Have you ever heard of HX711 Bit ADC? HX711 is often used in conjunction with load cells to create weighing scales. We can find it in our daily life. Besides, with its multiple functions and outstanding features, it is favored by all walks of life such as industrial engineering, medicine, science, and technology. In this post, we will explore what HX711 HX711–24 Bit ADC and load cells, are and how can we use them in different fields. 

Understanding load cells: why HX711 is Important?

A load cell is a transducer or sensor that converts a force or load acting on it into an electronic signal. This signal can then be measured, recorded, or used to control various processes. Load cells are used in a wide range of applications where measuring force or weight is crucial. The HX711 acts as a bridge between the analog world (load cell) and the digital world (microcontroller). It ensures that the small analog signal from the load cell is amplified and accurately converted into a digital value that can be used for further processing. Therefore, HX711 always works together with load cells and holds a necessary place. Then, the following sections will explore HX711.

What is HX711?

The HX711 is a precision analog-to-digital converter (ADC) designed for weigh scales and industrial control applications to interface directly with a bridge sensor. It is specifically tailored for weighing scales and applications where high accuracy is required. HX711 ADC is popular in all kinds of fields. But why HX711 is an essential component in a myriad of devices, notably electronic scales?

HX711 Pinout

Figure1-pinout

HX711 Pin Configuration

There are 16 pins on HX711. The chip has a number of packages; select one based on your needs. Below is a description for each pin.

Main Features of HX711

One of the most effective features is that HX711 possesses precision and the capability to accurately measure very small changes in electrical resistance. What is more, there are other key aspects  that contribute to its popularity:

• High Resolution: This means it can provide a very high level of precision in its measurements and resolve small changes in voltage, allowing for highly accurate weight measurements.
• Differential Input: The HX711 has a differential input, which can measure the voltage difference between two input terminals. This is crucial for working with load cells, which typically output a small differential voltage signal.
• Built-In Amplification: The HX711 has a built-in amplifier with adjustable gain. This is essential for amplifying the small signal from the load cell, which might be in the millivolt range, to a level that can be accurately digitized.
• Zero Drift: The HX711 is designed to low offset and gain drift. It maintains its accuracy over time, even as environmental conditions change (e.g., temperature variations).
• Tare Functionality: The HX711 often includes a tare function. This allows you to zero out any initial weight (like the weight of a container) so that you're only measuring the net weight.
• Digital Interface: It communicates with a microcontroller using a digital interface (like SPI or I2C), which makes it easy to integrate into various projects.
• Low Noise: The HX711 is designed to be relatively immune to electromagnetic interference and other sources of noise, ensuring that the signal it reads from the load cell is as clean and accurate as possible.
• Cost-Efficient: It's a relatively low-cost component for the level of precision and functionality it provides. This makes it widely accessible for hobbyists, students, and professionals alike.

Common Applications of HX711

The HX711 is commonly used in applications where precise weight measurements are required. This part will introduce HX711 in weight scalls and other common applications.

HX711 in Digital Scales

The HX711 is frequently used in digital weighing scales, from small kitchen to industrial floor scales.

Load Cell Amplifier

Have you ever been curious about load cells? The HX711 is often used as an amplifier for load cells. It amplifies the small analog voltage output of the load cell to a level that can be accurately measured by a microcontroller.

Weighing Systems

It's used in various weighing systems for industrial and commercial purposes, such as the conveyor belt for checking luggage at the airport., packaging machines, and filling machines. These systems need accurate weight measurements for processes like packaging and quality control. Have you ever thought about the principle of these weighing systems?

Other HX711 Applications

In addition to the applications mentioned above, HX711 is also applied in Force Measurement, Smart Agriculture, Automated Dispensing Systems, Medical and Health Monitoring, Vehicle Weighing

HX711 works with Arduino

In the above section, we have explored key features and common applications of HX711. HX711 Amplifier always works together with Arduino and load cells to create a digital scale. In this section, we will introduce basic steps to use the HX711 with an Arduino.

Step1: Wiring HX711 pinout on Arduino

Connect the VCC pin of the HX711 to the 5V output on your Arduino. GND pin can connect the ground (GND) pin on your Arduino. DT (data) pin of the HX711 to a digital pin on your Arduino. Connect the SCK (clock) pin of the HX711 to another digital pin on your Arduino.

Figure2-Wiring HX711 pinout on Arduino

Step2 Installing Library:

You will need to install the HX711 library in your Arduino IDE. This library simplifies communication with the HX711 module.

Step2: Programming the HX711

Figure3-Programming the HX711

Make sure to replace DT and SCK with the actual PINs you've used for data and clock.

Power Supply Considerations:

Depending on your application, you might need an external power supply for the HX711 module if the load cells draw too much current for the Arduino's 5V pin.

Remember to handle the load cells carefully and make sure they are correctly calibrated for accurate readings. Calibration instructions are usually provided by the manufacturer of the load cells you're using.

 HX711 PDF

HX711 Datasheet