using mutable isntruments tvs diodes 

use 2X5 pin arrangement for power supply 

//Power supply protection 
series diode protection
introduces power drop 
you can use a schottky diode 

but what he reccomends instead is to use a polyfuse protection instead 

you have a polyfuse in series, and also a diode connected 
he uses
SMD0805-010-24V
the diode can be any cheap power diode

google polyfuse protection 

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using the pico minimum viable board 

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8V for gates

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a way to market it this would be don't tell people that literally
keep the mysteriousness
the mystique

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for PCB one all ground, other side connections 
all the connections have vias to ground

use a decent track width for power .5mm
but for everything else you can use pretty small traces

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to step the voltage up on output of rp2040 
use a CMOS chip 
CD40106B
or HC etc. - as long as the numbers are the same 
40106

use a regulator
L78L08 
12V to input 
outputs 8V 
put a capicator to ground to help smooth out the voltage

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pj398SM

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