2
\$\begingroup\$

I'm looking to include 50-100 capacitive-touch sensors in a project. I've found these SPI 12-key capacitive touch sensors. Would it be reasonable to use several of these for such a project, or is there a more natural solution?

I'm building a chessboard-like "grid" with 7x7-10x10 touchable squares, ca 3x3cm.

\$\endgroup\$
  • \$\begingroup\$ Can some cheap touchscreen for kiosks help? \$\endgroup\$ – zoonman Aug 6 '18 at 20:27
  • 1
    \$\begingroup\$ What sort of physical touch sensors do you have in mind? Glass screen? Metal contacts? Something else? \$\endgroup\$ – duskwuff Aug 6 '18 at 20:33
  • \$\begingroup\$ @duskwuff My primary plan is copper contacts under a PMMA sheet, so that I can light the surface up. \$\endgroup\$ – Anna Aug 6 '18 at 20:37
  • \$\begingroup\$ Not a full answer, but I wouldn't recommend any solution involving the MPR121. That part was discontinued by NXP in 2015 -- Adafruit is probably building boards with old stock. \$\endgroup\$ – duskwuff Aug 6 '18 at 20:44
  • \$\begingroup\$ Thank you @duskwuff , I didn't know. Is the disadvantage to using discontinued parts that it would be hard to order new ones? Anything else I'm not realising? \$\endgroup\$ – Anna Aug 6 '18 at 20:45
5
\$\begingroup\$

With that many active zones, you're going to want to think about matrix methods rather than completely individual electrodes. Here's a relevant application note from Freescale:

Designing Touch Sensing Electrodes

\$\endgroup\$

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.