# 5kg load cell with HX711 amplifier is not working

**URL:** <https://forum.arduino.cc/t/5kg-load-cell-with-hx711-amplifier-is-not-working/1293794>\
**Category:** General Guidance\
**Created:** [August 20, 2024, 8:09pm UTC](https://forum.arduino.cc/t/5kg-load-cell-with-hx711-amplifier-is-not-working/1293794 "2024-08-20T20:09:47Z")\
**Posts on this page:** 8\
**Page:** 1

<div class="post-metadata">

**Author:** ![daanscale](https://dub1.discourse-cdn.com/arduino/user_avatar/forum.arduino.cc/daanscale/32/1007716_2.png) [@daanscale](https://forum.arduino.cc/u/daanscale)\
**Post date:** [August 20, 2024, 8:09pm UTC](https://forum.arduino.cc/t/5kg-load-cell-with-hx711-amplifier-is-not-working/1293794/1 "2024-08-20T20:09:47Z")

</div>

Hello everyone,

I am trying to make a scale with a 5kg load cell and a HX711 amplifier. I have added pictures to this post of how I connected it. The problem is that my readings are not varying with different weights being put on the load cell. I am only getting readings around 1750 in the serial monitor.

Does anyone know what I am doing wrong? Thank you in advance!

Kind regards,  
Daan

This is the code that I am using to test:

```arduino
//Defining scale 
#include "HX711.h"

#define LoadcellDOUT 4
#define LoadcellSCK 5

HX711 scale; 

void setup() {
  Serial.begin(57600);

  scale.begin(LoadcellDOUT, LoadcellSCK);

}

void loop() {
 //Serial.println(scale.read_average(5));
 Serial.println(scale.read());

 delay(200);

}

```

Connections from HX711:

DAT --\> pin 4  
CLK --\> 5  
VCC --\> 5V  
GND --\> GND

 ![Picture1](https://europe1.discourse-cdn.com/arduino/original/4X/f/2/e/f2ea7ea49116c65b22ab7e3d819862bac630a4b9.jpeg)  
 ![Picture2](https://europe1.discourse-cdn.com/arduino/original/4X/f/a/0/fa0aa1e03dbf7d3e77cce2d4cb1e9aa552ad5e8e.jpeg)  
 ![Picture3](https://europe1.discourse-cdn.com/arduino/original/4X/7/5/d/75d972433e97db657267d4366174e47d7eccb14b.jpeg)

---

<div class="post-metadata">

**Author:** ![davidefa](https://dub1.discourse-cdn.com/arduino/user_avatar/forum.arduino.cc/davidefa/32/1088935_2.png) [@davidefa](https://forum.arduino.cc/u/davidefa)\
**Post date:** [August 20, 2024, 8:18pm UTC](https://forum.arduino.cc/t/5kg-load-cell-with-hx711-amplifier-is-not-working/1293794/2 "2024-08-20T20:18:14Z")

</div>

Where is your load cell, how is mechanically connected? Is the measured weight never correct?

P.S.  
Also follew the examples included in the library

---

<div class="post-metadata">

**Author:** ![sonofcy](https://dub1.discourse-cdn.com/arduino/user_avatar/forum.arduino.cc/sonofcy/32/1283617_2.png) [@sonofcy](https://forum.arduino.cc/u/sonofcy)\
**Post date:** [August 20, 2024, 8:48pm UTC](https://forum.arduino.cc/t/5kg-load-cell-with-hx711-amplifier-is-not-working/1293794/3 "2024-08-20T20:48:29Z")

</div>

Half the needed code is missing. Use the examples, it is not as intuitive as you think. Also check the SparkFun version of the software for a couple of more ideas. You will need to read the HX711 library code for a total understanding.

---

<div class="post-metadata">

**Author:** ![gilshultz](https://avatars.discourse-cdn.com/v4/letter/g/67e7ee/32.png) [@gilshultz](https://forum.arduino.cc/u/gilshultz)\
**Post date:** [August 20, 2024, 10:22pm UTC](https://forum.arduino.cc/t/5kg-load-cell-with-hx711-amplifier-is-not-working/1293794/4 "2024-08-20T22:22:50Z")

</div>

Your pictures although nice do not help me much. Post an annotated schematic showing all connections. Also post links to each hardware item.

