I have a 50 kg load cell and an HX711 sensor (as in the image below), my problem is that in all the tutorials I've seen people use load cells with 4 output wires or 2 cells with 3 output cables, I just need to connect only one, so I can weigh objects. I do not know if I really need 2 load cells for what I want, but I mainly want to weigh food. I have been testing with this tutorial as a base since it works for many people https://tutorials-raspberrypi.com/digital-raspberry-pi-scale-weight-sensor-hx711/ I'm learning, thank you.

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    \$\begingroup\$ You can probably create the missing leg of the bridge with two good quality low temperature coefficient resistors to supply the balancing point for the amplifier. Link has the same sort of details - forum.arduino.cc/index.php?topic=386749.0 \$\endgroup\$
    – KalleMP
    Sep 17, 2017 at 15:53

1 Answer 1


To use a single load cell, you make the '4th wire' like this


simulate this circuit – Schematic created using CircuitLab

Check with your datasheet for the values of R1 and R2. They need to be low enough to power A- properly, but high enough to not load the E terminals too much. 1k will be a good default if they're not specified.

Mount R1 and R2 such that they share the same temperature. You won't need much tempco, and much temperature difference, to get a significant reading.

To use a second load cell, place it in the circuit where the 'ref wire' block is, but invert the red and black wires. This will make its output in antiphase to the first, so the differential input will add them with the same gain.


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