RxPOTRev2

//This code is a modified version of the Client Sketch from Reference 1 Designed to Receive Potentiometer Readings on a Second ESP32 and Turn the Servo Motor to the Corresponding Angle
//The difference between Rev 0 and Rev 1 is that Rev 1 adds a second servo motor on GPIO19 (D19 on the 30-Pin Board) and a second POT on GPIO35 (D35 on 30-Pin Board)
//Rev 2 is testing this code on two 38-pin ESPs sourced from the link referenced under Board Source 1 at the bottom of this file and to use 6 servo motors instead of just two
/*
  Rui Santos
  Complete project details at https://RandomNerdTutorials.com/esp32-client-server-wi-fi/

  Permission is hereby granted, free of charge, to any person obtaining a copy
  of this software and associated documentation files.

  The above copyright notice and this permission notice shall be included in all
  copies or substantial portions of the Software.
*/

#include <WiFi.h> //Used for WiFi
#include <HTTPClient.h> //Used for WiFi
#include <ESP32Servo.h> //To Work with Servo Motor
#include <String.h> //To Convert String to Integer

const char* ssid = "ESP32-Access-Point"; //Changed these credentials for the Rev 2 sketch so it doesn't interfere with my other similar project for 2 servo control
const char* password = "123456789";

//Your IP address or domain name with URL path
const char* serverNameAngleOne = "http://192.168.4.1/angleOne"; //1st POT Angle
const char* serverNameAngleTwo = "http://192.168.4.1/angleTwo"; //2nd POT Angle
const char* serverNameAngleThree = "http://192.168.4.1/angleThree"; //3rd POT Angle
const char* serverNameAngleFour = "http://192.168.4.1/angleFour"; //4th POT Angle
const char* serverNameAngleFive = "http://192.168.4.1/angleFive"; //5th POT Angle
const char* serverNameAngleSix = "http://192.168.4.1/angleSix"; //6th POT Angle

Servo myservoOne;  //Create servo object to control a servo - 1st Servo Motor
Servo myservoTwo;  //Create servo object to control a servo - 2nd Servo Motor
Servo myservoThree;  //Create servo object to control a servo - 3rd Servo Motor
Servo myservoFour;  //Create servo object to control a servo - 4th Servo Motor
Servo myservoFive;  //Create servo object to control a servo - 5th Servo Motor
Servo myservoSix;  //Create servo object to control a servo - 6th Servo Motor

// Possible PWM GPIO pins on the ESP32: 0(used by on-board button),2,4,5(used by on-board LED),12-19,21-23,25-27,32-33
//On 38-pin board the following pins were used - See Diagram for Board Source 1
int servoPinOne = 16;      //GPIO pin used to connect the servo control (digital out) for Servo One - Labeled G16 on board and also RX2 on diagram
int servoPinTwo = 17;      //GPIO pin used to connect the servo control (digital out) for Servo Two - Labeled G17 on board and also TX2 on diagram
int servoPinThree = 18;      //GPIO pin used to connect the servo control (digital out) for Servo Three - Labeled G18 on board and also VSPI SCK on diagram
int servoPinFour = 19;      //GPIO pin used to connect the servo control (digital out) for Servo Four - Labeled G19 on board and also VSPI MISO on diagram
int servoPinFive = 21;      //GPIO pin used to connect the servo control (digital out) for Servo Five - Labeled G21 on board and also I2C SDA on diagram
int servoPinSix = 22;      //GPIO pin used to connect the servo control (digital out) for Servo Five - Labeled G22 on board and also I2C SCL on diagram

