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resistive touchscreen

toonamo

So first off i originally thought i could use an ar1100 to act as a touchscreen for my 7" HDMI lcd screen. However after trying the Vendor_04d8_Product_0c03.ics file in /system/usr/idc folder and rebooting i still can't get it too work. A lot of people can't get it to work so I figured it can't be use with android 4.3 as it stands.

 

When i plug it in the debug window shows

usb 2-1.2: new full speed USB device number 5 using fsl-ehci

input: Microchip Technology Inc. AR1100 HID-MOUSE as /devices/platform/fsl-ehci.1/usb2/2-1/2-1.2/2-1.2:1.0/input/input3

generic-usb 0003:04D8:0C02.0004: input,hidraw0: USB HID v1.11 Mouse [Microchip Technology Inc. AR1100 HID-MOUSE] on usb-fsl-ehci.1-1.2/input0

 

but the touching the panel does nothing. Not in app, or out. The screen works fine on my windows machine.

 

My question is how can i interface a 4 wire resistive touch screen? I don't mind if i have to use i2c or whatever it takes but i don't know where to start. i noticed some people are useing the lvds as a hdmi out to go to laptop screens but no one ever discusses getting the touchscreen to work. Or at least in any writeup/ tutorial i could find.

 

Some background on my project is that i want to use this to have a 7" touchscreen in my vehicle that runs android software and also software i will create to control electronics in the car. I have everything i need except for a touchscreen.

 

Linux won't work very well because it's not touchscreen friendly at the moment. (pop up keyboard, email apps, etc.) Maybe once ubuntu makes thier phone software it will be a better option but for now I need android to work.

 

Any ideas how to get a 4-wire resistive touch screen to work with android? I can compile from source if i have to i just don't know what to edit.

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    Resistive touch screen just needs two ADCs that detect two resistance values (for X and Y). Resistance values are then converted to screen coordinates by means of calibration data (to get calibration data, user has to launch a procedure that shows crosses in the four corners of the screen).

    That said, the connection circuit is easy to implement

     

    microcontroller - Resistive Touch Screens - Electrical Engineering Stack Exchange

     

    On Linux (and hence android) you can find several touch drivers. The most widely used is tsc2004. You can have a llok and start from there

     

    Ambrogio

  • 0 in reply to amgalbu

    Thank you Ambrogio. I understand the x and y aspects of a touch screen. I just don't understand how to get this data to android. A driver would mean there is a device to connect to convert the data to something the android understand by utilizing the driver. When i try to google touchscreens all it shows is a 10 inch and a 5 inch with a capacitive sensor. My problem is i can't fit a 10 inch in my dash and 5 is just too small.

     

    Does anyone know what i need to do in order to connect a 4 wire touch sensor to the riotboards gpio and what source to edit in order for it to work? Or perhaps a usb device that works with android since the ar1100 does not.

     

     

    edit: well i can't figure out how to communicate with the ar1100 when it's connected to the android but i did figure out that i can send commands to emulate touch/ tap events from the shell

    input tap 200 622

     

    so for now i am going to use a arduino to "read" touch events and then send them to the shell. Once i figure out how to edit the source to read the sensor over gpio then i will modify the source to read the events directly. For now i will use the debug port

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  • 0 in reply to amgalbu

    Thank you Ambrogio. I understand the x and y aspects of a touch screen. I just don't understand how to get this data to android. A driver would mean there is a device to connect to convert the data to something the android understand by utilizing the driver. When i try to google touchscreens all it shows is a 10 inch and a 5 inch with a capacitive sensor. My problem is i can't fit a 10 inch in my dash and 5 is just too small.

     

    Does anyone know what i need to do in order to connect a 4 wire touch sensor to the riotboards gpio and what source to edit in order for it to work? Or perhaps a usb device that works with android since the ar1100 does not.

     

     

    edit: well i can't figure out how to communicate with the ar1100 when it's connected to the android but i did figure out that i can send commands to emulate touch/ tap events from the shell

    input tap 200 622

     

    so for now i am going to use a arduino to "read" touch events and then send them to the shell. Once i figure out how to edit the source to read the sensor over gpio then i will modify the source to read the events directly. For now i will use the debug port

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