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Original question:

TSC2007: PENIRQ signal is generated interrupt signal all the time

TSC2007: PENIRQ pin kept triggering

Bill Shih
Prodigy 50 points
Part Number: TSC2007

Hi TI,

We are now developing Android A11 using kernel version4.19

After merging the tsc2007 driver from https://www.ti.com/tool/TSC200XSW-LINUX and booting, PENIRQ is kept high.

And then after one touch on panel, PENIRQ kept triggering, as shown below, even without touched again or pin x+, x-, y+, y- input schematics removed.

Do you have any suggestion for this situation?

Below is the PENIRQ waveform when touch panel long pressed.

  

Thank you

  • 0
    TI__Mastermind 22950 points

    Hi Bill,

    Can you please provide a current schematic? 

    There are two programmable PENIRQ values at 50kohms and 90kohms. Have you tried switching this value?

    Regards,

    Aaron Estrada

  • 0 in reply to Aaron Estrada
    Prodigy 50 points

    HI Aaron

    Our schematics is as below:

    I am trying to change pullup resistor with

     err = tsc2007_xfer(ts, 0xb1);

    but kept receiving error -107.

    Do you have any suggestion?

    Thanks

  • 0 in reply to Aaron Estrada
    Prodigy 50 points

    Hi Aaron

    I tried to config penirq as gpio input in devicetree and found that irq could maintain high when no touch.

    But when long touch happen, the irq waveform shows like below 

    Is it correct? Shouldn't it be low without the spikes?

    Further more, when finger release from touch panel, it will look like this:

    Are the temporary down spikes expected?

    I failed to config switch pullup resistor. Should there be other commands needed before config that?

    I think our i2c is working because I could get the xy value when panel is touched.

    Looking forward to your suggestion.

    Thanks

  • +1 in reply to Bill Shih
    TI__Mastermind 22950 points

    Hi Bill,

    The first image where the long press is happening is actually expected and is explain in this PENIRQ App Note. However, I can't seem to figure out why there are low going transients when the finger is released (second image). I cannot explain this but I would assume these are just glitches in the PENIRQ signal. 

    I recommend going through the above App Note on the PENIRQ feature. As for switching the pull up resistance, there should not be any other commands needed to send before doing so. 

    Regards,

    Aaron Estrada