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From: Ahem A Rivet's Shot <steveo@eircom.net>
Newsgroups: comp.sys.raspberry-pi
Subject: Re: Need help with PI PICO...
Date: Sun, 24 Mar 2024 07:23:46 +0000
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On Sat, 23 Mar 2024 22:20:34 +0000
The Natural Philosopher <tnp@invalid.invalid> wrote:

> On 23/03/2024 18:37, Ahem A Rivet's Shot wrote:

> > 	Assuming you have access to the source of gpio_get() instrument
> > the inside of it with tracers (I'd use printf if there's anything
> > listening to stdout - otherwise find somewhere to put breadcrumbs that
> > you can see in real time (in ancient times I'd just watch the
> > blinkenlights). Wait for it to lock up and see what it's doing.
> > 
> Well I did. That's how I got this far.

	Instrument /Inside/ gpio_get().

> I know it enters the routine, but never leaves, and the lack of GPIO 
> voltage suggest it is being stuck where it is.

	Right so the next step is the inside of the routine.

> > 	Alternatively run it under strace or similar and wait for it to
> > lock up or wait for it to lock up and attach gdb (you'll want to compile
> > with -g for that).
> > 
> AIUI those are linux tools.

	Unix tools but yes.

> We are running bare metal-ish here.

	Ah - no way to attach a debugger via the SDK ?

> Back in the day I would have used a chip emulator with hardware break 
> points.

	An ICE is always nice if someone else is paying :)

> It's odd, it may be something to do with short ultrasonic distances.  I 
> have the PCB just lolling around on the desk, and facing a wall a few 
> inches away seemed to make it crash moire predictably

	Hmm is there a minimum range spec ?

-- 
Steve O'Hara-Smith
Odds and Ends at http://www.sohara.org/
For forms of government let fools contest
Whate're is best administered is best - Alexander Pope