Week 9: Radio, WiFi, Bluetooth (IoT)

//Thermometer with thermistor
 
/*thermistor parameters:
 * RTI: 10 000 Ω
 * B: 3977 K +- 0.75%
 * TI:  25 C
 * +- 5%
 */
 
//These values are in the datasheet
#define RTI 10000   // Ω
#define B 3977      // K
//--------------------------------------
 
 
#define VCC 3.3    //Supply voltage
#define R 10000  //R=10KΩ
 
//Variables
float RT, VR, ln, TE, TI, VRT;
 
void setup() {
  Serial.begin(9600);
  TI = 25 + 273.15;                 //Temperature TI from datasheet, conversion from Celsius to kelvin
}
 
void loop() {
  VRT = analogRead(A0);              //Acquisition analog value of VRT
  Serial.println(VRT);
  VRT = (3.30 / 1023.00) * VRT;      //Conversion to voltage
  VR = VCC - VRT;
  RT = VRT / (VR / R);               //Resistance of RT
  Serial.println("RT/RTI");
  Serial.println(RT/RTI);
 
  ln = log(RT / RTI);
  Serial.println("Ln");
  Serial.println(ln);
  TE = (1 / ((ln / B) + (1 / TI))); //Temperature from thermistor
 
  TE = TE - 273.15 -11;                 //Conversion to Celsius
 
  // Serial.print("Temperature:");
  // Serial.print("\t");
 
 
  Serial.print(TE);
  Serial.print("C\t\t");
 
  Serial.print(TE + 273.15);        //Conversion to Kelvin
  Serial.print("K\t\t");
 
  Serial.print((TE * 1.8) + 32);    //Conversion to Fahrenheit
  Serial.print((TE * 1.8) + 32);
  Serial.println("F\t\t");
 
 
  delay(500);
 
 // if TE > 26
  //else
 
}
 

/*
Thermistor_read.  Robert Hart June 2020.
Using  datasheet for 10k NTC thermistor (Digikey Part No.).  https://www.vishay.com/docs/29049/ntcle100.pdf
with constants A and B to calculate Temperature from Resistance.
10K resitor in series to make a simple voltage divider.
*/
int ThermistorPin = A0;
int Vo;
float R1 = 10000;
float R2, T;
float A = 3.354e-03;
float B = 2.5698e-4;
 
void setup() {
Serial.begin(9600);
analogReadResolution(12);                 //Using a 32-bit ATSAM microcontroller that has up to 12 bit resolution. 4095 max.
}
 
void loop() {
 
  Vo = analogRead(ThermistorPin);
  R2 = R1 * 1/(4096.0 / (float)Vo - 1.0);         //Calculate resistance of thermistor from voltage divider math.
  T = (1.0 / (A + B*log(R2/R1) ));                 // Calculate temperature using datasheet formula.
  T = T - 273.15;                                   //Convert from Kelvin to Celcius.
 
 
  Serial.print("Temperature: ");
  Serial.print(T);
  Serial.println("C");
 
  delay(500);
}

// Load Wi-Fi library
#include <WiFi.h>
 
//Define for gas sensor
#define MQ4pin (A2) //changed from A0
float sensorValue;  //variable to store sensor value
 
// Replace with your network credentials
const char* ssid     = "ESP32-Access-Point";
const char* password = "123456789";
 
// Set web server port number to 80
WiFiServer server(80);
 
// Variable to store the HTTP request
String header;
 
 
//taken from Rob's code
int ThermistorPin = A3; //can't be A0 pin according to https://nathanmelenbrink.github.io/ps70/10_networking/setup.html
int Vo;
float R1 = 10000;
float R2, T;
float A = 3.354e-03;
float B = 2.5698e-4;
String TEString;
String temperatureState;
String gasState;
String overallState;
 
void setup() {
  Serial.begin(115200);
  analogReadResolution(12);                 //Using a 32-bit ATSAM microcontroller that has up to 12 bit resolution. 4095 max. Taken from Rob's code
  // Initialize the output variables as outputs
 
 
  // Connect to Wi-Fi network with SSID and password
  Serial.print("Setting AP (Access Point)…");
  // Remove the password parameter, if you want the AP (Access Point) to be open
  WiFi.softAP(ssid, password);
 
  IPAddress IP = WiFi.softAPIP();
  Serial.print("AP IP address: ");
  Serial.println(IP);
 
  server.begin();
}
 
void loop(){
  //Temperature
  Vo = analogRead(ThermistorPin);
  //Serial.println(ThermistorPin);
  R2 = R1 * 1/(4096.0 / (float)Vo - 1.0);         //Calculate resistance of thermistor from voltage divider math.
  T = (1.0 / (A + B*log(R2/R1) ));                 // Calculate temperature using datasheet formula.
  T = T - 273.15;                                   //Convert from Kelvin to Celcius.
 
