Display Touch Element
The Display Touch Element interface with the chips that can detect touch positions on a touch enabled display.
The touch events are used together with the displayed buttons. Based on the coordinates an active DisplayButton Element is searched and the actions of the Button Element are triggered. This allows having multiple buttons placed on the same display for different purpose.
There are some different chips and technologies available for touch detection.
Capacitive Touch Sensors
Capacitive touchscreens are often used on smartphones and tablets as they are very responsive to a touch and even work through screen protector glass. They work by messuring the changing capacity when a object (finger or stylus) is nearby the surface. They don’t need any touch force. However they may report accidentally touch events.
The DisplayTouchGT911 Element is enabling the GT911 is a 5-Point Capacitive Touch Sensors for 7" to 8" panels using the I2c bus for communication. It can deliver Input results every 40 / 10 msec.
Resistive Touch Sensors
Resistive touchscreens work by messuring the changed resistance when some pressure is made on the surface. They are often cheaper and may be better in rough environments and do not support multi-touch events. A stylus is often required to create accurate touch events.
See also
- DisplayButton Element
- https://www.makeuseof.com/tag/differences-capacitive-resistive-touchscreens-si/