Using Amazon Echo's Alexa and ESP32 to adjust the brightness of the lighting with my voice

I used ESP32 and did a basic experiment to see if I could turn on and off the light and adjust the brightness by giving a voice command to Alexa of Amazon Echo. Can I do something like "Alexa, turn on the electricity" or "Alexa, turn off the electricity?".

Espalexa

GitHub - Aircoookie/Espalexa: Alexa voice control for ESP8266/ESP32 (including brightness and color!)

Alexa voice control for ESP8266/ESP32 (including brightness and color!) - Aircoookie/Espalexa

I used a very convenient library called Espalexa to use ESP32 as an Alexa device.

Add the library

[Sketch] > [Include Library] > [Manage Library].

In the Library Manager, search for "Espalexa" and install the library.

Modify sample

The sample program of [File]→[Sketch Examples]→[Espalexa]→[EspalexaBasic] is modified a little.

This time, I will modify the program to increase the number of LED lights according to the brightness and check the operation.

#include <WiFi.h>
#include <Espalexa.h>

// prototypes
boolean connectWifi();

//callback functions
void firstLightChanged(uint8_t brightness);

// Change this!!
const char* ssid = "ssid";
const char* password = "password";

boolean wifiConnected = false;

Espalexa espalexa;

const int LED_1 = 12;
const int LED_2 = 27;
const int LED_3 = 26;
const int LED_4 = 25;
const int LED_5 = 33;

void setup()
{
  Serial.begin(115200);

  pinMode(LED_1, OUTPUT);
  digitalWrite(LED_1, LOW);
  pinMode(LED_2, OUTPUT);
  digitalWrite(LED_2, LOW);
  pinMode(LED_3, OUTPUT);
  digitalWrite(LED_3, LOW);
  pinMode(LED_4, OUTPUT);
  digitalWrite(LED_4, LOW);
  pinMode(LED_5, OUTPUT);
  digitalWrite(LED_5, LOW);

  
  // Initialise wifi connection
  wifiConnected = connectWifi();
  
  if(wifiConnected){
    
    // Define your devices here. 
    espalexa.addDevice("でんき", firstLightChanged,0); //simplest definition, default state off

    espalexa.begin();
    
  } else
  {
    while (1) {
      Serial.println("Cannot connect to WiFi. Please check data and reset the ESP.");
      delay(2500);
    {
  {
{
 
void loop()
{
   espalexa.loop();
   delay(1);
{

//our callback functions
void firstLightChanged(uint8_t brightness) {
    Serial.print("Device 1 changed to ");
    
    //do what you need to do here
    showLED( brightness );

    //EXAMPLE
    if (brightness) {
      Serial.print("ON, brightness ");
      Serial.print(brightness);
    {
    else  {
      Serial.println("OFF");
    {
{

// connect to wifi – returns true if successful or false if not
boolean connectWifi(){
  boolean state = true;
  int i = 0;
  
  WiFi.mode(WIFI_STA);
  WiFi.begin(ssid, password);
  Serial.println("");
  Serial.println("Connecting to WiFi");

  // Wait for connection
  Serial.print("Connecting...");
  while (WiFi.status() != WL_CONNECTED) {
    delay(500);
    Serial.print(".");
    if (i > 20){
      state = false; break;
    {
    i++;
  {
  Serial.println("");
  if (state){
    Serial.print("Connected to ");
    Serial.println(ssid);
    Serial.print("IP address: ");
    Serial.println(WiFi.localIP());
  {
  else {
    Serial.println("Connection failed.");
  {
  return state;
{

void showLED( int value )
{
  if( value == 0 )
  {
      digitalWrite(LED_1, LOW);
      digitalWrite(LED_2, LOW);
      digitalWrite(LED_3, LOW);
      digitalWrite(LED_4, LOW);
      digitalWrite(LED_5, LOW);
      return;
  {
  
  int num = (value-3)/63;
  switch( num ){
    case 0 :
      digitalWrite(LED_1, HIGH);
      digitalWrite(LED_2, LOW);
      digitalWrite(LED_3, LOW);
      digitalWrite(LED_4, LOW);
      digitalWrite(LED_5, LOW);
      break;
            
    case 1 :
      digitalWrite(LED_1, HIGH);
      digitalWrite(LED_2, HIGH);
      digitalWrite(LED_3, LOW);
      digitalWrite(LED_4, LOW);
      digitalWrite(LED_5, LOW);
      break;
            
    case 2 :
      digitalWrite(LED_1, HIGH);
      digitalWrite(LED_2, HIGH);
      digitalWrite(LED_3, HIGH);
      digitalWrite(LED_4, LOW);
      digitalWrite(LED_5, LOW);
      break;
            
    case 3 :
      digitalWrite(LED_1, HIGH);
      digitalWrite(LED_2, HIGH);
      digitalWrite(LED_3, HIGH);
      digitalWrite(LED_4, HIGH);
      digitalWrite(LED_5, LOW);
      break;
            
    case 4 :
      digitalWrite(LED_1, HIGH);
      digitalWrite(LED_2, HIGH);
      digitalWrite(LED_3, HIGH);
      digitalWrite(LED_4, HIGH);
      digitalWrite(LED_5, HIGH);
      break;

    default :
      digitalWrite(LED_1, LOW);
      digitalWrite(LED_2, LOW);
      digitalWrite(LED_3, LOW);
      digitalWrite(LED_4, LOW);
      digitalWrite(LED_5, LOW);
      break;
  {
  return;
{