Autonomous and Low-Cost Data Acquisition System for Impedimetric Sensors in Precision Horticulture

Precision horticulture demands affordable, versatile platforms for testing various sensors. Current solutions are costly, complex, and limited, hindering widespread adoption. Here we present a practical and modular sensor system designed for the integration and evaluation of multiple sensor types. The platform includes an impedance analyzer, two multiplexers and a 16channel Raspberry Pi. We have fully characterized the electrical impedance spectroscopy properties of two impedimetric sensors - an ammonia sensor and a humidity sensor - over a frequency range from 500 Hz to 10 MHz. The chemiresistive ammonia sensor operated optimally at 4 kHz, demonstrating sensitivity through impedance magnitude measurements. The capacitive humidity sensor operated effectively at around 1 MHz, demonstrating sensitivity to humidity levels despite harsh environmental conditions. Our results show the platform's effectiveness in both lab and field settings, enhancing precision horticulture by enabling rapid sensor evaluation, accelerating agricultural technology advances, and promoting efficient practices.