Keypad uses a PIC’s built in capacitance functionality

[Giorgos Lazaridis'] most recent project was to build a capacitive touch pad. Since he’s using a PIC 16F1937 it will be relatively easy. That’s because it has a 16 channel capacitance sensing module built right in. But there are still some design considerations that make the development a bit touching.

This isn’t the first time he’s worked with capacitance sensing. Through past experience he has found that it is very important to position the microcontroller as close to the button pads as possible. Because of this, the chip is soldered on the back of the PCB used for the keypad itself. Because he’s hand soldering vias, he also used some foam tape to raise the button pads just a bit. This way they will be flush with the acrylic overlay, which cannot sit flat on the board due the via solder joints.

Check out the video after the break to hear [Giorgos] walk us through the project.

7 thoughts on “Keypad uses a PIC’s built in capacitance functionality

  1. @szczys
    By “touching” you of course mean “touchy”, so that the pun makes sense.

    As an aside, do HaD authors lack the ability to edit posts, or is it policy not to? Often I see egregious errors in posts and apologies made by authors in the comments, but I don’t think I’ve ever seen a correction made.

  2. “He just kept talking in one long incredibly unbroken sentence, moving from topic to topic, so that no one had a chance to interrupt; it was really quite hypnotic.”

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