2009
09.02

After this comment from my multitouch article, i compiled a new kernel and flash it on my Galaxy. After a few test here the results:

one finger test:

<4>[  882.901393] x 249, y  66, z  53, finger   1, width   0
<4>[  882.923068] x 222, y  72, z   0, finger   0, width   0

two finger test:

<4>[  882.618176] x 224, y  73, z  20, finger   1, width   0
<4>[  882.641810] x 224, y  72, z  0, finger   0, width   0

three finger test:

<4>[  882.830503] x 263, y  68, z  46, finger   1, width   0
<4>[  882.854216] x 255, y  68, z  0, finger  0, width   0

four finger test:

<4>[  884.489730] x 145, y 470, z  34, finger   3, width   0
<4>[  884.511106] x 145, y 470, z   0, finger   0, width   0

This ist much freaky. The first finger will be detect, ok this is clear. Finger 2 and 3 not, but finger 4 will be detect. I don’t know why finger 2 and 3 not. Samsung give me answer, please.

If you want to test this on your mobile phone here is my boot image: boot_mt_test

14 comments so far

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  1. I dont get it: do you press 4 fingers at a time and the display only recognizes the first and the fourth finger? Is your image a normal recovery image what I can test and savely overwrite again? Then I will try it myself.

  2. It is a normal boot image, not a recovery image. Make a nandroid backup before. After the test restore the backup.

    Flash it with “fastboot flash boot image_file”. After rebooting in normal mode, open a shell in the mobile phone and type dmesg.

  3. Sorry, then I will not test it. My Nandroid-Backups aren’t working (even the backup and restore process seem fine, no apps+configs are restored) and I do not want to initialize my phone from scratch… again.

    But I am very grateful for your fundamental research for the Galaxy!

  4. you could just do “fastboot boot ” instead right? :) or have i misunderstood the fastboot syntax

  5. “fastboot boot image_file”*

  6. “In this driver, this is:
    0: no touch
    1: single touch
    2: dual touch
    3: palm touch
    7: proximity”

    So I guess starting from the fourth finger it is detected as “palm touch”.

  7. @Johan: I don’t think fastboot boot works on the Galaxy yet.

    Correct me if I’m wrong.

  8. Taking into account the comment from Pieter, I’m afraid the 4 fingers are already detected as a palm touch. Does it change with 5 or more (a bit fiddly :-) ) fingers?

    btw., wrong captcha and back button -> comment destroyed X-(

  9. Too bad. Probably the screen detects multiple fingers or at least the size of the area it is touched with, but it doesn’t send it to the kernel.

    Even this it is possible with the hardware in the Galaxy, this is hard without the support of Melfas or Samsung. You could try sending them an e-mail…

  10. I try to guess. To me the other fingers are registered in the register following the 0×10 (maybe 0×17 and 0×1e). Since 4 fingers gives palm touch I think the melfas can detect at the maximum 3 fingers (3 register). It can be good to print the dump of the registers from 0×00 to 0×27.

    Ciao Angelo

  11. [...] nicht mehr als einen Finger erkennt. Ok, den vierten Finger erkennts wieder Hier zum nachlesen: Samsung Galaxy recognize more as one finger | receptorBlog [...]

  12. The source for the samsung beholden II has just been released. This appears to have more or less the same hardware as the i7500. It contains a much more elaborate touchscreen driver. Actually the touch support seems to be exactly the same, but it contains functions to flash the firmware of the touchscreen.

    This means the touchscreen actually has configurable firmware and that multitouch will probably be possible, if samsung chooses to support it - or we can get documentation from Melfas.

  13. And it also contains a binary firmware for the i7500 and the beholden… Anyone want to try downloading their old firmware and putting this in place instead and see what happens? :)

    ( warning, you may very well brick your phone doing this )