Linux/PROCESSOR-SDK-AM335X: Touchscreen issue

user4835699

Tool/software: Linux

I use the version is ti-processor-sdk-linux-rt-am335x-evm-03.02.00.05-Linux-x86-Install.and the qt version is qt5.4.1 the tslib version is 1.4.I had Calibrated screen.create the file is pointercal is normal. but I run the ts_test,Touch screens are sometimes accurate and sometimes offset.

over 6 years ago

0 Biser Gatchev-XID over 6 years ago

TI__Guru**** 393215 points

Please describe your hardware. Is this a custom board? What is the touchscreen type? How is it connected?

0 user4835699 over 6 years ago in reply to Biser Gatchev-XID

Prodigy 150 points

I use BBBlack now, and the touchscreen type is resistive touch screen，4-wires. the resistive touch screen is base on the am335x_evm board.

0 Nick Saulnier over 6 years ago in reply to user4835699

TI__Guru** 105480 points

I am sorry for the delayed response.

Please attach the command line output. Could you provide more details about the error behavior you are observing? e.g., what does "sometimes accurate and sometimes offset" mean?

TI's documentation for recalibrating a touchscreen is here.

Regards,

Nick

0 user4835699 over 6 years ago in reply to Nick Saulnier

Prodigy 150 points

I run the ts_calibrate,and run the ts_test next time.the touch screen is accuracy .put off the power.

I put on the power and run ts_test,the touch screen may be accuracy.

repeat the above step.

the touch screen may be inaccuracy.

0 Nick Saulnier over 6 years ago in reply to user4835699

TI__Guru** 105480 points

1) I am going to list debug details based on your post. Please correct anything that is wrong.

a) The touchscreen is accurate after running ts_calibrate

b) if you remove power to the board, and then reboot the board, sometimes the touchscreen gives accurate results. However, sometimes after the board has been powered off and then powered back on, the touchscreen does not give accurate results.

c) Even when the touchscreen is not giving accurate results, it still registers a touch somewhere on the screen when you touch the screen. The touch is just registered in the wrong part of the screen.

2) Did you disable Weston? If you did not disable weston, then I think you would need to use ws-calibrate.rules for your touchscreen settings rather than the pointercal file. If you are using Weston, please look at section "Weston based Graphic System" instead of section "Non-Weston based Graphic System" in TI's documentation for recalibrating a touchscreen.

Regards,

Nick

0 user4835699 over 6 years ago in reply to Nick Saulnier

Prodigy 150 points

"Even when the touchscreen is not giving accurate results, it still registers a touch somewhere on the screen when you touch the screen. The touch is just registered in the wrong part of the screen" the mean of this sentence is the touchscreen is wrong? why the touchscreen gives accurate results sometimes?

0 Nick Saulnier over 6 years ago in reply to user4835699

TI__Guru** 105480 points

Please read my entire post. Please respond to everything in 1) and everything in 2). I cannot help you debug your problem if you only give me vague descriptions like "sometimes the touchscreen is inaccurate".

Regards,
Nick

0 Nick Saulnier over 6 years ago in reply to Nick Saulnier

TI__Guru** 105480 points

I am going to mark this thread resolved. Reply if you want to continue the discussion.

Regards,
Nick

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Linux/PROCESSOR-SDK-AM335X: Touchscreen issue