ARDUINO LOAD CELL 50 KG

First, you must using 4 load cell 50 kg for balance
please watch this tutorial

first do the calibration

=================================================================

#include "HX711.h"  //You must have this library in your arduino library folder ,search in github

#define DOUT  3

#define CLK  2

HX711 scale(DOUT, CLK);

//Change this calibration factor as per your load cell once it is found you many need to vary it in thousands

//float calibration_factor = -96650; //-106600 worked for my 40Kg max scale setup 

 float calibration_factor = 190; 

//=============================================================================================

//                         SETUP

//=============================================================================================

void setup() {

  Serial.begin(9600);

  Serial.println("HX711 Calibration");

  Serial.println("Remove all weight from scale");

  Serial.println("After readings begin, place known weight on scale");

  Serial.println("Press a,s,d,f to increase calibration factor by 10,100,1000,10000 respectively");

  Serial.println("Press z,x,c,v to decrease calibration factor by 10,100,1000,10000 respectively");

  Serial.println("Press t for tare");

  scale.set_scale();

  scale.tare(); //Reset the scale to 0

  long zero_factor = scale.read_average(); //Get a baseline reading

  Serial.print("Zero factor: "); //This can be used to remove the need to tare the scale. Useful in permanent scale projects.

  Serial.println(zero_factor);

}

//=============================================================================================

//                         LOOP

//=============================================================================================

void loop() {

  scale.set_scale(calibration_factor); //Adjust to this calibration factor

  Serial.print("Reading: ");

  Serial.print(0.453592 * scale.get_units(), 3);

  Serial.print(" kg"); //Change this to kg and re-adjust the calibration factor if you follow SI units like a sane person

  Serial.print(" calibration_factor: ");

  Serial.print(calibration_factor);

  Serial.println();

  if(Serial.available())

  {

    char temp = Serial.read();

    if(temp == '+' || temp == 'a')

      calibration_factor += 10;

    else if(temp == '-' || temp == 'z')

      calibration_factor -= 10;

    else if(temp == 's')

      calibration_factor += 100;  

    else if(temp == 'x')

      calibration_factor -= 100;  

    else if(temp == 'd')

      calibration_factor += 1000;  

    else if(temp == 'c')

      calibration_factor -= 1000;

    else if(temp == 'f')

      calibration_factor += 10000;  

    else if(temp == 'v')

      calibration_factor -= 10000;  

    else if(temp == 't')

      scale.tare();  //Reset the scale to zero

  }

}

=============================================================

load cell in action :

#include "HX711.h"  //You must have this library in your arduino library folder

#define DOUT  3

#define CLK  2

HX711 scale(DOUT, CLK);

//Change this calibration factor as per your load cell once it is found you many need to vary it in thousands

float calibration_factor = 230; //-106600 worked for my 40Kg max scale setup 

double a;

//=============================================================================================

//                         SETUP

//=============================================================================================

void setup() {

  Serial.begin(9600);  

  Serial.println("Press T to tare");

  scale.set_scale(calibration_factor);  //Calibration Factor obtained from first sketch

 // scale.tare();             //Reset the scale to 0  

}

//=============================================================================================

//                         LOOP

//=============================================================================================

void loop() {

  Serial.print("Weight: ");

  Serial.print((0.453592 * scale.get_units(3))/10, 1);  //Up to 3 decimal points

  Serial.println(" kg"); //Change this to kg and re-adjust the calibration factor if you follow lbs

  float a = ((0.453592 * scale.get_units(3))/10);

  Serial.println(a,1);

  if(a,1 >= 0.8){

    Serial.println("stop");

  }

  if(Serial.available())

  {

    char temp = Serial.read();

    if(temp == 't' || temp == 'T'){

      scale.tare();  //Reset the scale to zero }

    }

    if(temp == 'a'){

      scale.set_scale(calibration_factor);

      scale.tare();

    }

  }

}