• State Resolved
  • Locked Locked
  • Replies 4 replies
  • Answers 1 answer
  • Subscribers 97 subscribers
  • Views 519 views
  • Users 0 members are here
Support feedback
Options
Options
Related

This thread has been locked.

If you have a related question, please click the "Ask a related question" button in the top right corner. The newly created question will be automatically linked to this question.

PROCESSOR-SDK-AM437X: 5-wire touchscreen support

user5926475
Expert 1270 points
Part Number: PROCESSOR-SDK-AM437X
Other Parts Discussed in Thread: AM4379

Hi,

We designed a custom board to support touchscreen  with 5 general-purpose ADC0 channels.in Am4379. There are only 4 wire TSC in DTS:

&tscadc {
    status = "okay";
    tsc {
         ti,wires = <4>;
         ti,x-plate-resistance = <200>;
         ti,coordinate-readouts = <5>;
         ti,wire-config = <0x01 0x10 0x23 0x32>;
         ti,charge-delay = <0x800>;
   };
   adc {
         ti,adc-channels = <4 5 6 7>;
   };

};
We use 5 inputs (ADC0_AIN0, ADC0_AIN1, ADC0_AIN2,ADC0_AIN3,ADC0_AIN4)  connected to touchscree 5 pins respectively.( Is there an error in Technical_Reference_Manual(Rev_H) that 5-wire TSC with 3 general-purpose ADC channels in 11.1 Page 1794?).

I want to know how to modify the DTS, and how to config kernel with TI touchscreen support. Our SDK is sdk-05.01.00.11. Is there any document about TSC config to reference?

Best Regards,

  • 0
    TI__Guru** 103210 points

    Hello,

    There are 8 ADC inputs. If using an input for the touchscreen, we typically call it a touchscreen input. If using an input for something other than touchscreen, we call it a general purpose input. So if we are using a 5-wire TSC, then there will be 3 remaining channels that can be used for general-purpose applications.

    I link a lot of 5-wire touchscreen information in the thread ADC voltage in 5-wire resistive touchscreen.

    Regards,

    Nick

  • 0 in reply to Nick Saulnier
    Expert 1270 points

    Nick,

    Thank you.

    Does our SDK-05.01.00.11. support 5-wire tourchscreen and need not any patch ?

    The linux version is 4.14.67

    Our DT file about tsadc is:

    &tscadc {
        status = "okay";
        tsc {
             ti,wires = <5>;
             ti,x-plate-resistance = <200>;
             ti,coordinate-readouts = <5>;
             ti,wire-config =  <0x00 0x11 0x22 0x33>;
             ti,charge-delay = <0x400>;
       };
       adc {
             ti,adc-channels = <5 6 7>;
       };
    };

    The connections between ADC0 to touchsceen is:

    AIN0--XP,  AIN1-- XN, AIN2 -- YP, AIN3 -- YN, AIN4 -- WIPER

    Best Regards,

  • 0 in reply to user5926475
    TI__Guru** 103210 points

    Hello,

    As per my link in the previous post, TI does not explicitly test 5-wire touchscreen on each SDK. We have not had any customers post questions about 5-wire touchscreen on SDK 5.1, so it may or may not work without patches to the code. If you run into issues, we can help you debug and provide patches if needed.

    Regards,

    Nick

  • 0 in reply to Nick Saulnier
    Expert 1270 points

    Nick,

    Many thanks for your support!

    It  works well now.

    Regards,