Load cells use a four-wire Wheatstone bridge configuration to connect to the HX711. These are commonly colored RED, BLK, WHT, GRN and YLW. Each color corresponds to the conventional color coding of load cells:
- Red (Excitation+ or VCC)
- Black (Excitation- or GND)
- White (Amplifier+, Signal+ or Output+)
- Green (A-, S- or O-)
- Yellow (Shield)
The YLW pin acts as an optional input that is not hooked up to the strain gauge but is utilized to ground and shield against outside EMI (electromagnetic interference). Please keep in mind that some load cells might have slight variations in color coding.