Re: More WiFi mischief in Bookworm

bp@www.zefox.net wrote:

The Natural Philosopher <tnp@invalid.invalid> wrote:

On 17/06/2025 16:08, bp@www.zefox.net wrote:

Turning wifi back on caused a momentary
dip to 5.06V which recovered within one second.
 
If that's a PSU problem it's mighty subtle.

 
It should not have dipped *at all*
 

Well, ten millivolts isn't much and nothing's perfect.
 

Have you got a storage scope you can put on it?
>

Yes, but it's an Owon USB 'scope so a bit of a circus to hook
up. When I get the present crop of alligators fed I'll give it
a try. For now wired networking is good enough.
 

My guess - without massive confidence - is that there is a momentary
brownout of a lot less than 5.06V.

A very reasonable suspicion.

And, a good call.

Found a spare usb-c power supply and tried it. 5.45 volts on the GPIO
pins. That seems kinda high, but the Pi5 seems happy with it. It does
grumble something about usb_max_current_limits during the boot output
but doesn't put the info in dmesg, so it's hard to act on it. Something
about messing with config.txt, but after all the trouble of the past
few days I'm just glad it boots.

Still having trouble getting dual monitors working, but that's a subject
for a new thread.

Thanks very much for writing!

bob prohaska