Touch Film Applications
Self-capacitance determines whether a finger touches the electrode by detecting changes in electrostatic capacitance. The capacitance is scanned and detected according to a certain cycle. It can be judged whether a finger touches the electrode based on the change in the measured value. The MCU cycles according to a certain cycle. The capacitance of the electrode is scanned and detected. When the finger is away from the electrode, the capacitance value remains at a stable count value. When a finger approaches or touches the capacitance value, the capacitance value increases and the count value increases. When the finger moves away from the electrode, the capacitance value decreases by the count value. The count value that drops and remains at a stable value when the finger is away from the electrode is called the base value. We superimpose a threshold value on this base value as the critical value. When the count value is higher than this critical value, the judgment switch is ON. When the count value Below this critical value, the switch is judged to be OFF.
