7400 competition entry: Capacitive Sensing, the Hard Way

Posted on Wednesday, September 28th, 2011 in 7400 contest by Ian

Here’s an entry in the Open 7400 Logic competition: Capacitive Sensing, the Hard Way – 16 Channel Capacitive Sensor, RS232 Out

This entry was posted on Wednesday, September 28th, 2011 at 2:51 pm and is filed under 7400 contest. You can follow any responses to this entry through the RSS 2.0 feed. You can skip to the end and leave a response. Pinging is currently not allowed.

10 Responses to “7400 competition entry: Capacitive Sensing, the Hard Way”

  1. Henrik Brix Andersen says:

    Really cool and clean project – and very well documented!

  2. Rohit de Sa says:

    You are God! Were you bored with your life to take such a project up? :-P Awesome!

  3. Bertho says:

    No, I wasn’t bored at all. I was already experimenting with capacitive sensing when the contest came on. Just went a bit into over-engineering mode. Took effectively only few days to design; a bit more to build, though. Actually, I think most time went into documenting.

  4. Chris says:

    Stunning mixed signal design, good write-up and retro RS232 serial port too! Not taking the easy way out with a logic level USB uart. A prizewinner in my eyes!

  5. Alvaro says:

    Very good :) The best one so far, IMHO.

    I’m to compete too, but my chips have not arrived yet. Expect some competition on this, I’m also focused on capacitive properties … :) and in a tutorial-style design.

    Your documentation is very very good. A great work!.

  6. Troy says:

    Thanks for posting your insite into capacitive touch. Really interested. I am convinced that Apple has a patent impeding hover based touch interaction from satisfying a huge demand; it would be nice for the diyers to get an early chance to play with it.

  7. Doug McClelland says:

    OK newbies’s you remind me of my not to early days as a EE at NASA. I would hand draft 7400 logic schematic for interfaces to mini- computers on a drafting table. Then I would wire wrap the design using a Gardner-Denver wire wrap tool with # 30 gauge wire. As serial to parallel interfaces for the TRS80 could cost $100 or more, so I built my own. I used 2 74LS96 shift registers and some start and stop logic to drive a ASR 35 teletype to print out my program listing. The TRS80 had a 44 pin bus connector on the side
    I had some address decode logic to parallel load the 8 bit data into the pair of 74LS96 registers

  8. Mianchen says:

    I wish I were knowledgeable enough to join the contest! I have just started again in electronics which I have left behind 15 years ago as a hobby. //cry

    • Bertho says:

      Do not despair, you do not need to be versed in all aspects to compete. The simplest of ideas are often the funniest.

      Then, you should know that I also need to do a deal of reading up on the chips at hand to get a design to play the way I want…

  9. Paul says:

    Hey Guys – I know this was over 4 years ago, but it looks like the domain expired. Do you have a repository of this stuff somewhere else accessible?

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