Oct. 04, 2018
Page
10
of 18
Rev 1.00
M480 emWin
The following figure shows the application halts in main() function after starting a debug
session.
3.6 Touch Screen
To support resistive touch screen, use ADC to convert the voltage of X axis and Y axis, and
then use the open source tslib to map the ADC conversion result into the coordination. The
conversion result can be affected by power noise, mechanical misalignment, etc. To
overcome this issue, the tslib supports calibration function, and the calibration parameter is
stored ether in APROM or a SD card.
As mentioned in section 3.1, there are two targets in this project: emWin_SimpleDemo uses
the calibration parameter in the APROM offset 0x00040000, and emWin_SimpleDemo_SD
uses the calibration parameter results in a SD card called ts_calib. User can switch between
different targets using the pull down menu marked in the red rectangle shown below.