/*
 * 
 * Arduino Sketch for Allegro ACS758 Current Sensor with LCD1602 & I2C module and current protection
 * This sensor can measure current at a range of up to 200A. It has overcurrent protection with a relay to disconnect the load if 
 * the current reaches beyond the limit.
 * It operates with 3.3V or 5V.
 * This sketch requires you to watch the following 2 videos before using this code:
 * 1- ACS758 Sensor https://www.youtube.com/watch?v=SiHfjzcqnU4
 * 2- LCD1602 with I2C https://www.youtube.com/watch?v=q9YC_GVHy5A
 * 3- Combined 1 and 2 in one video https://www.youtube.com/watch?v=tug9wjCwDQA
 * 4- Allegro ACS with Robojax Library (latest video and code) https://youtu.be/sB6EULTix2k
 * 
 * Written by Ahmad Shamshiri on Tuesday, June 26, 2018 at 17:56 in Ajax, Ontario, Canada
 * for Robojax.com
 * You can watch a detailed video on the ACS758 Current sensor at: https://youtu.be/SiHfjzcqnU4
 * This code has been explained in this video: https://youtu.be/GE4I10IZ1jY
 * This code has been downloaded from Robojax.com
 */
#define VIN A0 // define the Arduino pin A0 as voltage input (V in)
const int relayPin = 2;// set a digital pin for relay
const float VCC   = 5.0;// supply voltage 5V or 3.3V. If using PCB, set to 5V only.
const int model = 2;   // enter the model (see below)

const float maxCurrent = 15.00;// set maximum Current 
int maxCurrentWait = 6000;// wait time before current is connected

float minCurrent = 1.00;// reading cutt-off current. 1.00 is 1 Amper

/*
          "ACS758LCB-050B",// for model use 0
          "ACS758LCB-050U",// for model use 1
          "ACS758LCB-100B",// for model use 2
          "ACS758LCB-100U",// for model use 3
          "ACS758KCB-150B",// for model use 4
          "ACS758KCB-150U",// for model use 5
          "ACS758ECB-200B",// for model use 6
          "ACS758ECB-200U"// for model use  7   
The sensitivity array holds the sensitivity of the ACS758
current sensors. Do not change.          
*/
float sensitivity[] ={
          40.0,// for ACS758LCB-050B
          60.0,// for ACS758LCB-050U
          20.0,// for ACS758LCB-100B
          40.0,// for ACS758LCB-100U
          13.3,// for ACS758KCB-150B
          16.7,// for ACS758KCB-150U
          10.0,// for ACS758ECB-200B
          20.0,// for ACS758ECB-200U     
         }; 

/*         
 *   Quiescent output voltage is a factor of VCC that appears at the output       
 *   when the current is zero. 
 *   For bidirectional sensors it is 0.5 x VCC
 *   For unidirectional sensors it is 0.12 x VCC
 *   For model ACS758LCB-050B, the B at the end represents Bidirectional (polarity doesn't matter)
 *   For model ACS758LCB-100U, the U at the end represents Unidirectional (polarity must match)
 *    Do not change.
 */
float quiescent_Output_voltage [] ={
          0.5,// for ACS758LCB-050B
          0.12,// for ACS758LCB-050U
          0.5,// for ACS758LCB-100B
          0.12,// for ACS758LCB-100U
          0.5,// for ACS758KCB-150B
          0.12,// for ACS758KCB-150U
          0.5,// for ACS758ECB-200B
          0.12,// for ACS758ECB-200U            
          };
const float FACTOR = sensitivity[model]/1000;// set sensitivity for selected model
const float QOV =   quiescent_Output_voltage [model] * VCC;// set quiescent Output voltage for selected model
float voltage;// internal variable for voltage


// ======== start of LCD1602 with i2C settings
#include <Wire.h> 
#include <LiquidCrystal_I2C.h>

// Set the LCD address to 0x27 for a 16 chars and 2 line display
LiquidCrystal_I2C lcd(0x27, 16, 2);
// ======= END of  LCD1602 with i2C settings
void setup() {
    //Robojax.com ACS758 Current Sensor 
    pinMode(relayPin,OUTPUT);// set relayPin as output
    Serial.begin(9600);// initialize serial monitor
    Serial.println("Robojax Tutorial");
    Serial.println("ACS758 Current Sensor");
    Serial.println("with LCD1602 & I2C");    
    // initialize the LCD, 
    lcd.begin();   
  // Turn on the blacklight and print a message.
  lcd.backlight(); 
    lcd.clear();
  lcd.print("Robojax");
  lcd.setCursor (0,1); // go to start of 2nd line 
  lcd.print("ACS758 Current Sensor"); 
  delay(2000); 
  lcd.clear();  
}

void loop() {
  //Robojax code ACS758 with LCD1602 and I2C
  float voltage_raw =   (5.0 / 1023.0)* analogRead(VIN);// Read the voltage from sensor
  voltage =  voltage_raw - QOV + 0.007 ;// 0.007 is a value to make voltage zero when there is no current
  float current = voltage / FACTOR;
  if( current >= minCurrent){
     if(current <= maxCurrent)
     {
              Serial.print("Current Limit: ");
              Serial.print(maxCurrent,3);// print voltage with 3 decimal places
              Serial.print("A, I: ");
              Serial.print(current,2); // print the current with 2 decimal places
              Serial.println("A");
              //start of loop Robojax code ACS758 with LCD1602 and I2C
              lcd.clear();
              lcd.setCursor (0,0); // set to line 1, char 0  
              lcd.print("Current: ");
              lcd.setCursor (9,0); // go to start of 2nd line
              lcd.print(current);
              lcd.setCursor (15,0); // go to start of 2nd line
              lcd.print("A");
            
              lcd.setCursor (0,1);    
              lcd.print("I Limit: ");
              lcd.setCursor (9,1); // go to start of 2nd line
              lcd.print(maxCurrent);
              lcd.setCursor (15,1); // go to start of 2nd line
              lcd.print("A");   
              lcd.backlight();
             //end of loopcode Robojax code ACS758 with LCD1602 and I2C

              digitalWrite(relayPin,LOW);// turn the relay OFF to allow the current.
     }else{
      // the lines bellow will execute if current reaches above the maxCurrent value
              digitalWrite(relayPin,HIGH);// turn the relay ON to disconnect the current.
              
              Serial.print("Max Reached:");
              Serial.print(maxCurrent,3);// print the maxCurrent
              Serial.println("A");              
              Serial.print("Disconnected ");

              //start of loop Robojax code ACS758 with LCD1602 and I2C
              lcd.clear();
              lcd.setCursor (0,0); // set to line 1, char 0  
              lcd.print("I Max: ");
              lcd.setCursor (8,0); // go to start of 2nd line
              lcd.print(maxCurrent);
              lcd.setCursor (15,0); // go to start of 2nd line
              lcd.print("A");
            
              lcd.setCursor (0,1);    
              lcd.print("Disconnected");    
              lcd.backlight();
             //end of loopcode Robojax code ACS758 with LCD1602 and I2C 
             delay(maxCurrentWait );// wait for maxCurrentWait  seconds     
     }
    
  }else{
    Serial.println("No Current");
  lcd.clear();    
  lcd.setCursor (0,0);    
  lcd.print("No Current");
  digitalWrite(relayPin,LOW);// turn the relay OFF to allow the current.
          
  }
  delay(500);
}