Touchpad as a tablet?

Discussion in 'General Hardware' started by NetRyder, May 31, 2003.

  1. NetRyder

    NetRyder Tech Junkie Folding Team

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    Ok folks...there's something I wanted to clear up. As some of you know, I got my laptop around a month and a half ago. A friend in school also bought one around a month ago.

    Now he was asking me if it's possible to use the touchpad as a tablet, using some kind of stylus for the purpose. What he means is: is it possible to write on the touchpad using a stylus of such that the touchpad recognizes the input?

    Both of us have Synaptics touchpads, and I don't think it's possible to do any such thing. But I just wanted to make sure from you folks. Any comments on the matter? Do you think it can be done somehow?
     
  2. Zedric

    Zedric NTFS Guru Folding Team

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    Not being an expert on touchpads I'd say no. I believe they are too small and have too low resolution. But I'm not an expert. :)
     
  3. Taurus

    Taurus hardware monkey

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    i don't think it's a matter of resolution. i've used a synaptics touchpad on an inspiron 8100 and when it can detect your moving the cursor one pixel on a 1600x1200 screen, that's pretty sensitive. more than enough to recognize handwritten text.

    but i really have no idea if there's any program out there that changes the role of the toughpad. if there isn't anything, then it's probably not possible. the hardware might be designed so that that kind of touch recognition isn't possible (tracing the movement to complete a figure).
     
  4. NetRyder

    NetRyder Tech Junkie Folding Team

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    Thanks for the replies, guys.
    According to this page (http://www.synaptics.com/products/touchpad_faq.cfm), it says:

    Doesn't it seem like it should work with any kind of good electrical conductor then? Maybe a stylus that's made of complete metal that's a good electric conductor?

    What do you think? :)
     
  5. Comptech

    Comptech Guest

    I don't think it would ever work. As your clip said"It is controlled by a ASIC chip" ASIC as you probally know is short for application specific intergrated circuit. The controller [ASIC] is made to do that one thing, so all the software in the world would not help. The only possibility would be to reprogram the ASIC somehow to do what you want it to do. And one more catch, 99% of the ASIC I have dealt with are encrypted!
     
  6. NetRyder

    NetRyder Tech Junkie Folding Team

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    Yes, but what we want it to do is exactly the same thing as it's doing now. We just want it to be able to track stylus movements instead of finger movements ... no need of any changes in precision or functionality.
     
  7. Comptech

    Comptech Guest

    That's what needs to be changed, it only tracks the movement so it knows where you are on the desktop, the only command it sends is the click on the item you are on. If you could reprogram the ASIC to record the total movement, then you would have what you want. Another consideration is if the ASIC even has enough KB to do this.
     
  8. NetRyder

    NetRyder Tech Junkie Folding Team

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    There is a little utility on the site called Synaptics Sketch that allows me to draw using my finger on the touchpad. The "pen" moves as my finger moves along the touchpad, so it does seem like it's recording total movement. Any chance some other material could be used to produce the same effect as the finger (since the finger isn't as easy to control as a stylus, for example)?

    Is there more to it than just electrical conductivity?
     
  9. Comptech

    Comptech Guest

    I will try to explain this a little easier, the asic is probally a 16kb chip. As you move your finger it writes to the next memory cell and clears a previous one. A good example would be to open excel, fill in the boxes as you wish to make a basic outline of a shape. Then hit close and when it asks you to save say no. Now go back to excel and try to open your outline of a picture,guess what? It's not there. This is the problem with the touchpad.
     
  10. NetRyder

    NetRyder Tech Junkie Folding Team

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    Ah, I see what you're saying. So then, as I initially expected, it's probably not possible. :(
     
  11. Comptech

    Comptech Guest

    You posted while I was typing, if you can do that, then there is a small chance that modifing their software could work if you can find the code and also find a way to save it. I would be interested in finding a way to do this. Let me look into it a little more, I have a old dell laptop here with that touchpad. If the ASIC is not encrypted, there is a chance of finding a way to save it.
     
  12. NetRyder

    NetRyder Tech Junkie Folding Team

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    You might want to look at this page:
    http://www.synaptics.com/support/downloads.cfm

    It has the programming API's for the touchpad as well.
    Thanks a lot for looking into it. I was just curious, but it would be really awesome if there was some way of doing this. :)
     
  13. NetRyder

    NetRyder Tech Junkie Folding Team

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    From another Synaptics document:

    Does that mean a conducting stylus-like object (one that's possibly made completely of metal) would be detected as a "finger" as well? If so, that's all we would need, right?
     
  14. Taurus

    Taurus hardware monkey

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    they way i see it, the touchpad chip is sending signals just like a mouse. the rest of the computer thinks you're using a mouse. so when you move your finger across the pad, it thinks you're dragging hte mouse... and when you pick your finger up? the curser is still there... it thinks the mouse is static.

    my point is that the hardware would have to able to report when there is nothing touching the pad (after you finish a letter)... which it simply might not be programmed to do.
     
  15. Comptech

    Comptech Guest

    Tarus is right, not programed to do. And to find a interface that could program it to work would be fruitless, because if you could find it, the ASIC would be to small to handle it.
     
  16. Comptech

    Comptech Guest

    By the way, how many posts does it take to get past the beginner thing? I want one of those title things like ntfs loser or wannabe type things!
     
  17. ElementalDragon

    ElementalDragon The One and Only

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    Comptech, go into the user cp, then edit profile. to change what it says below your avatar, you have to edit the "Custom User Text"
     
  18. NetRyder

    NetRyder Tech Junkie Folding Team

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    Wow Comptech ... you've been a member for a real long time. :)
    Back to the topic: I guess I have to drop the idea then. As I said, I didn't expect it to be possible anyways.
     
  19. Taurus

    Taurus hardware monkey

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    lol :p