************************/

// Setup a feed called 'test' for publishing and 'test2' for subscription.
// Notice MQTT paths for AIO follow the form: <username>/feeds/<feedname>
Adafruit_MQTT_Subscribe COLOR_R = Adafruit_MQTT_Subscribe(&mqtt, AIO_USERNAME "/feeds/rgb-led-color.red");
Adafruit_MQTT_Subscribe COLOR_G = Adafruit_MQTT_Subscribe(&mqtt, AIO_USERNAME "/feeds/rgb-led-color.green");
Adafruit_MQTT_Subscribe COLOR_B = Adafruit_MQTT_Subscribe(&mqtt, AIO_USERNAME "/feeds/rgb-led-color.blue");
Adafruit_MQTT_Subscribe COLOR_RGB = Adafruit_MQTT_Subscribe(&mqtt, AIO_USERNAME "/feeds/color-picker");

/*************************** Sketch Code ************************************/

void setup() {
  // Set up PWM channels
  ledcSetup(redChannel, freq, resolution);
  ledcSetup(greenChannel, freq, resolution);
  ledcSetup(blueChannel, freq, resolution);

// Attach pins to corresponding PWM channels
  ledcAttachPin(redPin, redChannel);
  ledcAttachPin(greenPin, greenChannel);
  ledcAttachPin(bluePin, blueChannel);

Serial.begin(115200);
  delay(10);

Serial.println(F("Adafruit IO MQTTS (SSL/TLS) Example"));

// Connect to WiFi access point.
  Serial.println();
  Serial.println();
  Serial.print("Connecting to ");
  Serial.println(WLAN_SSID);

delay(1000);

WiFi.begin(WLAN_SSID, WLAN_PASS);
  delay(2000);

while (WiFi.status() != WL_CONNECTED) {
    delay(500);
    Serial.print(".");
  }
  Serial.println();

Serial.println("WiFi connected");
  Serial.println("IP address: ");
  Serial.println(WiFi.localIP());

// Set Adafruit IO's root CA
  client.setCACert(adafruitio_root_ca);

// register callback for feed
  COLOR_R.setCallback(color_R_Callback);
  // Setup MQTT subscription for time feed.
  mqtt.subscribe(&COLOR_R);

// register callback for feed
  COLOR_G.setCallback(color_G_Callback);
  // Setup MQTT subscription for time feed.
  mqtt.subscribe(&COLOR_G);

// register callback for feed
  COLOR_B.setCallback(color_B_Callback);
  // Setup MQTT subscription for time feed.
  mqtt.subscribe(&COLOR_B);

// register callback for feed
  COLOR_RGB.setCallback(color_RGB_Callback);
  // Setup MQTT subscription for time feed.
  mqtt.subscribe(&COLOR_RGB);

}

// uint32_t x=0;

void loop() {

// Ensure the connection to the MQTT server is alive (this will make the first
  // connection and automatically reconnect when disconnected).  See the MQTT_connect
  // function definition further below.
  MQTT_connect();

Serial.print("R: ");
  Serial.print (colorR);
  Serial.print(" G: ");
  Serial.print (colorG);
  Serial.print(" B: ");
  Serial.println(colorB);

// wait 0.5 seconds for subscription messages
  mqtt.processPackets(500);
  setColor();

// wait a couple seconds to avoid rate limit
  //delay(2000);
}

void color_R_Callback(char* message, uint16_t len) {
  char messageBuffer[40];
  //snprintf(messageBuffer, sizeof(messageBuffer), "Color status is :: %s, len :: %u", message, len);
  //Serial.println(messageBuffer);
  Serial.println(message);
  String inString = message;//sotre the message to String
 
  colorR  =  inString.toInt();//convert the message to Integer
  if(colorR >255 || colorR < 0)
  {
    colorR = 0;
  }
 
}

void color_G_Callback(char* message, uint16_t len) {
  char messageBuffer[40];
  //snprintf(messageBuffer, sizeof(messageBuffer), "Color status is :: %s, len :: %u", message, len);
  //Serial.println(messageBuffer);
  Serial.println(message);
  String inString = message;//sotre the message to String
 
  colorG  =  inString.toInt();//convert the message to Integer
  if(colorG >255 || colorG < 0)
  {
    colorG = 0;
  }
 
}

void color_B_Callback(char* message, uint16_t len) {
  char messageBuffer[40];
  //snprintf(messageBuffer, sizeof(messageBuffer), "Color status is :: %s, len :: %u", message, len);
  //Serial.println(messageBuffer);
  Serial.println(message);
  String inString = message;//sotre the message to String
 
  colorB  =  inString.toInt();//convert the message to Integer
  if(colorB >255 || colorB < 0)
  {
    colorB = 0;
  }
 
}

void color_RGB_Callback(char* message, uint16_t len) {
  char messageBuffer[40];
  //snprintf(messageBuffer, sizeof(messageBuffer), "Color status is :: %s, len :: %u", message, len);
  //Serial.println(messageBuffer);
  Serial.println(message);
  String newColor = String( message);//
  if(newColor.length() == 7)
  {
     
    String theColorR = newColor.substring(1, 3);//extract B2 from  #B2a48d for example
    String theColorG = newColor.substring(3, 5);//extract a4 from  #B2a48d for example
    String theColorB = newColor.substring(5, 7);//extract 8d from  #B2a48d for example
    
    colorR = StrToHex(theColorR.c_str());//convert String to HEX for R
    colorG = StrToHex(theColorG.c_str());//convert String to HEX for G
    colorB = StrToHex(theColorB.c_str());//convert String to HEX for B

}

//from https://stackoverflow.com/questions/44683071/convert-string-as-hex-to-hexadecimal
uint64_t StrToHex(const char* str)
{
  return (uint64_t) strtoull(str, 0, 16);
}

void setColor() {
  // For common-anode RGB LEDs, use 255 minus the color value
  ledcWrite(redChannel, colorR);
  ledcWrite(greenChannel, colorG);
  ledcWrite(blueChannel, colorB);
}

// Function to connect and reconnect as necessary to the MQTT server.
// Should be called in the loop function and it will take care if connecting.
void MQTT_connect() {
  int8_t ret;
  // Stop if already connected.
  if (mqtt.connected()) {
    return;
  }
  Serial.print("Connecting to MQTT... ");
  uint8_t retries = 3;
  while ((ret = mqtt.connect()) != 0) {  // connect will return 0 for connected
    Serial.println(mqtt.connectErrorString(ret));
    Serial.println("Retrying MQTT connection in 5 seconds...");
    mqtt.disconnect();
    delay(5000);  // wait 5 seconds
    retries--;
    if (retries == 0) {
      // basically die and wait for WDT to reset me
      while (1)
        ;
    }
  }
  Serial.println("MQTT Connected!");
}


 /*
Watch video instruction for this code on YouTube https://youtu.be/OUgyPXNYg3g
Resource page for this lesson and code:
http://robojax.com/course3
Tutoril by https://youTube.com/@robojax

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ESP32 IoT Tutorial 50/55 - Control RGB LED from anywhere in the world | SunFounder's ESP32 kit

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