Digital filtering in smart load cells

This paper describes an application of a Self Adaptive Pseudo-Moving Average Filter used in the implementation of a Smart Load Cell, to combine a stable digital output with a fast response to weight changes. The Smart Load Cell is a data acquisition solution using a single chip RISC microcontroller with very few other active and passive components around and taking advantage of the ratiometric functioning of load cell. The use of Smart Load Cells with digital outputs needs a cost effective in digital filtering of the final converter results for each Smart Load Cell. The technique is established by theoretical analysis and is justified by means of simulation and experimental results. The paper also describes an example of software calibration of a Multi-Load-Cells weighbridge, using four smart load cells.CEL-Cachapuz Electrónica Lda