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

Description

The HX711 Weighing Sensor Module (Mini PCB) 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 Mini PCB variant provides the same HX711 functionality as the larger board but in a more compact footprint, making it suitable for space-constrained projects and portable scale designs. 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, with Channel A supporting gain 64/128 and Channel B fixed at gain 32 . The board communicates via a simple two-wire interface (DAT and CLK), requiring no special protocol for basic operation .

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 2.6V 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 with proper decoupling capacitors is essential . For 3.3V logic systems, connect VCC to 5V (for load cell excitation) and VDD to 3.3V (for logic level) if the module has separate pins. The Mini PCB may have limited terminal block space for load cell wiring compared to the Large PCB variant.

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) .

• 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 (2.6V–5.5V): Compatible with both 3.3V and 5V systems .

• Compact Mini PCB: Smaller footprint for space-constrained designs.

Technical Specifications