Impact of cable length on the performance of low-cost sensors in single-board computer monitoring systems

¹ Department of Energy and Process Engineering, Norwegian University of Science and Technology - NTNU, Trondheim, Norway
² Department of Architecture & Technology, Norwegian University of Science and Technology - NTNU, Trondheim, Norway

Abstract

The increasing adoption of low-cost monitoring devices in environmental systems is a testament to their cost-effectiveness, versatility, and reliability. These devices, when paired with host minicomputers such as Raspberry Pi or Arduino, form the backbone of modern, budget-friendly monitoring solutions. This study addresses a crucial question in the deployment of such systems: the effect of cable length on the integrity of sensor data. It meticulously evaluates three widely-used sensors—the MCP9808 for temperature, the BME280 for temperature, and humidity, and the SCD30 for temperature, humidity, and CO2 concentration—across varying cable lengths from 10 cm to 6 m, utilizing the I2C communication protocol for connectivity to the Raspberry Pi. Results indicate that extended cable lengths do not significantly affect the accuracy of sensor readings, with CO2 and RH measurements showing high correlation values (r² > 0.98) and temperature readings displaying lower, yet reliable, r² values (0.82 to 0.92). Time-series and error analysis further confirm the sensors’ performance. This study provides critical insights into the design of cost-effective monitoring systems and suggests that data accuracy is maintained across varying cable length, offering flexibility for environmental monitoring in diverse and spatially challenging settings.