HX711 24-Bit Precision Dual-Channel Module For Load Cell

HX711 24-Bit Precision Dual-Channel Module For Load Cell is an ultra-high-precision 24-bit analog-to-digital converter (ADC) module engineered specifically for weigh scales, industrial pressure transducers, and microvolt-level bridge sensor amplification. Featuring an internal low-noise programmable gain amplifier (PGA) with selectable gain factors of 64 or 128 on Channel A and a fixed gain of 32 on Channel B, this board directly amplifies minute millivolt differential signals from full Wheatstone bridge load cells. Furthermore, the module features an integrated low-noise on-chip power supply regulator that delivers dedicated, stable analog excitation voltage to external load cells, eliminating measurement drift caused by digital noise. Consequently, this module uses a simple two-wire digital serial interface (PD_SCK and DOUT) compatible with any microcontroller I/O pin without requiring internal hardware SPI or I2C peripheral blocks.

Key Features:

• High-Resolution 24-Bit Sigma-Delta ADC: Delivers true 24-bit conversion resolution for microvolt-level load cell telemetry.
• On-Chip Low-Noise PGA: Programmable gain of 64 or 128 accepts ±20mV or ±40mV full-scale differential bridge signals.
• Dual Differential Input Channels: Channel A supports precision weighing bridge inputs; Channel B supports secondary sensor monitoring.
• Onboard Analog Power Regulator: Provides ultra-clean analog excitation potential, isolating bridge sensors from noisy digital rails.
• Simple 2-Wire Serial Interface: Communicates via clock (PD_SCK) and data (DOUT) lines compatible with any microcontroller GPIO.

Technical Specifications:

• Operating Voltage: 2.6V to 5.5V DC (5.0V recommended for optimal load cell excitation)
• Operating Current: 1.6mA (active normal mode), < 1µA (hardware power-down mode)
• ADC Resolution: 24-Bit Sigma-Delta
• Selectable Gain: 64 or 128 (Channel A), 32 (Channel B)
• Output Data Rate: 10 Samples/sec (SPS) or 80 Samples/sec (selectable via pin)
• Simultaneous 50Hz and 60Hz Rejection: Built-in power supply noise rejection filter
• Differential Input Voltage: ±20mV (Gain = 128) / ±40mV (Gain = 64)
• Operating Temperature Range: -40°C to +85°C

Mechanical Specifications:

• PCB Material: FR-4 Industrial Flame Retardant Glass Epoxy PCB
• Terminal Headers: 4-pin load cell interface header (E+, E-, A-, A+) and 4-pin MCU logic header (VCC, DOUT, SCK, GND)
• Header Pitch: Standard 2.54mm (0.1 inch) nominal pin pitch
• Decoupling: Dual ceramic bypass filtering capacitors on analog and digital domains

Dimensions:

• Length: 34.0mm
• Width: 20.5mm
• Height: 3.5mm (excluding pin header)
• Module Weight: ≈ 3.0g

Pinout and Wiring:

• E+ (Red): Positive excitation voltage output to load cell.
• E- (Black): Negative excitation / ground reference to load cell.
• A- (White): Negative differential signal input from load cell.
• A+ (Green): Positive differential signal input from load cell.
• VCC: Digital power supply input (+2.6V to +5.5V DC from MCU).
• DOUT: Serial data output line to microcontroller GPIO.
• PD_SCK: Serial clock input and power-down control line from microcontroller.
• GND: Digital ground reference (0V).

Datasheet Reference:

• Consult internal register architecture, timing protocols, and calibration formulas in the View Avia Semiconductor HX711 24-Bit ADC Datasheet PDF.

Commonly Used in:

• Precision Gram Scales: Interfacing 4-wire strain load cells with microcontrollers to achieve 0.01g resolution.
• Industrial Platform Checkweighers: Digitizing microvolt bridge signals on conveyor packaging systems.
• IoT Agricultural Telemetry: Remote beehive mass logging and livestock feed hopper monitoring.

Applications:

• Digital Gram Weigh Scale: Pairing with an aluminum load cell to measure weight with 0.1g or 0.01g resolution on an Arduino OLED screen.
• Smart Beehive Monitoring: Continuously tracking honey production and hive colony mass remotely over LoRa or cellular networks.
• Industrial Silo Level: Measuring total structural weight of feed hoppers to prevent material runout.

Equivalent Models:

• ADS1232 24-Bit Bridge ADC: Texas Instruments ultra-low noise 24-bit delta-sigma ADC with onboard temperature sensor and 19.2-bit effective ENOB.
• INA125 Instrumentation Amplifier: Analog Burr-Brown precision instrumentation amplifier with integrated precision voltage reference generator.
• CS1237 24-Bit Weighing ADC: High-performance single-chip 24-bit ADC alternative with internal oscillator and two-wire bus interface.

Package Includes:

• 1 × HX711 24-Bit Precision Dual-Channel Module For Load Cell
• 1 × 10-Pin 2.54mm Straight Pin Header Strip