Overview
This 50kg half-bridge load cell is the small strain-gauge sensor used in bathroom and body scales. Each cell contains half of a Wheatstone bridge, so they are designed to be used in fours: the four cells at the corners of a platform combine into one full bridge that measures up to about 200kg total. With an HX711 amplifier, an Arduino or ESP32 reads the result.
You can also use a single 50kg cell with three fixed resistors to complete the bridge for lighter single-point projects, but the four-cell platform is the classic build.
At a Glance
Specifications
| Parameter | Value |
| Rated Capacity | 50 kg per cell |
| Bridge Type | Half bridge (2 gauges) |
| Typical Use | 4 cells = 1 full bridge, ~200 kg |
| Excitation Voltage | 3 - 5V (from HX711) |
| Wires | Red, Black, White (3) |
| Required Amplifier | HX711 24-bit ADC |
| Material | Coated alloy with mounting holes |
Wiring Guide
Combining 4 Cells
Wire the four half-bridge cells so they form one full bridge, then take three connections to the HX711 (E+, E-, and the signal pair). Many makers use a small combinator PCB, but it can be done by hand following the color scheme below.
| Bridge Point | HX711 |
|---|---|
| Excitation + | E+ |
| Excitation - | E- |
| Signal + | A+ (S+) |
| Signal - | A- (S-) |
HX711 to Arduino / ESP32
| HX711 Pin | Board |
|---|---|
| VCC | 5V (3.3V on ESP32) |
| GND | GND |
| DT | D2 |
| SCK | D3 |
Code Examples
Arduino (HX711 library)
#include "HX711.h"
HX711 scale;
const int DT = 2, SCK = 3;
void setup() {
Serial.begin(9600);
scale.begin(DT, SCK);
scale.set_scale(22000.0); // calibrate for your platform
scale.tare();
}
void loop() {
Serial.println(scale.get_units(10), 2); // kg
delay(500);
}