 
  Serial.print("Temperature: ");
  Serial.print(T);
  Serial.println("C");
 
  delay(500);
  TEString = String(T);
  if (T>30) {
    temperatureState ="ready";
  } else {
    temperatureState = "not ready";
  }
 
  // Temperature end
 
  //Gas
   sensorValue = analogRead(MQ2pin); // read analog input pin 0
 
  Serial.print("Sensor Value: ");
  Serial.print(sensorValue);
 
  Serial.println("");
  delay(2000); // wait 2s for next reading
  if (sensorValue > 300) {
    gasState ="ready";
  } else {
    gasState = "not ready";
  }
 
  //Gas end
 
  //Overall Start
  if (gasState == "ready" & temperatureState == "ready") {
    overallState = "ready";
  } else {
    overallState = "not ready";
 
  }
  //Overall end
 
  WiFiClient client = server.available();   // Listen for incoming clients
 
  if (client) {                             // If a new client connects,
    Serial.println("New Client.");          // print a message out in the serial port
    String currentLine = "";                // make a String to hold incoming data from the client
    while (client.connected()) {            // loop while the client's connected
      if (client.available()) {             // if there's bytes to read from the client,
        char c = client.read();             // read a byte, then
        Serial.write(c);                    // print it out the serial monitor
        header += c;
        if (c == '\n') {                    // if the byte is a newline character
          // if the current line is blank, you got two newline characters in a row.
          // that's the end of the client HTTP request, so send a response:
          if (currentLine.length() == 0) {
            // HTTP headers always start with a response code (e.g. HTTP/1.1 200 OK)
            // and a content-type so the client knows what's coming, then a blank line:
            client.println("HTTP/1.1 200 OK");
            client.println("Content-type:text/html");
            client.println("Connection: close");
            client.println();
 
 
 
            // Display the HTML web page
            client.println("<!DOCTYPE html><html>");
            client.println("<head><meta name=\"viewport\" content=\"width=device-width, initial-scale=1\">");
            client.println("<link rel=\"icon\" href=\"data:,\">");
            // CSS to style the on/off buttons
            // Feel free to change the background-color and font-size attributes to fit your preferences
            client.println("<style>html { font-family: Helvetica; display: inline-block; margin: 0px auto; text-align: center;}");
            client.println(".button { background-color: #FF0000; border: none; color: white; padding: 16px 40px;"); //changed to Red
            client.println("text-decoration: none; font-size: 30px; margin: 2px; cursor: pointer;}");
            client.println(".button2 {background-color: #4CAF50 ;}</style></head>"); //changed to Green
 
            // Web Page Heading
            client.println("<body><h1>Is the compost of your composting toilet ready? </h1>");
 
 
            client.println("Temperature indicates that compost is " + temperatureState + "</p>");
            client.println("Temperature is " + TEString + "C" + "</p>");
            // If the output27State is off, it displays the ON button
            if (temperatureState=="not ready") {
              client.println("<p><a href=\"/26/on\"><button class=\"button\">NOT READY</button></a></p>");
            } else {
              client.println("<p><a href=\"/26/off\"><button class=\"button button2\">READY</button></a></p>");
            }
            client.println("</body></html>");
 
            // Gas website
 
            client.println("Gas levels indicate that compost is " + gasState + "</p>");
            client.println("Gas level is " + String(sensorValue) + " units" + "</p>");
              if (gasState == "not ready") {
              client.println("<p><a href=\"/27/on\"><button class=\"button\">NOT READY</button></a></p>");
            } else {
              client.println("<p><a href=\"/27/off\"><button class=\"button button2\">READY</button></a></p>");
            }
              client.println("</body></html>");
 
            // Overall
 
            client.println("Overall, your compost is " + overallState + "</p>");
            if (overallState == "not ready") {
              client.println("<p><a href=\"/27/on\"><button class=\"button\">NOT READY</button></a></p>");
            } else {
              client.println("<p><a href=\"/27/off\"><button class=\"button button2\">READY</button></a></p>");
            }
              client.println("</body></html>");
 
            // The HTTP response ends with another blank line
            client.println();
            // Break out of the while loop
            break;
          } else { // if you got a newline, then clear currentLine
            currentLine = "";
          }
        } else if (c != '\r') {  // if you got anything else but a carriage return character,
          currentLine += c;      // add it to the end of the currentLine
        }
      }
    }
    // Clear the header variable
    header = "";
    // Close the connection
    client.stop();
    Serial.println("Client disconnected.");
    Serial.println("");
 
}
}