Project 11: Verfication testing, consumer 10 lbs load cell with Hx711 ADC.
2018-11-18
Objective:
To demonstrate basic functionality of the Hx711 analog-to-digital converter.
In 2017 I purchased an American Weigh Scales (AWS) digital kitchen scale. This unit quickly failed, the digital display just stuck on an incorrect value. I returned to vendor and was sent another unit. This unit failed in the same manner. A product review is posted American Weigh Scales Review. This second unit was dismantled to use the scale load cell and fixture.
The project is based on:
Tutorial to Interface HX711 Balance Module With Load Cell.
Link to Hx711 Load Cell Amplifier Interface with Arduino.
Link to Load Cell Amplifier HX711 Breakout Hookup
Guide.
Materials:
1. Arduino Uno connected by USB cable to linux computer.
2. Load Cell with fixturing.
3. Hx711 24-bit analog-to-digital converter. DIYmall 2pcs Hx711 Load Cell Conversion Module Sensors for Arduino Microcontroller for $6.99 USD.
4. Generic jumper wires. Kuman 120pcs Breadboard Jumper Wires Multicolor Pack for $7.48 USD.
Software:
1. Linux OS2. Arduino IDE 2.1 - GUI provided by Arduino to upload instructions to microcontroller
3. Hx711 library and calibration code from github.
Hardware Set-Up, Compiling, and Testing:
1. Simply plug in circuit as per diagram.2. Run Arduino IDE.
3. Load Hx711 libraries to Arduino IDE.
4. Run Hx711 calibration code.
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Conclusion
Enjoy. Perhaps the price of the AWS kitchen scale is worth it just for the load cell?
Design credit knxops.com in cooperation with Ltimas and co.
Copyright © 2019 by Gregory Altimas aka Greg Altimas