Development and Experimental Comparison of Low-Cost, Reliable Capacitive Touch Sensing Boards

作者：Akkoc Ferat^*; Sahin Ozge Cihanbegebdi

来源：Sensors (Switzerland), 2016, 16(11): 1786.

DOI：10.3390/s16111786

• capacitive touch sensors
• mutual and self-capacitance
• charge transfer
• noise detection
• frequency hopping

In this study, two types of direct interface capacitive sensors, self- and mutual-capacitance, were developed and compared experimentally. Electromagnetic Compatibility (EMC) tests- International Electrotechnical Commission (IEC) 61000-4-3, IEC 61000-4-4, IEC 61000-4-6-were applied in an accredited laboratory to measure the immunity of the sensors against radiated and conducted interference. The frequency hopping algorithm could be implemented for the mutual-capacitance sensor without using any particular circuit. The effects of EMC disturbance were detected by means of a new noise detection algorithm and when the signal-to-noise ratio (SNR) became lower, the operation frequency of the sensors switched to an undisturbed frequency to ensure safe operation. For this purpose, a new noise detection algorithm was developed and frequency hopping was performed with a standard controller. Both cards were tested under several conditions and their performances compared.

• 出版日期2016-11