Arduino Projects: HX711 Module

Out of all the interesting Arduino Projects we have worked on in the past, this turned out to be a little more exciting. Here comes the not so popular tensiometry beam with the HX711 module that allows you to find the weight of an object.

Strain gauges are widely used in industry to measure tensions and strains in sophisticated constructions. Today we are not going to build a bridge but we will make a simple weight and compare its readings with a kitchen weight. Let’s start with the parts needed for this project:

The first thing that we have to do is to solder cables from the tensiometry beam to the HX711 module. There are 4 cables to solder but the module has 6 pins, pins B- and B+ are not connected to anything. Take a look at the image below to see what I mean.

  • E+ – RED
  • E- – BLACK
  • A+ – WHITE
  • A- – GREEN

When those cables are soldered, we can connect the module to Arduino. There are only 4 cables to connect VCC, GND, DT, and SCK. You can use different pins for DT and SCK but you have to change the code accordingly. Here is the pictorial.

The best way to connect this module is to use breadboard cables with female to male connectors.

And here is the circuit with everything connected.

Before the test, we have to fix the beam to something. I decided to screw it to a piece of wood with 2 screws. Make sure you screw on the side where cables are and that the arrow on the front of the beam is pointing upward.

Before uploading the code we have to install the library in the Arduino IDE. Here is a link where you can download it: All the code does is displaying weight in kg on the serial port. Keep in mind that it is calibrated for a 5kg beam if you have a different one you should calibrate it before use.

There is a code in the examples with a quite good explanation on how to calibrate it.

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