Re: RP2040 zero

On 06/05/2025 11:43, Theo wrote:

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

Ah. But the boards I am talking about have allegedly pukka RP2040 chips on them
https://www.aliexpress.com/item/1005008120181701.html
It's OK...I take it no one here has used them. Well I'll report back when I have. So far all I did was plug one in and  fire up with bootselect button pushed. It looked like a Pico does.
Lightweight too. 1.75g
--
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Thomas Sowell