// Possible ADC pins on the ESP32: 0,2,4,12-15,32-39; 34-39 are recommended for analog input
int ADC_Max = 4096;     // This is the default ADC max value on the ESP32 (12 bit ADC width);
                        // this width can be set (in low-level oode) from 9-12 bits, for a
                        // a range of max values of 512-4096

int angleIntOne; //Variable to Store Angle One Converted from String Back to an Integer
String angleOne; //Variable to Store Received Angle One Which Is a String Type Variable

int angleIntTwo; //Variable to Store Angle Two Converted from String Back to an Integer
String angleTwo; //Variable to Store Received Angle Two Which Is a String Type Variable

int angleIntThree; //Variable to Store Angle Three Converted from String Back to an Integer
String angleThree; //Variable to Store Received Angle Three Which Is a String Type Variable

int angleIntFour; //Variable to Store Angle Four Converted from String Back to an Integer
String angleFour; //Variable to Store Received Angle Four Which Is a String Type Variable

int angleIntFive; //Variable to Store Angle Five Converted from String Back to an Integer
String angleFive; //Variable to Store Received Angle Five Which Is a String Type Variable

int angleIntSix; //Variable to Store Angle Six Converted from String Back to an Integer
String angleSix; //Variable to Store Received Angle Six Which Is a String Type Variable

unsigned long previousMillis = 0;
const long interval = 100; //Reference 1 said this value was arbitrary - I changed it from 5000 to 100 ms

void setup() {
  Serial.begin(115200); //Start the serial monitor for debugging purposes

  //Setup the Servo Motor
  // Allow allocation of all timers
  ESP32PWM::allocateTimer(0);
  ESP32PWM::allocateTimer(1);
  ESP32PWM::allocateTimer(2);
  ESP32PWM::allocateTimer(3);
  myservoOne.setPeriodHertz(50);  //Standard 50hz servo
  myservoOne.attach(servoPinOne, 1000, 2000);   // attaches the servo on servoPinOne to the servo object
                                         // using SG90 or MG90S small servo min/max of 500us and 2400us
                                         // for MG995 or MG996R large servo, use 1000us and 2000us,
                                         // which are the defaults, so this line could be
                                         // "myservoOne.attach(servoPinOne);"

  myservoTwo.setPeriodHertz(50);  //Standard 50hz servo
  myservoTwo.attach(servoPinTwo, 500, 2400);   //attaches the servo on servoPinTwo to the servo object
                                         // using SG90 or MG90S small servo min/max of 500us and 2400us
                                         // for MG995 or MG996R large servo, use 1000us and 2000us,
                                         // which are the defaults, so this line could be
                                         // "myservoTwo.attach(servoPinTwo);"

  myservoThree.setPeriodHertz(50);  //Standard 50hz servo
  myservoThree.attach(servoPinThree, 500, 2400);   //attaches the servo on servoPinThree to the servo object
                                         // using SG90 or MG90S small servo min/max of 500us and 2400us
                                         // for MG995 or MG996R large servo, use 1000us and 2000us,
                                         // which are the defaults, so this line could be
                                         // "myservoThree.attach(servoPinThree);"

  myservoFour.setPeriodHertz(50);  //Standard 50hz servo
  myservoFour.attach(servoPinFour, 500, 2400);   //attaches the servo on servoPinFour to the servo object
                                         // using SG90 or MG90S small servo min/max of 500us and 2400us
                                         // for MG995 or MG996R large servo, use 1000us and 2000us,
                                         // which are the defaults, so this line could be
                                         // "myservoFour.attach(servoPinFour);"

  myservoFive.setPeriodHertz(50);  //Standard 50hz servo
  myservoFive.attach(servoPinFive, 500, 2400);   //attaches the servo on servoPinFive to the servo object
                                         // using SG90 or MG90S small servo min/max of 500us and 2400us
                                         // for MG995 or MG996R large servo, use 1000us and 2000us,
                                         // which are the defaults, so this line could be
                                         // "myservoFive.attach(servoPinFive);"

  myservoSix.setPeriodHertz(50);  //Standard 50hz servo
  myservoSix.attach(servoPinSix, 500, 2400);   //attaches the servo on servoPinSix to the servo object
                                         // using SG90 or MG90S small servo min/max of 500us and 2400us
                                         // for MG995 or MG996R large servo, use 1000us and 2000us,
                                         // which are the defaults, so this line could be
                                         // "myservoSix.attach(servoPinSix);"

