An Ultra-Low-Cost RCL-Meter

Sensors

卷:22

Peter Stallinga¹  Rui Guerra¹  Pedro M. C. Inácio¹ 

[1] CEOT—Center for Electronics, Optoelectronics and Telecommunications, University of Algarve, Campus Gambelas, 8005-139 Faro, Portugal;

关键词: impedance meter;    RCL-bridges;    portable instrument;    AVR^® micro-controller;    low-cost;    internet of things;   

DOI  :  10.3390/s22062227

来源: DOAJ

【 摘 要 】

An ultra-low-cost RCL meter, aimed at IoT applications, was developed, and was used to measure electrical components based on standard techniques without the need of additional electronics beyond the AVR^® micro-controller hardware itself and high-level routines. The models and pseudo-routines required to measure admittance parameters are described, and a benchmark between the ATmega328P and ATmega32U4 AVR^® micro-controllers was performed to validate the resistance and capacitance measurements. Both ATmega328P and ATmega32U4 micro-controllers could measure isolated resistances from 0.5 Ω to 80 MΩ and capacitances from 100 fF to 4.7 mF. Inductance measurements are estimated at between 0.2 mH to 1.5 H. The accuracy and range of the measurements of series and parallel RC networks are demonstrated. The relative accuracy (a_r) and relative precision (p_r) of the measurements were quantified. For the resistance measurements, typically a_r, p_r < 10% in the interval 100 Ω–100 MΩ. For the capacitance, measured in one of the modes (fast mode), a_r < 20% and p_r < 5% in the range 100 fF–10 nF, while for the other mode (transient mode), typically a_r < 20% in the range 10 nF–10 mF and p_r < 5% for 100 pF–10 mF. a_r falls below 5% in some sub-ranges. The combination of the two capacitance modes allows for measurements in the range 100 fF–10 mF (11 orders of magnitude) with a_r < 20%. Possible applications include the sensing of impedimetric sensor arrays targeted for wearable and in-body bioelectronics, smart agriculture, and smart cities, while complying with small form factor and low cost.

【 授权许可】

Unknown