Other Arduino Codes and Videos by Robojax
This code is to measure current using Allegro ACS758 Current Sensor and display it on LCD1602 I2C Screen and disconnect the load when the current limit reached.
In order to use this code, you must watch the following two videos and get required library and codes
Please watch latest video with Robojax ACS library Here
/*
*
* Arduino Sketch for Allegro ACS758 Current Sensor with LCD1602 & I2C module and current protection
* this sensor can measure current at range of up to 200A. It has overcurrent protection with relay to disconnect the load if
* the current reaches beyond the limit.
* It operates with 3.3 or 5V
* This video 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-Allegrao 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 watch detailed video on ACS758 Current sensor A 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
sensitivity array is holding the sensitivy 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 factor for VCC that appears at output
* when the current is zero.
* for Bidirectional sensor it is 0.5 x VCC
* for Unidirectional sensor 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);
} 
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