HX711 Weighing Sensor Module – 24-Bit ADC for Load Cells/Pressure Sensors (Large PCB)

Description

The HX711 Weighing Sensor Module is a precision 24-bit analog-to-digital converter (ADC) designed specifically for weighing scales and industrial control applications. It interfaces directly with bridge sensors such as load cells, strain gauges, and pressure sensors, converting the tiny millivolt-level analog output into a high-resolution digital signal for microcontrollers .

The module is built around the Avia Semiconductor HX711 IC, which integrates a low-noise programmable gain amplifier (PGA), an on-chip oscillator, and a regulated power supply for the load cell. The PGA offers selectable gains of 32, 64, and 128, allowing adaptation to different load cell sensitivities . The board communicates with a host microcontroller via a simple two-wire interface (DAT and CLK), requiring no special protocol or library for basic operation .

The “Large PCB” variant typically provides a larger terminal block for easier load cell wiring and may include additional mounting holes. The module supports selectable 10Hz or 80Hz output data rates, with 10Hz offering better noise rejection for stable readings and 80Hz suitable for faster, dynamic measurements . It operates from a 2.7V to 5.5V supply and draws less than 1.5mA during normal operation .

Critical limitations: The HX711 is an ADC, not a complete scale. It requires a load cell (separate component) and calibration to convert raw readings to meaningful weight units. Power supply noise directly affects measurement stability—a clean, regulated supply is essential . The module is not waterproof and should be protected from moisture and mechanical stress. For 3.3V logic systems, connect VCC to 5V (for the load cell) and VDD to 3.3V (for logic level) .

Features

• 24-Bit High-Resolution ADC: Designed specifically for weigh scales and bridge sensors .

• Selectable Gain (32/64/128): On-chip low-noise PGA adapts to different load cell sensitivities .

• Two-Wire Interface: Simple DAT and CLK connection to any microcontroller GPIO .

• Selectable Output Data Rate: 10Hz (stable) or 80Hz (faster) via onboard jumper .

• On-Chip Regulator: Provides clean power for the load cell and ADC analog supply .

• Simultaneous 50/60Hz Rejection: Reduces mains interference for stable readings .

• Wide Supply Range (2.7V–5.5V): Compatible with both 3.3V and 5V systems .

• Large PCB with Terminal Block: Easier wiring and secure connections for load cells.

Technical Specifications