Generic DIY Pressure Sensor Kit 20kg with HX711AD, 4P DuPont Wire Shell

The load cell itself requires an excitation voltage between 5 and 10V DC to function correctly. The HX711 analog-to-digital converter module, however, operates on a separate logic supply voltage ranging from 2.6V to 5.5V DC. It is common to power the HX711 from the microcontroller's 3.3V or 5V rail while using a regulated 5V source for the load cell excitation.

Connection is straightforward using the included 4-pin DuPont shell. The pins typically correspond to VCC (to 5V), GND, DT (Data), and SCK (Clock) from the HX711 module. Connect VCC and GND to your board's power and ground. Connect the DT and SCK pins to any two digital I/O pins on your microcontroller. Extensive libraries and example code for the HX711 are available for the Arduino IDE.

Yes, the system requires a one-time calibration to map the digital output readings to an actual weight or force value. This is typically done in software using a known calibration weight. The process involves taking a reading with no load (tare) and then with a known weight placed on the load cell. The calibration factor is then calculated and stored in your microcontroller's code for subsequent measurements.

The system's precision is derived from the combination of the load cell's 1.0mV/V sensitivity and the HX711's 24-bit resolution. The load cell provides a stable, proportional analog signal, while the 24-bit ADC allows for detecting very small changes in that signal. Effective resolution can be in the milligram range, though overall accuracy depends on proper calibration, stable power supply, and mechanical mounting.