Would like help with code error for weight scale

Projects Programming
1

Good afternoon Ladies and Gentlemen,
For my high school Senior project in my Biomedical Engineering class, one of the steps for my final product is creating a weight sensor that allows me to see the weight measured on a LCD screen. I was able to find this beautifully laid out in the article *Digital Force Gauge & Weight Scale with Loadcell & Arduino * and under "Measuring the Weight of Objects" I was able to find the breadboard view of the wiring and the code.

However, when I used the code:

/* 
*  Digital Weighing Scale with Load Cell
*  by Hanie kiani
*  https://electropeak.com/learn/   
*/
#include "HX711.h"  //You must have this library in your arduino library folder
#include <LiquidCrystal.h>
LiquidCrystal lcd(12, 11, 10, 9, 8, 7);
#define DOUT  4
#define CLK  5
HX711 scale(DOUT, CLK);
float calibration_factor = 2230; // this calibration factor is adjusted according to my load cell
float units;
void setup() {
 lcd.begin(16,2);
 Serial.begin(9600);  
 Serial.println("Press T to tare");
scale.set_scale(calibration_factor); //Adjust to this calibration factor
 scale.tare(); 
}
void loop() {
units = scale.get_units(), 5;
 if (units < 0)
 {
   units = 0.00;
 }
 lcd.setCursor(0,0);
 lcd.print("Weight: ");
 lcd.setCursor(8,0);
 lcd.print(units,5); //displays the weight in 4 decimal places only for calibration
 lcd.setCursor(14,0);
 lcd.print("grams");
 if(Serial.available())
 {
   char temp = Serial.read();
   if(temp == 't' || temp == 'T')
     scale.tare();  //Reset the scale to zero      
 }
}

I got the error:

<Arduino: 1.8.13 (Windows Store 1.8.42.0) (Windows 10), Board: "Arduino Uno"

Weight_sensor_project:11:22: error: no matching function for call to 'HX711::HX711(int, int)'

HX711 scale(DOUT, CLK);

^

In file included from C:\Users\311rwv26\Documents\Arduino\Weight_sensor_project\Weight_sensor_project.ino:6:0:

C:\Users\311rwv26\Documents\Arduino\libraries\HX711\src/HX711.h:30:3: note: candidate: HX711::HX711()

HX711();

^~~~~

C:\Users\311rwv26\Documents\Arduino\libraries\HX711\src/HX711.h:30:3: note: candidate expects 0 arguments, 2 provided

C:\Users\311rwv26\Documents\Arduino\libraries\HX711\src/HX711.h:19:7: note: candidate: constexpr HX711::HX711(const HX711&)

class HX711

^~~~~

C:\Users\311rwv26\Documents\Arduino\libraries\HX711\src/HX711.h:19:7: note: candidate expects 1 argument, 2 provided

exit status 1

no matching function for call to 'HX711::HX711(int, int)'>

This report would have more information with
"Show verbose output during compilation"
option enabled in File -> Preferences.

(I apologize and please forgive me if I formatted the code and/or the error incorrectly. This is my first time posting a question, and even after reading the How to get the best out of this forum (full version) article, it is possible that I still formatted incorrectly)

I found how to fix the code in the comments of the above mentioned article, but I was confused and was hoping for some help.

Thank you for all your help!

2

Look at the example code that came with the library.

In the first such library I found on gitbub, I found this:

#include "HX711.h"

// HX711 circuit wiring
const int LOADCELL_DOUT_PIN = 2;
const int LOADCELL_SCK_PIN = 3;

HX711 scale;

void setup() {
  Serial.begin(57600);
  scale.begin(LOADCELL_DOUT_PIN, LOADCELL_SCK_PIN);
}

void loop() {

  if (scale.is_ready()) {
    long reading = scale.read();
    Serial.print("HX711 reading: ");
    Serial.println(reading);
  } else {
    Serial.println("HX711 not found.");
  }

  delay(1000);
  
}

It looks better matched to your library.

3

The HX711 library was changed back in February of 2019 to remove the constructor variant that includes arguments for the data and clock pins. You must have found code that was written before then. See the examples in the current library for the proper way to do it.

4

Thank you both! I really appreciate your help!