Arduino Wire Library Capacitive Load: Understanding Load Cells and HX711 Modules

Load cells are classified into different accuracy classes or grades based on their overall performance capabilities. When selecting a load cell for an application, it is essential to consider factors such as precision grade, weight specification, and compatibility with the intended use.

In this tutorial, we will focus on using a Precision Grade C2 40Kg load cell with the HX711 board. The HX711 module is a precision 24-bit analog-to-digital converter (ADC) designed for weigh scales and industrial control applications to interface directly with a bridge sensor.

The HX711 board has several connections, including E+, E-, A+, A-, and B+, B- pins. Most load cells have four wires - red, black, green, and white - which correspond to these connections. Understanding the load cell connection diagram and pinout is crucial for proper integration with the Arduino board.

Unlike other modules that require programming for internal registers, all controls on the HX711 are accessible through its pins. The on-chip power-on-reset circuitry simplifies digital interface initialization, making it easy to use. The module can also be powered by an external clock source or a crystal oscillator, eliminating the need for additional components.

The HX711 has two channels - Channel A and Channel B - which can be programmed with different gains. Channel A can be set to gain 128 or 64, corresponding to a full-scale differential input voltage of ±0mV or ±40mV respectively, when using a 5V supply. The input multiplexer selects either Channel A or B as the differential input to the low-noise programmable gain amplifier (PGA).

In this Arduino tutorial, we will demonstrate how to interface a 40Kg load cell with an Arduino board using the HX711 load cell amplifier module. This design is suitable for weighing scale applications and industrial control systems that require precision measurement.

By understanding the basics of load cells and HX711 modules, you can create accurate and reliable weighing scale designs using Arduino boards. In this article, we have explored the key concepts and provided a step-by-step guide to help you get started with your project.

Arduino wire library capacitive load