SparkFun Hx711

The SparkFun load cell amplifier is a small breakout board for the HX711 IC, allowing you to easily read load cells for weight measurement. When you connect the amplifier to your microcontroller, you can read the changes in resistance of the load cell and achieve very accurate weight measurements with some calibration. This can be useful for creating your own industrial scale, process control, or simple presence detection.

The HX711 uses a two-wire interface (Clock and Data) for communication. The GPIO pins of any microcontroller should work, and numerous libraries have been written to facilitate reading data from the HX711. Load cells use a four-wire Wheatstone bridge to connect to the HX711. These are typically available in red, black, white, green, and yellow. 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 (Shielding). The yellow pin serves as an optional input that is not connected to the strain gauge but is used for grounding and shielding against external electromagnetic interference. Please note that some load cells may have slight variations in color coding.