Over the years, many RobotShop customers have asked us about the easiest way to interface a load cell with an Arduino board so they can get accurate weight measurements. Instruments like load cells provide small signal values and need to be amplified for processing, so without additional electronics, these sensors cannot and should not be connected directly to an Arduino's I/O pins. Arduino boards like the UNO have a 10 bit ADC, which means that the resolution of the analog input pins are 5V/1024 ≈ 4.9mV. For this reason, variations less than 4.9mV will not be recognized by the Arduino board without the appropriate amplification and filtering. The two common approaches for interfacing a load cell with an Arduino are :
This is a companion discussion topic for the original entry at https://community.robotshop.com/index.php/blog/show/interfacing-a-load-cell-with-an-arduino-board