Hi there.
I need some information to find out what is happening with some os my resistive touchscreens.
I have the following issue: after a couple of month of normal usage for my own virtual terminal, the touchscreen stops responding.
After all of the test that we made, always have the very same problem: the y-axis circuit in the touchscreen is open (there´s no resistance measurement).
Do you have any idea about this problem? I have the very same circuit that you have in almost all of your demo circuits…
Please, any ideas will be good for us to keep researching…
Regards.
Martín.
Dear Diego, thanks for your quick reply.
the circuit gets open inside the touchscreen.
The cable, the PCB and the display keeps safe.
Also, the display and the touchscreen are separated items that gets stick together in manifacturing process.
We have different models for our VT, 7in and 10.4in and it inly happens in 10.4in…
Dear @MartinAused, thanks a lot for using the Toradex Developer Community.
Do you know where the circuit get interrupted? is it on the display, cable, PCB?
Did you try to use your board with a different display, to make sure the issue is not related to poor display quality?
Dear @MartinAused
Try to ensure whether the touch screen or the Colibri module is broken. This can be done by simply replacing the Colibri T20 of a working vs. a non-working system.
- If the Colibri is broken, my first assumption would be that it might be due to an electrical damage caused by ESD. In this case you should make sure that ESD voltages are properly conducted from the display frame to the shield, and if required add ESD protection diodes to the 4 touch signals.
- If the touch itself is broken, it is most probably a mechanical issue.
A resistive touch sensor is pretty simple - two resistive foils which you connect at the position where you press with your finger (there’s many explanations about the resistive touch technology in the web, here’s one explanation on AnalogueDialog). You can use a simple ohm-meter to verify which part of the touch sensor is broken.
Regards, Andy
Dear Andy.
I´ve already replace the Touchscreen and the terminal with the new touchscreen is working fine.
It´s the touchscreen the one that´s broken.
I was trying to find out if there´s some circuit inside the Colibri module that may force some current or maybe voltage and that broke the touchscreen.
I think that´s not an option, so I will keep searching for mechanical issues that may force the touch panel…
Thank you and all of your team.
Regards.
Martín
Dear Andy.
I´ve already replace the Touchscreen and the terminal with the new touchscreen is working fine.
It´s the touchscreen the one that´s broken.
I was trying to find out if there´s some circuit inside the Colibri module that may force some current or maybe voltage and that broke the touchscreen.
I think that´s not an option, so I will keep searching for mechanical issues that may force the touch panel…
Thank you and all of your team.
Regards.
Martín
