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From: The Natural Philosopher <tnp@invalid.invalid>
Newsgroups: comp.sys.raspberry-pi
Subject: Re: RP2040 zero
Date: Tue, 6 May 2025 14:25:40 +0100
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On 06/05/2025 14:19, Theo wrote:
> Andy Burns <usenet@andyburns.uk> wrote:
>> the BusPirate folks had issues with their BP5XL boards and needed to
>> junk a batch, I see that redesigned as the BP6 it's now on sale ...
> 
> Yes, that's the kind of application where it's a problem.  You attach GPIOs
> to random stuff and intend to probe what's there.  That means you flip
> through the internal settings for input/output/pullup/pulldown and listen
> out to how the input changes.
> 
> The leakage affects that kind of application badly (input pins should be
> high impedance but they aren't here) but if you are putting the chip in a
> board where you already know what's on the other end of the pin, you can
> design the circuit appropriately.
> 
> RPis are more likely to be used in situations where you take the MCU and
> plug in and out random things onto the pins which are affected by it,
> compared with other MCUs where they only ever get put on vendor PCBs where
> everything is predetermined in the schematic.  So it's really a hobbyist
> focused problem rather than a wider problem.
> 
> Theo
All my Pis end up on my design of PCB where stuff is either disabled or 
its strictly controlled

I cant see why anyone would enable an input pin and leave it floating. 
Its simply bad design


-- 
“It is hard to imagine a more stupid decision or more dangerous way of 
making decisions than by putting those decisions in the hands of people 
who pay no price for being wrong.”

Thomas Sowell