12. 触摸传感器

触摸传感器系统建立在一个基底上，此基底在保护平面下带有电极和相关连接。当用户触碰表面时，即触发电容变化，并产生一个表示触摸是否有效的二进制信号

A touch-sensor system is built on a substrate which carries electrodes and relevant connections under a protective flat surface. When a user touches the surface, the capacitance variation is triggered and a binary signal is generated to indicate whether the touch is valid.

ESP32可提供多达10个触摸GPIO。 这10个触摸GPIO为 0, 2, 4, 12, 13, 14, 15, 27, 32, 33

>>> import machine, Pin
>>> tc = machine.TouchPad(Pin(35))

当引脚为悬空时:

>>> tc.read()
1129

当用户触碰表面时:

>>> tc.read()
89

todo:

TouchPad.config()