Re: RP2040 zero

Andy Burns <usenet@andyburns.uk> wrote:

The Natural Philosopher wrote:
 

I got some of these seriously cheap from Ali Express, They are
essentially a PI PICO on a much smaller board with fewer  accessible pins.
 
Has anyone used one?

When the PICO2 came out, I bought a couple of PiMoroni 2350 boards, both
smaller than official PICO2 boards, one with USB-C and fewer pins, one
with full set of pins but no USB port on-board ... life intervened so
done nowt with them ... I remember hearing there's something b0rked with
I/O on the 2350s in general, not sure if it's just edge cases or
generally fucked?

https://hackaday.com/2024/09/20/raspberry-pi-rp2350-e9-erratum-redefined-as-input-mode-leakage-current/

basically if you want a pulldown on an input pin there's chunky leakage
current.  That can also affect external circuitry that isn't expecting it,
eg if you have a resistive divider as the leakage could drag the voltage
down.  You can end up with I/Os getting stuck halfway and effectively
latching old values.

That could cause some issues if you're doing a drop in replacement for a
RP2040 but if you use stronger external pullup/pulldowns it should avoid the
issue.

It looks like they haven't done a respin to fix it thus far.

Theo