SparkFun OpenScale - IoT

The SparkFun OpenScale IoT simplifies the process of creating a high-accuracy scale without the need for complex coding. Built around the robust ESP32-PICO-MINI, this wireless solution supports various load cell types and offers versatile interface options. Ideal for applications such as monitoring beehive weight over time or accurately measuring coffee beans, it transforms any standard load cell into a fully functional, connected weighing system.

With its user-friendly setup, connecting the OpenScale is a breeze. Simply attach a four or five-wire load cell, and configure your calibration, sample rates, and precision through an intuitive terminal menu. This allows you to create a DIY weigh scale for any application, whether using a single load cell or arranging four sensors in a Wheatstone bridge configuration.

The device offers flexible connectivity options, including Bluetooth/BLE and a wired USB-C/serial connection for accessing the terminal menu at 115,200bps. Additionally, it can connect to a local 2.4GHz WiFi network for live data viewing and Over-The-Air (OTA) firmware updates. The integrated Qwiic connector makes it easy to add I2C sensors and displays without soldering.

For precise and long-term use, the OpenScale integrates multiple sensing technologies. The onboard HX711 functions as a 24-bit ADC when using four strain gauges to read a Wheatstone bridge with high precision. This design is ideal for static load applications or scenarios requiring continuous readings, such as conveyor belt systems. The device can operate for months without user intervention, and an integrated TMP102 sensor logs ambient temperature to account for environmental changes. A 3-pin screw terminal is also available for attaching an external temperature probe directly at the measurement site.