A measurement method for capacitive sensors based on a versatile direct sensor-to-microcontroller interface circuit - Publication - MOST Wiedzy

Search

A measurement method for capacitive sensors based on a versatile direct sensor-to-microcontroller interface circuit

Abstract

In the paper, there is presented a new time-domain measurement method for determining the capacitance values of capacitive sensors, dedicated, among others, to capacitive relative humidity sensors. The method is based on a versatile direct sensor-to-microcontroller interface for microcontrollers with internal analog comparators (ACs) and with precision voltage reference sources, e.g. digital-to-analog converters (DACs). The reference source can be replaced by a resistive divider attached to the negative input of the AC. The interface circuit consists only of a reference resistor Rr, a given capacitive sensor working as a voltage divider, and a microcontroller (its peripherals: AC, timer, DAC, I/O pins). A prototype of the proposed complete solution of a compact capacitive smart sensor based on an 8-bit ATXmega32A4 microcontroller has been developed and tested. The maximum possible relative inaccuracy of an indirectly measurable capacitance was analysed, and experimental research was also performed. The results confirmed that the relative errors of value determination for a capacitive sensor are less than ±0.06%, which corresponds to a capacitance measurement accuracy of less than 0.1 pF for a range of measured capacity values from 100 pF to 225 pF, which in turn corresponds to at least a 0.5% relative humidity resolution for commercial capacitive RH sensors (e.g. TE Connectivity HS1101LF and Philips H1).

