M5Stack Weight I2C Unit (HX711)

M5Stack HX711 Weight I2C Unit for Load-Cell Systems

The M5Stack Weight I2C Unit combines an STM32F030F4P6 controller with an HX711 24-bit ADC to connect strain-gauge load cells to an I2C host. Instead of dedicating host timing to the HX711 interface, the unit handles local acquisition and exposes weighing data through I2C at address 0x26.

This architecture is useful for compact scales, material monitoring, logistics fixtures, laboratory measurement setups, and multi-point weighing systems. Multiple devices can share an I2C bus when the complete address plan and electrical bus limits are managed correctly.

Convert Load-Cell Signals with a 24-Bit ADC

The HX711 is designed for small differential signals from bridge-type load cells. The 24-bit conversion path provides fine digital resolution, but final weighing accuracy depends on the load cell, excitation stability, mechanical structure, calibration mass, temperature drift, vibration, creep, wiring, and installation geometry.

Calibrate the Complete Mechanical Assembly

Zero the assembled system after the load cell, platform, fixtures, and cabling are installed. Use one or more known reference masses across the expected working range, then verify repeatability during loading and unloading. A high ADC bit depth does not by itself guarantee high absolute accuracy.

I2C Address 0x26 for Host Integration

The unit communicates at I2C address 0x26. Before adding multiple sensors, check address conflicts, bus pull-ups, cable length, capacitance, and power distribution. I2C is intended for local embedded connections; longer installations may require a different physical-layer strategy.

Build for Stable Measurements

Mount the load cell according to its mechanical requirements, prevent side loads and binding, isolate vibration where needed, and allow the structure to settle before reading. For batching, inventory, or process control, define overload limits and periodically verify calibration.

The package includes the Weight-I2C Unit, a 20cm Grove cable, and a VH3.96-4P connector. Technical setup details are available in the M5Stack Weight-I2C documentation.