• Iteration 1: first board

    Tykhon05/15/2024 at 16:29 0 comments

    Heya! So, in the spirit of sprinting so fast that I forgot all (two) rules of good PCB design that I ever knew, I sat down some time last week and drafted the very first PCB design for the project. Ain't she a beauty?

    ...I don't remember much of what has followed, but somewhere between 4 and 5AM I must've ordered it into production because mere 4 days later it showed up at my doorstep. Somewhere between those two events I started writing code for it, which is now up on the Github along with the schematic-PCB-notes and everything. Anyway, with the board all starry-eyed and begging to be soldered, felt only fair to oblige:

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  • Iteration 0: first touch

    Tykhon05/06/2024 at 19:13 0 comments

    So I had the idea for this project for a whole of 3 days, and you know how sometimes you just... get an itch to do the thing... Well, yesterday I did the thing.

    The thing was - run a single-cell button off my Pi Pico (okay, fine, it's Pimoroni's Pico Lipo - but it's pin-compatible so it still counts! And it still has the shitty ADC). I did that, and managed to see a swing of 0.8V - 1.6V between notouch-touch. nice.

    Basically, this proves the concept - you CAN swing a line at 10MHz, 25% duty PWM (dear lord whomever made RP2040/'s IO deserves a medal, "PWM on any and all pins? Go for it, we gotchu."), then feed it into ADC, and read back measurable difference between the sensor being touched or not touched.

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