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Discussion - EVE / Re: Capacitive touch screen calibration
« on: June 17, 2020, 03:48:27 PM »
Hello,
Theres a slightly better definition of the operation of the touch registers available in the BT81x programmers guide:
This indicates that the values stored in REG_TOUCH_SCREEN_XY represent a twos compliment number (0x8000 = -32768). A return value of 0x65xx for either the x or y value of the register would represent a positive number.
Is this value obtained pre or post screen calibration?
Best Regards,
BRT Community
Theres a slightly better definition of the operation of the touch registers available in the BT81x programmers guide:
Code: [Select]
The raw touch screen (x, y) values are available in register REG_TOUCH_RAW_XY. The range of
these values is 0-1023. If the touch screen is not being pressed, both registers read 0xFFFF.
These touch values are transformed into screen coordinates using the matrix in registers
REG_TOUCH_TRANSFORM_A-F. The post-transform coordinates are available in register
REG_TOUCH_SCREEN_XY. If the touch screen is not being pressed, both registers read 0x8000
(-32768). The values for REG_TOUCH_TRANSFORM A-F may be computed using an on-screen
calibration process.
This indicates that the values stored in REG_TOUCH_SCREEN_XY represent a twos compliment number (0x8000 = -32768). A return value of 0x65xx for either the x or y value of the register would represent a positive number.
Is this value obtained pre or post screen calibration?
Best Regards,
BRT Community