---

<div class="post-metadata">

**Author:** ![daanscale](https://dub1.discourse-cdn.com/arduino/user_avatar/forum.arduino.cc/daanscale/32/1007716_2.png) [@daanscale](https://forum.arduino.cc/u/daanscale)\
**Post date:** [August 21, 2024, 12:08pm UTC](https://forum.arduino.cc/t/5kg-load-cell-with-hx711-amplifier-is-not-working/1293794/5 "2024-08-21T12:08:50Z")

</div>

Alright, I have not yet mechanically connected the loadcell to a proper setup because I first wanted to see if the load cell would give me any proper readings. I am putting one end of the load cell on the edge of my desk and I am pressing with my hand on the other end to see if the readings are changing, but they are not.

The link below is the HX711 module I am using. Does anyone know what the little pad on the backside is that says "RATE"?  
[https://nl.aliexpress.com/item/1005006293368575.html?spm=a2g0o.productlist.main.5.7faapxvMpxvMOy&algo\_pvid=041bc3ad-5197-4455-b86f-a265593fa810&algo\_exp\_id=041bc3ad-5197-4455-b86f-a265593fa810-2&pdp\_npi=4%40dis!EUR!1.75!1.12!!!13.56!8.68!%402103894417242397623206870e6b48!12000036639761167!sea!NL!810974822!X&curPageLogUid=Lm7NhsRldqMt&utparam-url=scene%3Asearch|query\_from%3A](https://nl.aliexpress.com/item/1005006293368575.html?spm=a2g0o.productlist.main.5.7faapxvMpxvMOy&algo_pvid=041bc3ad-5197-4455-b86f-a265593fa810&algo_exp_id=041bc3ad-5197-4455-b86f-a265593fa810-2&pdp_npi=4%40dis%21EUR%211.75%211.12%21%21%2113.56%218.68%21%402103894417242397623206870e6b48%2112000036639761167%21sea%21NL%21810974822%21X&curPageLogUid=Lm7NhsRldqMt&utparam-url=scene%3Asearch%7Cquery_from%3A)

5kg load cell:  
[https://nl.aliexpress.com/item/1005006827930173.html?spm=a2g0o.productlist.main.1.3b86688aNKO5Sl&algo\_pvid=bb37aa0c-7f1a-4b4e-a53e-82b7d6cef7cc&algo\_exp\_id=bb37aa0c-7f1a-4b4e-a53e-82b7d6cef7cc-0&pdp\_npi=4%40dis!EUR!2.99!1.94!!!23.11!15.02!%4021039cba17242419115832633e2d10!12000038432362683!sea!NL!810974822!X&curPageLogUid=tp6gS3wXYiX8&utparam-url=scene%3Asearch|query\_from%3A](https://nl.aliexpress.com/item/1005006827930173.html?spm=a2g0o.productlist.main.1.3b86688aNKO5Sl&algo_pvid=bb37aa0c-7f1a-4b4e-a53e-82b7d6cef7cc&algo_exp_id=bb37aa0c-7f1a-4b4e-a53e-82b7d6cef7cc-0&pdp_npi=4%40dis%21EUR%212.99%211.94%21%21%2123.11%2115.02%21%4021039cba17242419115832633e2d10%2112000038432362683%21sea%21NL%21810974822%21X&curPageLogUid=tp6gS3wXYiX8&utparam-url=scene%3Asearch%7Cquery_from%3A)

I have now tested the load cell with the following two codes I found at this link:

> **[Arduino Scale With 5kg Load Cell and HX711 Amplifier](https://www.instructables.com/Arduino-Scale-With-5kg-Load-Cell-and-HX711-Amplifi/)**
>
> Arduino Scale With 5kg Load Cell and HX711 Amplifier: This Instructable describes how to make a small weighing scale using readily available off the shelf parts.
> 
> Materials needed:
> 
> 1. Arduino - this design uses a standard Arduino Uno, other Arduino...

```arduino
#include "HX711.h"

#define LOADCELL_DOUT_PIN 3
#define LOADCELL_SCK_PIN 2

HX711 scale;

float calibration_factor = -7050; //-7050 worked for my 440lb max scale setup

void setup() {
  Serial.begin(9600);
  Serial.println("HX711 calibration sketch");
  Serial.println("Remove all weight from scale");
  Serial.println("After readings begin, place known weight on scale");
  Serial.println("Press + or a to increase calibration factor");
  Serial.println("Press - or z to decrease calibration factor");
  
  scale.begin(LOADCELL_DOUT_PIN, LOADCELL_SCK_PIN);
  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);
}

void loop() {

  scale.set_scale(calibration_factor); //Adjust to this calibration factor
  Serial.print("Reading: ");
  Serial.print(scale.get_units(), 1);
  Serial.print(" lbs"); //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;
  }
}

