Introduction: Tutorial to Interface HX711 With Load Cell Straight Bar 50kg



This module uses 24 high-precision A / D converter. This chip is designed for high-precision electronic scale and design, has two analog input channels, programmable gain of 128 integrated amplifier. The input circuit can be configured to provide a bridge voltage electrical bridge (such as pressure, load) sensor model is an ideal high-precision, low-cost sampling front-end module.


- Two selectable differential input channels

- On-chip power supply regulator for load-cell and ADC analog power supply

- On-chip oscillator requiring no external component with optional external crystal

- On-chip power-on-reset

- Data Accuracy: 24 bit (24 bit analog-to-digital converter chip)

- Refresh Frequency: 10/80 Hz

- Operation supply voltage range: 4.8 ~ 5.5V

- Operation supply Current: 1.6mA

- Operation temperature range: -20 ~ +85℃

- Demension: Approx. 36mm x 21mm x 4mm / 1.42" x 0.83" x 0.16"



A low-cost half-bridge load cell with a full-scale sensitivity of 1.1 mV / V with a maximum measuring weight of 50 kg. The maximum load the sensor can withstand is 50 Kg. If you combine two of them in a measurement of 50Kg or more, a full-bridge configuration can be used for more accurate weighing. You can also use a combination of four.


- Capacity : 50kgTotal

- Size: 34 x 34 x 3mm

- Cable Length: 40cm

- Material: Aluminium Alloy

- Weight: 18g

Step 1: Material Preparation

In this tutorial, you will need :

1. Arduino Uno Board and USB

2. HX711 Balance Sensor Module

3. Load Cell Straight Bar 50kg

4. Male to Female Jumpers

5. Arduino IDE

6. 1K OHM resistor (2pcs)

Step 2: Hardware Installation

Step 3: HX711 Library

This tutorial need a hx711 library. For the attachment section, hx711 library is being uploaded.

Kindly download the library and add .Zip library to your Arduino IDE.

step 1 - click Sketch

step 2 - click Include Library

step 3 - click add .Zip Library

step 4 - select the .zip file you have downloaded

Step 4: Connect Arduino to PC

Connect arduino uno which is ready to connect with hx711 and load cell using usb.

Step 5: Sample Source Code

Download the sample source code below, open and upload this sample source code into your Arduino IDE.

NOTE : You can change your calibration factor before uploading the code OR you can adjust it later in the serial monitor box since the code allow you to add and substract the value of calibration factor.

Step 6: Open Sample Source Code

First, you need to extract the zip file. right click the zip file and then click extract here. Second, open the HX711_code file and open the sample source code.

Step 7: Upload the Code to Arduino UNO

Before upload the code, you need to select the board is Arduino UNO and you need to make sure the com of adruino IDE and the usb port is the same com. Then, upload the sample source code.

Step 8: Serial Monitor

When you has succesfully uploaded the sample source code into your Arduino Uno Board. Open Serial Monitor and it will show u as shown in the picture above.

Step 9: Result

when the serial monitor show values, it means that the interfacing between module and load cell has successfully. Now, you can set your own calibration factor by adjusting the value using the '+' or 'a' to increase the value OR '-' or 'z' to decrease the value. You have to calibrate only once for each load cell.

NOTE : This tutorial only show you on how to interface HX711 with load cell straight bar 50kg. The calibration factor we use in sample source code is to determine the weight value for 2kg loads. You have to set your own calibration factor for your load cell. Check on this video to learn on how to set the calibration factor for load cells. Remember that each load cell with different calibration factor ie. Thus, you will have to set calibration factor for each load cell.

Step 10: Videos

This video shows how HX711 Balance Module interface with Load Cell Straight Bar 50kg