This article shows the wiring of cheaper “half bridge load cells” (YZC-161E). Such half bridge weight sensors are available on Ebay partly even together with a HX711 for only 9€. On Amazon they cost about 13€ 🛒
At constant temperatures, these sensors work okay, but these cheap sensors show a so-called temperature drift. This means that the measurement result changes with increasing temperature. Therefore the better weight sensors are to be recommended.
In addition, the measured weight changes over time. If you only want to measure the relative honey yield in a short period of time, this can be sufficient. However, the absolute weight drifts off over a longer period of time.
Compensation of temperature-dependent deviations
The HoneyPi firmware has a so-called temperature compensation built in, so that the above mentioned deviations can be compensated by a calibration.
Here are some graphics that actually all show the same thing: The wiring of the four half bridges weight sensors. The red cables at the load cells lead to the HX711 (A/D converter).
- 4x Half Bridge load cells on HX711
- Green A-
- Grey A+
- Black E-
- Red E+
Translated 19.10.2019 by JK