  //Connect the ESP32 client to the ESP32 server network
  WiFi.begin(ssid, password);
  Serial.println("Connecting");
  while(WiFi.status() != WL_CONNECTED) {
    delay(500);
    Serial.print(".");
  }
  Serial.println("");
  Serial.print("Connected to WiFi network with IP Address: ");
  Serial.println(WiFi.localIP());
}

void loop() {
  unsigned long currentMillis = millis();

  if(currentMillis - previousMillis >= interval) {
     // Check WiFi connection status
    if(WiFi.status()== WL_CONNECTED ){
      angleOne = httpGETRequest(serverNameAngleOne); //Gets the servo angle from the web server of the transmitting ESP32 and stores to a variable
      Serial.println("AngleOne: " + angleOne + "°"); //Prints results to serial monitor for debugging
      angleTwo = httpGETRequest(serverNameAngleTwo);
      Serial.println("AngleTwo: " + angleTwo + "°");
      angleThree = httpGETRequest(serverNameAngleThree);
      Serial.println("AngleThree: " + angleThree + "°");
      angleFour = httpGETRequest(serverNameAngleFour);
      Serial.println("AngleFour: " + angleFour + "°");
      angleFive = httpGETRequest(serverNameAngleFive);
      Serial.println("AngleFive: " + angleFive + "°");
      angleSix = httpGETRequest(serverNameAngleSix);
      Serial.println("AngleSix: " + angleSix + "°");

      angleIntOne = angleOne.toInt(); //Converts angleOne back to an integer
      angleIntTwo = angleTwo.toInt(); //Converts angleTwo back to an integer
      angleIntThree = angleThree.toInt(); //Converts angleThree back to an integer
      angleIntFour = angleFour.toInt(); //Converts angleFour back to an integer
      angleIntFive = angleFive.toInt(); //Converts angleFive back to an integer
      angleIntSix = angleSix.toInt(); //Converts angleSix back to an integer

      myservoOne.write(angleIntOne);       //set the servo position according to the scaled value
      delay(200);                          //wait for the servo to get there

      myservoTwo.write(angleIntTwo);       //set the servo position according to the scaled value
      delay(200);                          //wait for the servo to get there

      myservoThree.write(angleIntThree);   //set the servo position according to the scaled value
      delay(200);                          //wait for the servo to get there

      myservoFour.write(angleIntFour);     //set the servo position according to the scaled value
      delay(200);                          //wait for the servo to get there

      myservoFive.write(angleIntFive);     //set the servo position according to the scaled value
      delay(200);                          //wait for the servo to get there

      myservoSix.write(angleIntSix);       //set the servo position according to the scaled value
      delay(200);                          //wait for the servo to get there

      //save the last HTTP GET Request
      previousMillis = currentMillis;
    }
    else {
      Serial.println("WiFi Disconnected");
    }
  }
}

//WiFi Related Function Definitions
String httpGETRequest(const char* serverName) {
  WiFiClient client;
  HTTPClient http;

  // Your Domain name with URL path or IP address with path
  http.begin(client, serverName);

  // Send HTTP POST request
  int httpResponseCode = http.GET();

  String payload = "--";

  if (httpResponseCode>0) {
    Serial.print("HTTP Response code: ");
    Serial.println(httpResponseCode);
    payload = http.getString();
  }
  else {
    Serial.print("Error code: ");
    Serial.println(httpResponseCode);
  }
  // Free resources
  http.end();

  return payload;
}

//References
//Reference 1 How to Send Sensor Data from ESP32 to ESP32 Article https://randomnerdtutorials.com/esp32-client-server-wi-fi/
//Reference 2 How to Work with ESP32 and Servo Motors Article https://dronebotworkshop.com/esp32-servo/
//Reference 3 ESP32 Pinout Reference: Which GPIO pins should you use? https://randomnerdtutorials.com/esp32-pinout-reference-gpios/ - I found this diagram helpful to double check Board Source 1's diagram

//Board Source 1- https://www.aliexpress.com/item/32959541446.html?spm=a2g0o.9042311.0.0.5fda4c4dj8KyU3
//Diagram "Pinout for 38-Pin Version.jpg" in D:\Stuff\Projects\ESP32 Control\Sources\ESP32 Development Board Page