How to Interface With 5kg Balance Module or Load Cell

This tutorial is gonna teach you some basics on using 5kg balance module or load cell.

Step 1: Introduction

Description:

This 5kg balance module is a weight sensor module which can be used to measure the weight of object. It comes with HX711 ADC tiny controller board which eases the communication between the load cell and microcontroller. It is quite easy to use since it is capable of interfacing with Arduino. The maximum weight it can measure is 5kg. And also, it comes with a standard weight load which is used in calibration.

Specifications:

• Voltage: 5VDC
• Diameter: 10cm
• Height: 3.5cm
• Max. Load: 5kg

Step 2: Pin Definition of HX711 ADC Module

Specifications of HX711 ADC Module:

• Differential Input Voltage: ±40mV (Full-scale differential input voltage is ±40mV)
• Data Accuracy: 24 bit (24 bit analog-to-digital converter chip)
• Refresh Frequency: 10/80 Hz
• Operating Voltage: 2.7V to 5VDC
• Operating Current: <10mA

Step 3: Sample Hardware Installation

The above hardware installation is just for reference. You can connect the components according to your pin assignments in your Arduino source code.

Step 4: Sample Source Code

In the attachment section, there are altogether three files being uploaded.

File Name: HX711.zip

• Kindly download the library attached below for your own use.

File Name: calibration.zip

• In order to get the accurate reading, you will have to know the calibration factor. Firstly, setup your scale and start the sketch without a weight on the scale. Once readings are displayed, place the weight on the scale. Press 'a' or 'z' to adjust the calibration factor until the output readings match the known weight. 'a' is to increase the calibration factor whereas 'z' is to decrease the calibration factor.
• A video is uploaded to show the steps of calibrating the calibration factor.

File Name: single_hx711.zip

• After the calibration is done, upload the file named single_hx711 into your Arduino. Now, your load cell is able to measure the weight.

Step 5: Ways to Open Serial Monitor

Step 6: Result

Place anything onto the load cell and Now you are ready to measure anything. Remember do not place anything that exceeds a weight of 5kg.

Step 7: Additional Sample Source Code

Here in this part, an additional sample source code is attached. This sample source is applicable when more HX711 ADC module is connected to one Arduino board.

Comments

[piyalibedagkar02]

What can be approx calibration factor for 150 kg load cell?

[rousseyfanny]

Hi ! Thank you for this tutorial which helped me a lot. Here is my question: the code used allows to display directly the output data in weight. Is it possible to display the output voltage of the wheatstone bridge (S+ - S-) and then measure a resistance change instead of the weight change?

[stevebrown2222]

I can't get your .ino files to pass the Verify in Arduino 1.8.13. Error: No matching function for call to HX711::HX711(const unit8_t8, const unit8_t8) plus several others. I get the same type errors on all three: HX711.ino, calibration.ino, and single_hx711.ino. I am using an Arduino Mega. They will not upload either. What can I do to fix the problems? Also, how do you open a .rar file?

[wanamaa]

Why do you do the calibration using pins 5 and 6, then on your scale program you use pins 2 and 3? Wouldn't it make more sense to have the pins be the same for consistency?

[SalahO4]

when I upload the calibration program I do not get

[dieGattona]

Thank you very much for the great tutorial! With your really nice library and instructions how to calibrate I could make my own weight sensor with a luggage scale! https://www.instructables.com/id/Get-a-Hanging-Weight-Sensor-for-Your-Arduino-Proje/
I refer to your Instructable :)

[lina mohammed]

can you help me please