Citations

  • 1

    CrossRef

  • 1

    Web of Science

  • 1

    Scopus

Details

Category:
Articles
Type:
artykuły w czasopismach
Published in:
MEASUREMENT no. 155, pages 1 - 11,
ISSN: 0263-2241
Language:
English
Publication year:
2020
Bibliographic description:
Czaja Z.: A measurement method for capacitive sensors based on a versatile direct sensor-to-microcontroller interface circuit// MEASUREMENT -Vol. 155, (2020), s.1-11
DOI:
Digital Object Identifier (open in new tab) 10.1016/j.measurement.2020.107547
Bibliography: test
  1. T. A. Blank, L. P. Eksperiandova, K. N. Belikov, Recent trends of ceramic humidity sensors development: A review, Sensors and Actuators B 228 (2016) 416-442. open in new tab
  2. Z. M. Rittersm, Recent achievements in miniaturised humidity sensors -a review of transduction techniques, Sensors and Actuators A 96 7 (2002) 196-210. open in new tab
  3. M. Dokmeci, K. Najafi, A High-Sensitivity Polyimide Capacitive Relative Humidity Sensor for Monitoring Anodically Bonded Hermetic Micropackages, Journal of Microelectromechanical Systems, 10 (2) (2001) 197-204. open in new tab
  4. Y. Kim, B. Jung, H. Lee, H. Kim, K. Lee, H. Park, Capacitive humidity sensor design based on anodic aluminum oxide, Sensors and Actuators B 141 (2009) 441-446. open in new tab
  5. A. Rivadeneyra, J. Fernandez-Salmeron, M. Agudo-Acemel, J. A. Lopez-Villanueva, L. F. open in new tab
  6. Capitan-Vallvey, A. J. Palmac, Printed electrodes structures as capacitive humidity sensors: A comparison, Sensors and Actuators A 244 (2016) 56-65.
  7. F. Reverter, O. Casas, Direct interface circuit for capacitive humidity sensors, Sensors and Actuators A 143 (2008) 315-322. open in new tab
  8. TE Connectivity Ltd., HS1101LF Relative Humidity Sensor, SENSOR SOLUTIONS /// HS1101LF HPC052_J (2015). open in new tab
  9. Philips Components, Humidity sensor 2322 691 90001 Product specification, (1996).
  10. G. Tuna, V. C . Gungor, Ch2 -Energy harvesting and battery technologies for powering wireless sensor networks, Industrial Wireless Sensor Networks. Woodhead Publishing (2016), 25-38. open in new tab
  11. M. Kuorilehto, M. Kohvakka, J. Suhonen, P. Hamalainen, M. Hannikainen T. D. Hamalainen, Ultra-low energy wireless sensor networks in practice, John Wiley & Sons, Ltd., Great Britain, 2007.
  12. F. Reverter, M. Gasulla, R. Pallàs-Areny, Analysis of power-supply interference effects on direct sensor-to-microcontroller interfaces, IEEE Transactions on Instrumentation and Measurement 56 (1) (2007) 171-177. open in new tab
  13. F. Reverter, The Art of Directly Interfacing Sensors to Microcontrollers, Journal of Low Power Electronics and Applications (2) (2012) 265-281. open in new tab
  14. F. Reverter, Ò. Casas, Interfacing differential resistive sensors to microcontrollers: A direct approach, IEEE Transactions on Instrumentation and Measurement 58 (10) (2009) 3405-3410. open in new tab
  15. F. Reverter, O. Casas, A microcontroller-based interface circuit for lossy capacitive sensors, Measurement Science Technology 21 (2010) 065203, 1-8. open in new tab
  16. F. Reverter, O. Casas, Interfacing Differential Capacitive Sensors to Microcontrollers: A Direct Approach, IEEE Transactions on Instrumentation and Measurement 59 (2010) 2763-2769. open in new tab
  17. J. E. Gaitán-Pitre, M. Gasulla, R. Pallàs-Areny, Analysis of a Direct Interface Circuit for Capacitive Sensors, IEEE Transactions on Instrumentation and Measurement 58 (9) (2009) 2932-2937. open in new tab
  18. J. Pelegrí-Sebastiá, E. García-Breijo, J. Ibáńez, T. Sogorb, N. Laguarda-Miro, J. Garrigues, Low-Cost Capacitive Humidity Sensor for Application Within Flexible RFID Labels Based on Microcontroller Systems, IEEE Transactions on Instrumentation and Measurement 61 (2) (2012) 545-553. open in new tab
  19. O. Lopez-Lapeńa, E. Serrano-Finetti and O. Casas, Calibration-less direct capacitor-to- microcontroller interface, Electronics Letters 52 (4) (2016) 289-291. open in new tab
  20. Z. Kokolanski, J. Jordana, M. Gasulla, V. Dimcev, F. Reverter, Direct inductive sensor-to- microcontroller interface circuit, Sensors and Actuators A 224 (2015) 185-191. open in new tab
  21. Z. Kokolanski, F. Reverter, C. Gavrovski, V. Dimcev, Improving the resolution in direct inductive sensor-to-microcontroller interface, Annual Journal Of Electronics (2015) 135-138. open in new tab
  22. Z. Czaja, A microcontroller system for measurement of three independent components in impedance sensors using a single square pulse, Sensors and Actuators A 173 (2012) 284-292. open in new tab
  23. Z. Czaja, An implementation of a compact smart resistive sensor based on a microcontroller with an internal ADC, Metrology and Measurement Systems 23 (2016) 255-238. open in new tab
  24. Z. Czaja, Time-domain measurement methods for R, L and C sensors based on a versatile direct sensor-to-microcontroller interface circuit, Sensors and Actuators A 274 (2018) 199- 210. open in new tab
  25. F. Reverter, X. Li, G. C M Meijer, Stability and accuracy of active shielding for grounded capacitive sensors, Measurement Science and Technology 17 (2006) 2884-2890. open in new tab
  26. F. Reverter, X. Li, G. C M Meijer, A novel interface circuit for grounded capacitive sensors with feedforward-based active shielding, Measurement Science and Technology 19 (2008) 025202 (5pp). open in new tab
  27. Atmel Corporation, 8/16-bit AVR XMEGA A4 Microcontroller. ATxmega128A4, ATxmega64A4, ATxmega32A4, ATxmega16A4, (2013), Available at: http://ww1.microchip.com/downloads/en/DeviceDoc/Atmel-8069-8-and-16-bit-AVR- open in new tab
  28. AMEGA-A4-Microcontrollers_Datasheet.pdf. open in new tab
  29. Microchip Technology Inc., AVR1300: Using the Atmel AVR XMEGA ADC, (2017), Available at: http://ww1.microchip.com/downloads/en/Appnotes/00002535A.pdf. open in new tab
  30. F. Reverter, R. Pallàs-Areny, Effective number of resolution bits in direct sensor-to- microcontroller interfaces, Measurement Science and Technology 15 (2004) 2157-2162. open in new tab
  31. F. Reverter, R. Pallàs-Areny, Uncertainty reduction techniques in microcontroller-based time measurements, Sensors and Actuators A 127 (2006) 74-79. open in new tab
  32. K. Kolikov, G. Krastevy, Y. Epitropov, A. Corlat, Analytically determining of the relative inaccuracy (error) of indirectly measurable variable and dimensionless scale characterizing quality of the experiment, Computer Science Journal of Moldova 20 (58) (2012) 15-32. open in new tab
  33. I. Farrance, R. Frenkel, Uncertainty of measurement: A review of the rules for calculating uncertainty components through functional relationships, The Clinical Biochemist Reviews 33 (2012), 49-75.
  34. Agilent Technologies, Agilent 34410A/11A 6 1/2 digit multimeter user's guide (2012). open in new tab
Verified by:
Gdańsk University of Technology

seen 27 times

Recommended for you

Meta Tags