Sponsored by JLCPCB ($2 for 10 Boards): https://jlcpcb.com
One potentiometer to control the waveforms on two different MOSFETs. Colour codes needed for the pot, buck and boost converter ranges. Arduino's map() and constrain() functions employed. Oscilloscope testing with a tricky triggering problem. Final testing on the Muppet 2 breadboard - and ultimately, success ๐Ÿ™‚

By Julian

Youtuber, shed dweller, solar charge controller aficionado

16 thoughts on “One pot – two fets – muppet 2”
  1. Avataaar/Circle Created with python_avatars FindLiberty says:

    NOICE! It's a keeper.

  2. Avataaar/Circle Created with python_avatars Mike Poirier says:

    Very useful. Thanks so much.

  3. Avataaar/Circle Created with python_avatars Mick Thorpe says:

    Julian ?! ALT, ALT CHOP, ALT TRIG or ALTERNATE will trigger fron either channel. How long have you been using a scope?
    Keep up the good work.
    Mick T

  4. Avataaar/Circle Created with python_avatars lez briddon says:

    i love my old valve scope, one knob pre function, looks like the dash of a space shuttle, change from trigger ch1 to trigger ch2 with one click…

  5. Avataaar/Circle Created with python_avatars Urban Resourcfulness says:

    Awesome work as usual Julian!
    I would have loved to have seen your analog voltmeter across the lamp, to visually stimulate my 'geeky-ness' and see exactly what the muppet2 is outputting as you go through the ranges.
    Cheerio,
    Barry, from Canada

  6. Avataaar/Circle Created with python_avatars Corn Julio says:

    Will there be a DCOI v2 video? Is it still viable at all? It exists only to find a purpose for Non-LL Mosfets, isn't it? So people should just use an LL Mosfet in the first place, right?

  7. Avataaar/Circle Created with python_avatars Robert Langford says:

    You have a gap between the two ranges so your Uno doesn't know what to do between the two ranges as it passes from one range to the other.

  8. Avataaar/Circle Created with python_avatars Paul Grimshaw says:

    It's probably clear anyway, but the first map function didn't drop its output to zero above 341 input. It just kept on increasing in proportion. So after 341 mapped to 01ffh it mapped 342-511 to 0200h-02fdh. The PCM generator just chopped off the top bits, effectively subtracting 0200h. That's why the constrain worked, preventing the output increasing above 01ffh.

  9. Avataaar/Circle Created with python_avatars Tony Eezi says:

    Agree with the unnecessary '/2' but also am I reading this right, are you trying to assign a value of between 0 and 511 into an 8 bit register?

  10. Avataaar/Circle Created with python_avatars Tom George says:

    Hi Julian, great video.
    BUT can you exercise the practice of TURNING your project OFF before disconnecting or reconnecting components. A bad example to new project constructors.

  11. Avataaar/Circle Created with python_avatars MD4564 says:

    I had a potentiometer that started to smoke on me.

  12. Avataaar/Circle Created with python_avatars Joe's Model Kits says:

    AAAH, I get it!, Basically what you are saying is that you don't get a brown pen in the Sharpie selection pack. Thank heavens I was not as confused as I thought.
    Have a great day and many thanks for the videos,
    Joe

  13. Avataaar/Circle Created with python_avatars flagpoleeip says:

    when you say it should trigger on either of the two channels 'whichever is active' what do you mean by active?
    this is a rhetorical question.

  14. Avataaar/Circle Created with python_avatars flagpoleeip says:

    please stop calling them potties. it sounds horrible

  15. Avataaar/Circle Created with python_avatars St3venAU says:

    Interesting stuff. It generates a high pitch sound when you have it in boost mode. The volume of which increases to a fairly unpleasant level at max boost.

  16. Avataaar/Circle Created with python_avatars Milene De jong says:

    great video again julian..

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