SparkFun Qwiic Scale - NAU7802

Translating physical forces into digital data usually requires managing multiple components, but the SparkFun Qwiic Scale simplifies the entire process. With the on-board NAU7802, this Qwiic breakout board acts as an all-in-one amplifier and Analogue-to-Digital Converter (ADC). It effortlessly translates the minuscule resistance changes from a standard load cell into an easily readable digital signal, allowing you to accurately measure the weight of an object directly from your microcontroller.

Versatile Application

By converting analogue pressure into a true I²C output, this board serves as a versatile function for a wide variety of custom projects:

• Process Control: Automate precise ingredient measurements for manufacturing or complex DIY setups.
• Smart Inventory: Create a pressure-sensitive shelf that tracks bin weight to know exactly when supplies are running low.
• Presence Detection: Build hidden, weight-based triggers for interactive installations or smart-home automation.

Completely Solderless Setup

To make building your custom scale as fast as possible, the board features an incredibly useful four-pin spring terminal. Simply press down and insert your load cell wires with absolutely no soldering required. Additionally, communication to your microcontroller is handled entirely through our plug-and-play Qwiic Connect System, though standard 0.1-inch spaced pins (including an interrupt pin and AVDD) are fully broken out to the edge for breadboard users.

Using Multiple Scales

Please be aware that the NAU7802 has a fixed, hardware-defined I²C address of 0x2A. If your project requires multiple scales on the same bus, you will need to use a multiplexer (like the Qwiic Mux Breakout) to communicate with each without conflicts.

• Schematic
• EagleFiles
• Hookup Guide
• Datasheet (NAU7802)
• Getting Started with Load Cells
• Libraries:
  • Arduino
  • Python / MicroPython / CircuitPython
• Hardware Repo