Implementation scheme for capacitive touch sliding

The capacitive touch sensor measure the value changes of capacitance. The changes were sent to MCU after they were sensed by the analog hardware. Add periodic charging voltage to RC network. The terminal voltage of capacitance in the RC network will fall off in the settled charging time because of the change of permittivity in the network caused by finger touching activity. We can judge whether the finger touch the sensor by measure the change of the terminal voltage value of capacitance in the RC network. We can apply this theory to judge whether the finger touch the slider to change the volume of the sound box.