/*********************************************************************
 This sketch controls an electronic circuit that can sense 
 the environment using a sensor (electronic components that convert 
 real-world measurements into electrical signals). The device 
 processes the information from the sensors with the behavior 
 described in the sketch. The device will then be able to interact 
 with the world by using actuators, electronic components that can 
 convert an electric signal into physical action.
 

*********************************************************************/

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


#define SCREEN_WIDTH 128 // display width, in pixels
#define SCREEN_HEIGHT 64 // display height, in pixels
#define OLED_RESET     4
#define SCREEN_ADDRESS 0x3D // OLED

const int sensorPin = A0;
const float alpha = 0.95; // Low Pass Filter alpha (0 - 1 )
const float aRef = 4.6; // analog reference
float filteredVal = 512.0; // midway starting point
float adcVal;
float voltage;
float psiVal;
float P1,P2,P3,P4,P5;

Adafruit_SSD1306 display(SCREEN_WIDTH, SCREEN_HEIGHT, &Wire, OLED_RESET);

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

  //analogReference(EXTERNAL);
  //analogReference(INTERNAL);

  //SSD1306_SWITCHCAPVCC = generate display voltage from 3.3V internally
  if (!display.begin(SSD1306_SWITCHCAPVCC, SCREEN_ADDRESS)) {
    Serial.println(F("SSD1306 allocation failed"));
    while (1); // Don't proceed, wait forever
  }
  display.clearDisplay();
  display.display();
}

void loop() {

  adcVal = (float)analogRead(A0); // Read pressure sensor val (A0)
  voltage = (adcVal / 1024.0) * aRef; // calculate voltage
  P1 = (voltage - 0.4784) / 0.0401; // x=(y-b)/m

  adcVal = (float)analogRead(A1); // Read pressure sensor val (A0)
  voltage = (adcVal / 1024.0) * aRef; // calculate voltage
  P2 = (voltage - 0.4784) / 0.0401; // x=(y-b)/m

	adcVal = (float)analogRead(A2); // Read pressure sensor val (A0)
  voltage = (adcVal / 1024.0) * aRef; // calculate voltage
  P3 = (voltage - 0.4784) / 0.0401; // x=(y-b)/m

	adcVal = (float)analogRead(A3); // Read pressure sensor val (A0)
  voltage = (adcVal / 1024.0) * aRef; // calculate voltage
  P4 = (voltage - 0.4784) / 0.0401; // x=(y-b)/m

	adcVal = (float)analogRead(A6); // Read pressure sensor val (A0)
  voltage = (adcVal / 1024.0) * aRef; // calculate voltage
  P5 = (voltage - 0.4784) / 0.0401; // x=(y-b)/m

  updateOLED ();

  delay(200);
}

void updateOLED () {
  display.clearDisplay();
  display.setTextSize(1);
  display.setTextColor(WHITE);

  display.setCursor(10, 3);
  display.print("P1= "); display.print(P1, 0);display.print(" psi");

	display.setCursor(10, 15);
	display.print("P2= "); display.print(P2, 0);display.print(" psi");
  
	display.setCursor(10, 27);
	display.print("P3= ");display.print(P3, 0);display.print(" psi");

	display.setCursor(10, 39);
	display.print("P4= "); display.print(P4, 0);display.print(" psi");

	display.setCursor(10, 51);
	display.print("P5= "); display.print(P5, 0);display.print(" psi");


  
  display.display();
}