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What Is The Data Processing Process Of The Industrial Capacitive Touchscreen?

With the development of science and technology, many of our product applications now use industrial capacitive touchscreen. Therefore, capacitive touch screens have become more and more popular. So do you know what the data processing process of a capacitive touch screen is like? Let us have a chat today.

Data Processing Process Of Industrial Capacitive touchscreen

The data processing process of the capacitive touch screen is like this. After it receives the touch signal. The touch data is converted into electrical pulses and sent to the touch screen control IC for processing. The signal is first amplified by a low-noise amplifier LNA, then through analog-to-digital conversion and demodulation, and finally sent to a DSP for data processing.

A capacitive touch screen generally has M+N (M columns and N rows) physical capacitive touch sensors. The M+N interlaced sensors form M*N capacitive sensing points. When the user's finger approaches the touch screen, its capacitance will change accordingly. The distance between the sensors (that is, the distance between adjacent rows or columns) is usually about a few millimeters, and this distance determines the physical resolution M*N of the touch screen.

The Difference In Data Processing Between Industrial Capacitive touchscreen And LCD Module

The coordinate system between the capacitive touch screen module and the LCD module is completely different. The pixel coordinates of an LCD module are generally determined by its resolution. For example, a WVGA screen, its resolution is 800*480. In other words, there are 800 rows, each with 480 RGB pixels. Thus, a specific position can be determined by the pixel points (x, y) in the X and Y directions. The capacitive touch screen module determines the coordinate system according to its original physical size in the X and Y directions.

A reasonable mapping method must exist between the two coordinate systems to ensure the correctness of input and output operations. Therefore, the DSP processor of the touch screen control IC has to perform pixel mapping conversion between the capacitive touch screen module and the LCD module on the obtained data. This ensures that the touch point of the user on the touch screen is the point pointed by the user.