SparkFun
SparkFun OpenScale
The SparkFun OpenScale is an open-source weight measurement board designed for load cells. Simply connect a four-wire or five-wire load cell of any capacity,...
Get notified when back in stock
The SparkFun OpenScale is an open-source weight measurement board designed for load cells. Simply connect a four-wire or five-wire load cell of any capacity, plug into USB, open a serial terminal at 9,600 bps, and you'll immediately see mass readings. A built-in serial menu lets you configure calibration values, sample rate, timestamps, and units of precision.
Designed for static and continuous weighing applications — such as monitoring systems, conveyor belts, and long-term data logging — the OpenScale can operate unattended for months. An on-board TMP102 temperature sensor records ambient temperature alongside weight data.
Key Features
- HX711 24-Bit ADC – High-resolution load cell amplifier for accurate weight measurement
- ATmega328P Microcontroller – Handles serial communication and configuration
- TMP102 Temperature Sensor – Records ambient temperature alongside weight data
- FT231 USB-to-Serial – Mini-USB connection for data output
- Configurable Baud Rate – 1,200 to 1,000,000 bps (default 9,600 bps 8-N-1)
- Serial Configuration Menu – Set calibration, sample rate, timestamps, and precision via terminal
- Multi-Cell Support – Works with single load cells or four sensors in Wheatstone bridge configuration
Ideal For
- DIY weigh scales and measurement systems
- Long-term unattended weight monitoring
- Industrial and conveyor belt weighing
- Data logging with OpenLog or similar serial loggers
Package Contents
- 1× SparkFun OpenScale Board
Resources
Jargon buster
Plain-language definitions for the technical terms used above.
- ADC
- An analogue-to-digital converter reads a changing voltage and turns it into a number the microcontroller can use. It matters when connecting analogue sensors such as light, sound, or variable-resistor sensors.
- ATmega328P
- An 8-bit microcontroller chip used on many Arduino Uno-compatible boards. Knowing the controller uses an ATmega328P helps you understand its memory, speed, pin compatibility, and the Arduino sketches it can run.
- baud
- Baud is the signalling rate of a serial connection, often used as the speed setting for UART communication. Matching the baud rate matters because both connected devices must use the same setting for readable data.
- microcontroller
- A microcontroller is a small computer on a single chip that runs a stored program and controls connected inputs and outputs such as buttons, sensors, displays and communication interfaces. In a device built around one, it is the part that executes the code and coordinates the device's behaviour.
Find this product in
Brands
Sensors & Input
SparkFun OpenScale Schematic
Schematic · 77.9 KB · Click any page to view full size
HX711 Load Cell Amplifier Datasheet
Datasheet · 263.2 KB · Click any page to view full size
TMP102 Temperature Sensor Datasheet
Datasheet · 1.1 MB · Click any page to view full size
Supplier page — sparkfun.com
Supplier Description · 1.1 MB · Click any page to view full size
Resources & Downloads
Guides, code examples, and more
SparkFun OpenScale Eagle Files
Schematic · ZIP · 176.8 KB
Eagle design files for the SparkFun OpenScale PCB.
SparkFun OpenScale Arduino Library
Example Code · ZIP · 14.2 KB
Arduino library and example code for interfacing with OpenScale.
SparkFun OpenScale Particle Sketch
Example Code · ZIP · 3.7 KB
Example Particle sketch for using the SparkFun OpenScale.
Source Code
Open-source libraries, firmware & example projects for this product
An open source board for load cell reading and configuration based on the HX711 and ATmega328.
7c0e019
about 7 years ago
· 88 commits
- Documentation Merge branch 'v04' over 9 years ago
- firmware Changed HX711 start up to match lib changes over 7 years ago
- hardware Update SparkFun_openScale.sch about 7 years ago
- Production removed tmp102 silk from panel v10 almost 10 years ago
- .gitattributes :space_invader: Added .gitattributes & .gitignore files over 11 years ago
- .gitignore Initial commit over 11 years ago
- Hive-Electronics.jpg Adding photos and link to project article. over 10 years ago
- OpenScale Board Dimensions.png Fix screw terminal spacing. Small firmware changes. over 10 years ago
- readme.md Update readme. Remove old varience ino. over 7 years ago
Related Tutorials
Free guides on learn.littlebird.com.au
