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Touchscreen Calibrator.apk crashes on SAMA5D4

Posted: Fri Aug 17, 2018 12:58 am
by yechielco
Hi,

I am using the Android4SAM 4.4 prebuilt binaries with the TM4301 LCD.
The touchscreen is expected to be calibrated by the user after the first android boot so when I touch the screen the pointer is shown with a bright dot.

I have built the Anroid source code for
I looked for a way to calibrate the touchscreen. I have found the out/target/product/sama5d4/system/app/Calibrate.apk.
But it will always crashes in the end of calibration.
A further look into the adb logcat prints showed that the onTouch() listener gets ZERO X and Y values.
In the apk source code I could see that it tries to read those values from
/sys/module/at91_adc/parameters/rawX
/sys/module/at91_adc/parameters/rawY

But these files will always show zero no matter the touchscreen presses.

What is the proper way to calibrate the touch then?