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I have an old wacom tablet at home, its really big and I'd like to use it but I've lost the pen for it. It uses pens with passive LC circuitry. The board creats an EM-field (I can see it on my oscilloscope) with which the pen interacts and the board can deduce information from the interaction. I looked up the patent and its basically just a coil parallel to a couple of caps.

Is it possible to make a simple LC-pen that would interact with the board simply by trying without more knowldege about the board and pen?

schematic

simulate this circuit – Schematic created using CircuitLab

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    \$\begingroup\$ If it is anywhere near any of the tablets I have worked with in the last 10+ years, it contains something similar to an rfid chip that gives back an id, and if its one of the more expensive ones, information about pens tilt, buttons pressed and pressure. On my current tablet I have three different pens and a mouse that all have their own ID. I have never seen any that doesn't give any digital information back. \$\endgroup\$
    – PlasmaHH
    Nov 13, 2014 at 16:30
  • \$\begingroup\$ its a realtively old one seen here zbrushcentral.com/… \$\endgroup\$
    – Flying Swissman
    Nov 13, 2014 at 16:34
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    \$\begingroup\$ That one has tool identification (front tip, back tip, mouse), multiple buttons (pen and mouse), and 1024 pen tip pressure levels and 2540 lpi (compare to 2048 pressure levels and 5080 lpi of the current intuous). I would be really suprised if they could manage to do that without any silicon in the pen/mouse. Do you have the mouse for it? You could look into it. I might have one of them from that model around somewhere, when I find it and remember this post... \$\endgroup\$
    – PlasmaHH
    Nov 13, 2014 at 17:28
  • \$\begingroup\$ Thanks! problem is I can't find mouse or pen or anyhting at the moment and I don't want to just throw it out. I thought maybe it would be possible to make a primitive pen, but it seems the pen is more intelligent then I thought. \$\endgroup\$
    – Flying Swissman
    Nov 13, 2014 at 17:33
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    \$\begingroup\$ I am sure there are pens out there that are just waiting to be sold... \$\endgroup\$
    – PlasmaHH
    Nov 13, 2014 at 21:04

1 Answer 1

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If I am right, then the display works with capacitive , which means all it needs to complete the loop of the circuit to register a touch. So a basic circuit should be enough with your old stylus specified voltage power supply.

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