Detailed Explanation of MCU Capacitive Touch Sensing Technology Principles 2

The control circuit is responsible for converting the sensed changes in capacitance values into digital signals and processing them to achieve detection and positioning of touch operations. The control circuit usually consists of a microcontroller unit (MCU) and some peripheral circuits. MCU is the core part that controls the entire touch screen. It can read the voltage value of the capacitive sensor and determine whether a touch operation has occurred and the location of the touch through a series of algorithms and processing. diode

Specifically, the control circuit first samples the capacitive sensor by periodically measuring the voltage between the capacitive electrode and the reference electrode. Then, the MCU will calculate the corresponding capacitance value based on the sampled voltage value and compare it with the previous capacitance value. If the capacitance value exceeds a certain threshold, it will be judged as a touch operation. diode