EarthLCD ezLCD-405, Manual, Page: 33 / 173

e z L C D -­‐ 4 0 5 | 33
Rev.
© 2016 Earth Computers Tech. Inc.
1.5.3 Data Protocols
Currently, the ezLCD-­‐405 can broadcast the touch screen data using the following protocols:
1. ezButton
·∙ Touch screen buttons can be defined BUTTON_DEF command.
·∙ ezLCD sends Button Down and Button Up events for the buttons defined by the
BUTTON_DEF command.
·∙ Easy protocol. Button IDs and events are coded in 1 byte.
·∙ Events are sent only once per button state change.
2. cuButton
·∙ Similar to the ezButton, however the button states are sent continuously, 5 to 20 times
per second.
3. CalibratedXY
·∙ ezLCD sends TOUCH_X and TOUCH_Y packets (X and Y coordinates), when the screen is
pressed
·∙ ezLCD sends PEN_UP packets when the touch screen is not pressed.
·∙ Multi-­‐byte packed oriented protocol.
·∙ Packets are sent continuously, 5 to 50 times per second.
Note: Upon the Power-­‐Up the ezLCD does not send any touch screen data until the proper
protocol is selected by the TOUCH_PROTOCOL command.
Differences between the ezButton and cuButton protocols.
1. ezButton ezLCD sends the event only once per button state change
cuButton The button states are reported continuously, 5 to 20 times per second.
2. ezButton ezLCD sends Button Down and Button Up events .
cuButton ezLCD sends Button Down and Button None states .