davedarkoAt first I thought I would slap an n-channel MOSFET to an attiny85, switch low-side (as in cut off the ground of PI) and call it a day. Then @Alex said high-side switching makes more sense, but complicates things. For a start you need a p-channel MOSFET instead AND to switch it off you need an extra transistor when your Attiny runs on 3.3V to achieve the voltage level that you're switching.
I learned a lot yesterday just by talking over whatsapp with Alex, while we were kind of distracted by the live stream of the "unexpected maker". In the end I found a chip called TPS22917, that Alex waved through as a "possible/passable candidate". This way I don't need a mosfet and a transistor etc.
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Thanks for the info
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Yep the TPS ones are nice. Have used the TPS2051. and TPS27082.
A cheaper one (diff. brand) is the sy6280aac. They're called high side switches in general, the tps series was introduced for usb power switching iirc.
Edit: the sy one I isn't current capable enough for your rPi anyway. Whatever, the TPS switches are really nice to work with.
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Hmm, with a part like this, it should be easy enough to do it. Maybe I will give it a go myself, for another version of #Ye Olde Nowt. I think you could even get away with something cheap like attiny9.
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downgrading is always an option :) I thought about having an I2C connection instead of a signal pin -> so an attiny85 would be handy for developing. Regarding the pins I could still switch to an attiny13 afterwards, if space is enough.
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