Novel capacitive pressure and touch detection method and circuit

Abstract

The invention discloses a novel capacitive pressure and touch detection method and circuit, which comprises a main control MCU and two metal sheets forming two electrodes of a capacitor, a medium is loaded between the two metal sheets, the main control MCU comprises a GPIO input end and a GPIO output end, the GPIO input end is connected with a first electrode of the capacitor, the GPIO output endis connected with a second electrode of the capacitor, wherein a VIH threshold level or a VIL threshold level of a level comparator is input as a Vc (t) value at a selected t moment; a timing countercounting function and an external input triggering interrupt function of the main control MCU are started; when external input interruption is triggered, a counting value in the timing counter is read, and the counting value reflects the current detected capacitance value; and the main control MCU detects that the capacitance value is changed, so that whether the pressure is increased or decreasedor not and whether touch exists or not can be judged. Not only are the purposes of detecting the pressure change and effectively and stably pressing down and lifting up the touch key achieved, but also the cost of the scheme is low, and a pressure sensor factory is easy to produce.

Description

technical field [0001] The invention relates to the technical field of display touch detection, in particular to a new capacitive pressure and touch detection method and circuit. Background technique [0002] With the continuous development of display touch technology and the continuous improvement of people's quality of life requirements, pressure and touch technology has become more and more widely used in applications. For example, touch screens on smart phones, touch buttons on water heaters, microwave ovens, and rice cookers, etc., can almost be said to be without "touch". [0003] Pressure and touch solutions are in high demand in realization and production. At present, the design of pressure and touch solutions that are common in the market is relatively complicated, and most of them are realized by producing pressure sensors and using the ADC of a dedicated IC chip to detect changes in the voltage (or current) value of the sensor terminal. In addition, most pressur...

AI Technical Summary

Problems solved by technology

In addition, this type of pressure sensor has high requirements in the manufacturing process, the cost of the solution is high, the production equipment is complex and precise, the pressure sensor after production is expensive, and a dedicated main control MCU with ADC conversion function is required for detection

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