```

```arduino
#include "HX711.h"

#define calibration_factor -7050.0 //This value is obtained using the SparkFun_HX711_Calibration sketch

#define LOADCELL_DOUT_PIN 3
#define LOADCELL_SCK_PIN 2

HX711 scale;

void setup() {
  Serial.begin(9600);
  Serial.println("HX711 scale demo");

  scale.begin(LOADCELL_DOUT_PIN, LOADCELL_SCK_PIN);
  scale.set_scale(calibration_factor); //This value is obtained by using the SparkFun_HX711_Calibration sketch
  scale.tare(); //Assuming there is no weight on the scale at start up, reset the scale to 0

  Serial.println("Readings:");
}

void loop() {
  Serial.print("Reading: ");
  Serial.print(scale.get_units(), 1); //scale.get_units() returns a float
  Serial.print(" lbs"); //You can change this to kg but you'll need to refactor the calibration_factor
  Serial.println();
}

```

No matter what I do, the result looks like this:

 ![image](https://europe1.discourse-cdn.com/arduino/original/4X/0/1/8/018756b0f422a4bf7f98bb68f73134f186b45d57.png)

In the screenshot below you can see all of the connections:

 ![image](https://europe1.discourse-cdn.com/arduino/original/4X/9/5/a/95ab9b2b23ad6ce32e9f15e43571005a87f78217.png)

---

<div class="post-metadata">

**Author:** ![aliarifat794](https://avatars.discourse-cdn.com/v4/letter/a/eb8c5e/32.png) [@aliarifat794](https://forum.arduino.cc/u/aliarifat794)\
**Post date:** [August 21, 2024, 12:12pm UTC](https://forum.arduino.cc/t/5kg-load-cell-with-hx711-amplifier-is-not-working/1293794/6 "2024-08-21T12:12:51Z")

</div>

You can get the full code and detailed circuit diagram here:

> **[Electronic scale with Arduino with HX711 module and tare function - Share...](https://www.pcbway.com/project/shareproject/Electronic_scale_with_Arduino_with_HX711_module_and_tare_function_40b65139.html)**
>
> More info and updates in https://rogerbit.com/wprb/2024/03/balanza-electronica/In this tutorial, you will learn step by step how to use an HX711 module with a load cell to make accurate weight measure...

In this tutorial, It is shown step by step how to use an HX711 module with a load cell to make accurate weight measurements using an Arduino.

---

<div class="post-metadata">

**Author:** ![daanscale](https://dub1.discourse-cdn.com/arduino/user_avatar/forum.arduino.cc/daanscale/32/1007716_2.png) [@daanscale](https://forum.arduino.cc/u/daanscale)\
**Post date:** [August 21, 2024, 12:46pm UTC](https://forum.arduino.cc/t/5kg-load-cell-with-hx711-amplifier-is-not-working/1293794/7 "2024-08-21T12:46:05Z")

</div>

I guess I solved the problem. I took a closer look at the connections to the strain gauges on the load cell and 2 of the tiny wires were broken. I soldered them back together and now it seems like it is working.

---

<div class="post-metadata">

**Author:** ![system](https://dub1.discourse-cdn.com/arduino/user_avatar/forum.arduino.cc/system/32/1140315_2.png) [@system](https://forum.arduino.cc/u/system)\
**Post date:** [February 17, 2025, 12:46pm UTC](https://forum.arduino.cc/t/5kg-load-cell-with-hx711-amplifier-is-not-working/1293794/8 "2025-02-17T12:46:41Z")

</div>

Closed on February 17, 2025, 12:46pm UTC

This topic was automatically closed 180 days after the last reply. New replies are no longer allowed.