HX711 with 4 load cells

[DaveX]

@sonofcy

I have NO idea what you are doing with the four load cells. I strongly doubt it will work;

That could be the right wiring for using 4x half-bridge/three-wire load cells together into a single 4-wire Wheatstone bridge, if the wire colors are correct and the Red is the center-tap of the half bridges, as per:

4x Load Cells Hx711, smart weight scale

[image] They look like three-wire half-bridge load cells with two strain-gauges per cell. If you carefully wire them up in a ring, you can have two strain gauges that constructively sum the strains in each leg of a wheatstone bridge between the half-bridge cell's center tap wire: [image] per https://electronics.stackexchange.com/questions/102164/3-wire-load-cells-and-wheatstone-bridges-from-a-bathroom-scale/199470#199470 The resistances look OK as far as the 3-digit resolution goes, but …

Bathroom scales often use this 4x half-bridge cell wiring, with a cheap 50kg cell at each corner/foot of the scale.

@Wawa

Those Chinese HX711 boards are simply not designed for 3.3volt processors.

The Sparkfun HX711 boards are designed to accommodate the 3.3v processors:

SparkFun Load Cell Amplifier - HX711

...with the 5V on the VCC line and the processor data voltage on the VDD line as per Load Cell Amplifier HX711 Breakout Hookup Guide - SparkFun Learn