//tx_rx03  Robert Hart Mar 2019.
//https://roberthart56.github.io/SCFAB/SC_lab/Sensors/tx_rx_sensors/index.html

//Modified from Adrián´s Adrianino´s step response: https://fabacademy.org/2020/labs/leon/students/adrian-torres/adrianino.html#step
//By: Pedro Chana :https://fabacademy.org/2022/labs/uemadrid/students/pedro-chana/assignment12.html
//Pin changes.
//Added digitalWriteFast.
//Added Oled screen output.

//Modified by Terrence Carew:http://fabacademy.org/2021/labs/vancouver/students/terrence-carew/assignments/final_project.html
//Added level variable.
//Added New Mapping.
//Added Intro display
//Added "millis()" function timing.
//Added more Pin associated devices.
//Added"level" response conditions.

#include <Wire.h>
#include <Adafruit_GFX.h>
#include <Adafruit_SSD1306.h>

#define SCREEN_WIDTH 128 // OLED display width, in pixels
#define SCREEN_HEIGHT 64 // OLED display height, in pixels

// Declaration for an SSD1306 display connected to I2C (SDA, SCL pins)
Adafruit_SSD1306 display(SCREEN_WIDTH, SCREEN_HEIGHT, &Wire, -1);


long result;   //variable for the result of the tx_rx measurement.
int analog_pin = A4; //  PA2 of the ATtiny3216
int tx_pin = A5;  //     PA1 of the ATtiny3216
int led1 = 2;
int led2 = 3;
int led3 = 4;
int midbtn = 15;
int relay1 = 10;
int relay2 = 11;
int relay3 = 12;
int relay4 = 13;
void setup() {
pinMode(tx_pin,OUTPUT);      //Pin 2 provides the voltage step
pinMode(2, OUTPUT);
pinMode(3, OUTPUT);
pinMode(4, OUTPUT);
pinMode(15, INPUT);
pinMode(10, OUTPUT);
pinMode(11, OUTPUT);
pinMode(12, OUTPUT);
pinMode(13, OUTPUT);
Serial.begin(115200);
  if(!display.begin(SSD1306_SWITCHCAPVCC, 0x3C)) {
    Serial.println(F("SSD1306 allocation failed"));
    for(;;);
  }
  delay(2000);
  display.clearDisplay();
  display.setTextColor(WHITE);
}


long tx_rx(){         //Function to execute rx_tx algorithm and return a value
                      //that depends on coupling of two electrodes.
                      //Value returned is a long integer.
  int read_high;
  int read_low;
  int diff;
  long int sum;
  int N_samples = 100;    //Number of samples to take.  Larger number slows it down, but reduces scatter.

  sum = 0;

  for (int i = 0; i < N_samples; i++){
   digitalWriteFast(tx_pin,HIGH);              //Step the voltage high on conductor 1.
   read_high = analogRead(analog_pin);        //Measure response of conductor 2.
   delayMicroseconds(100);            //Delay to reach steady state.
   digitalWriteFast(tx_pin,LOW);               //Step the voltage to zero on conductor 1.
   read_low = analogRead(analog_pin);         //Measure response of conductor 2.
   diff = read_high - read_low;       //desired answer is the difference between high and low.
 sum += diff;                       //Sums up N_samples of these measurements.
 }
  return sum;
}                         //End of tx_rx function.


void loop() {

  long level; // declares for  water level reading

  if (millis()< 3000){  // if microcontroller has been running less than 3 seconds.
      display.clearDisplay();
   
  // Name intro display 
  display.setTextSize(2);
  display.setCursor(0,0);
  display.print("Terrepon-X");
  display.print("");

  display.display();
  }
  delay(3000);

level = map(tx_rx(), 6500,12000, 0, 100);  // maps the level for readings
Serial.print("level:")
Serial.println(level);
delay(100);
delay(100);

  if (level < 1700){  //condition for if water is below a certain level
     //clear display
  display.clearDisplay();
   
  // display 
  display.setTextSize(1);
  display.setCursor(0,0);
  display.print("level:");
  display.setTextSize(2);
  display.setCursor(0,10);
  display.print("Too Low");
  display.print("");

  display.display();

  digitalWrite(led1, HIGH);
  digitalWrite(relay1, HIGH);
  digitalWrite(led2, HIGH);
  digitalWrite(relay2, HIGH);
  digitalWrite(led3, LOW);
  digitalWrite(relay4, LOW);
}
else if (level >=1700){  // condition if water is above or at acceptable level
     //clear display
  display.clearDisplay();
   
  // display 
  display.setTextSize(1);
  display.setCursor(0,0);
  display.print("level:");
  display.setTextSize(2);
  display.setCursor(0,10);
  display.print("Full");
  display.print("");

  display.display();

  digitalWrite(led1, LOW);
  digitalWrite(relay1, LOW);
  digitalWrite(led2, LOW);
  digitalWrite(relay2, LOW);
  digitalWrite(led3, HIGH);
  digitalWrite(relay4, HIGH);
}

}