Towards a reliable approach on scaling in data acquisition

TL;DR

This paper introduces a new scalable method for converting ADC digital values into physical units, validated through a case study and implementation on a wireless sensor node.

Contribution

It presents a general scaling method and a SageMath script for easy computation, enhancing accuracy and flexibility in digital measurement systems.

Findings

Validated the scaling method through calculus-based case study.

Implemented the approach on a low-cost wireless sensor node.

Demonstrated improved measurement accuracy and system reliability.

Abstract

Data acquisition is an important process in the functioning of any control system. Usually, the acquired signal is analogic, representing a continuous physical measure, and it should be processed in a digital system based on an analog to digital converter (ADC) and a microcontroller. The ADC provides the converted value in ADC units, but the system and its operator need the value expressed in physical units. In this paper we propose a novel design solution for the scaling module, which is a key component of a digital measurement system. The scaling module refers to fitting the sensor result of a variable number of bits depending on the ADC resolution into physical units. A general method for scaling is proposed and a SageMath script is presented for obtaining easily the scaling function. In the last part of the paper, the proposed method is validated in a case study, by calculus, and it is implemented on a low-cost development system in order to create a wireless sensor node.