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Arne
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Joined: 05/01/2025
Location: Germany
Posts: 46

Posted: 10:48am 18 Jan 2026

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Is there an easy possibility to block the output of data to the GPIOs before/during setting of GPIOs as outputs. My code is as follows:

SetPin 24,dout
SetPin 25,dout
SetPin 26,dout
SetPin 27,dout
SetPin 29,dout
SetPin 31,dout
SetPin 32,dout
SetPin 34,dout
SetPin 11,dout
SetPin 12,dout
SetPin 14,dout
SetPin 15,dout
SetPin 16,dout
SetPin 17,dout
SetPin 19,dout
SetPin 20,dout
Port(11,2,14,4,19,2,24,4,29,1,31,2,34,1)=&B1111111111111111

If I start the program for approx. 5ms (during the SetPin - phase) unintended outputs to the GPIOs happen. A flickering of < 1 ms would be ok.

Any ideas ?

Arne

matherp
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Joined: 11/12/2012
Location: United Kingdom
Posts: 10868

Posted: 11:06am 18 Jan 2026

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The pins will be high-Z when the program starts. If important you would need pullup or pulldown resistors on your board

phil99

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Joined: 11/02/2018
Location: Australia
Posts: 2940

Posted: 11:23am 18 Jan 2026

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> pin(1)=1 :setpin 1,dout :? pin(1):pin(2)=1 :setpin 2,dout :? pin(2)
1
1
>

So you could try:-

Pin(24)=1 : SetPin 24,dout
Pin(25)=1 : SetPin 25,dout
Pin(26)=1 : SetPin 26,dout
Pin(27)=1 : SetPin 27,dout
Pin(29)=1 : SetPin 29,dout
Pin(31)=1 : SetPin 31,dout
Pin(32)=1 : SetPin 32,dout
Pin(34)=1 : SetPin 34,dout
Pin(11)=1 : SetPin 11,dout
Pin(12)=1 : SetPin 12,dout
Pin(14)=1 : SetPin 14,dout
Pin(15)=1 : SetPin 15,dout
Pin(16)=1 : SetPin 16,dout
Pin(17)=1 : SetPin 17,dout
Pin(19)=1 : SetPin 19,dout
Pin(20)=1 : SetPin 20,dout
Port(11,2,14,4,19,2,24,4,29,1,31,2,34,1)=&B1111111111111111

It should make them go straight from high-Z to 1 without first being set to 0 (the default after Setpin) before the port command.
Edited 2026-01-18 21:33 by phil99

Arne
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Joined: 05/01/2025
Location: Germany
Posts: 46

Posted: 12:22pm 18 Jan 2026

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To set the pins before SetPin command worked perfect.

Thanks all,

Arne

DaveJacko
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Joined: 25/07/2019
Location: United Kingdom
Posts: 92

Posted: 09:26pm 18 Jan 2026

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While we're on the subject of GPIO..
can anyone point out what stupid mistake I'm making here?

wire together GP0 and GP1

setpin GP0,dout
setpin GP1,din
pin (GP0)=1
print pin(GP1) - prints a 0 !!

also tried pin(GP0)=0, and PWM 1Khz 50%
checked with a meter, volts/freq as expected.
Just getting 0 on GP1
(I'm ultimately trying to get a settick type interrupt > 1 KHz )
Thanks in anticipation mates.

Try swapping 2 and 3 over

phil99

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Location: Australia
Posts: 2940

Posted: 10:24pm 18 Jan 2026

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> setpin GP0,dout : setpin GP1,din
> pin(GP0)=1 : ? pin(GP1)
1
>

Check with a meter that you are getting 3.3V on GP1 at the pad on the Pico module.
If so you may have a dead pin. Try GP2 etc.

DaveJacko
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Joined: 25/07/2019
Location: United Kingdom
Posts: 92

Posted: 10:54pm 18 Jan 2026

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Thanks, Phil, I've tried that bit of code verbatim right now..
mine returns a zero
yes, I previously checked with meter, 3+ volts
tried another pico zero, same.
I think I may be making an even more fundamentally stupid mistake,
I'll sleep on it with a glass of Aussie red,
will let you know how I get on

Try swapping 2 and 3 over

JohnS
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Joined: 18/11/2011
Location: United Kingdom
Posts: 4209

Posted: 11:12pm 18 Jan 2026

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DaveJacko said While we're on the subject of GPIO..
can anyone point out what stupid mistake I'm making here?

wire together GP0 and GP1

setpin GP0,dout
setpin GP1,din
pin (GP0)=1
print pin(GP1) - prints a 0 !!

also tried pin(GP0)=0, and PWM 1Khz 50%
checked with a meter, volts/freq as expected.
Just getting 0 on GP1
(I'm ultimately trying to get a settick type interrupt > 1 KHz )
Thanks in anticipation mates.

You have a space after pin in
pin (GP0)=1

Please try it without the space (sorry, I'm guessing it matters here but may be wrong).

John

DaveJacko
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Joined: 25/07/2019
Location: United Kingdom
Posts: 92

Posted: 11:25pm 18 Jan 2026

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thanks, John, but well spotted!
tried it, don't think that's the problem.. sleeping on it

Try swapping 2 and 3 over

phil99

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Joined: 11/02/2018
Location: Australia
Posts: 2940

Posted: 11:31pm 18 Jan 2026

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I would have expected that to be the issue too, had I noticed it. A CODE window makes spaces clearer.
However :-

> pin(GP0)=0 : ? pin(GP1)
0
> pin (GP0)=1 : ? pin(GP1) '1 space
1
> pin (GP0)=0 : ? pin(GP1) '1 space
0
> pin (GP0)=1 : ? pin(GP1) '2 spaces
1
>

Did not expect that!

TassyJim

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Joined: 07/08/2011
Location: Australia
Posts: 6433

Posted: 11:52pm 18 Jan 2026

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It should work as presented.
As Phil suggested, try GP2 etc
To see if one of the pins is reserved for some system purpose, try

new
option list
list pins

Jim

VK7JH
MMedit

mozzie
Senior Member

Joined: 15/06/2020
Location: Australia
Posts: 196

Posted: 02:12am 19 Jan 2026

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G'day DaveJacko,
It might be a good idea to post the version of PicoMite and options list you are using, it could be a problem with a specific variant or option rather than generic.

I have tried your code on a RP2350A and RP2040 using V6.02.00RC7 and both work as expected, something strange going on somewhere.

What happens if you apply 3v3 direct to GP1?

Regards,
Lyle

EDIT: Also tested on RP2040-Zero with V6.02.00RC7 and it works as expected. Possibly an option setting conflict?
Edited 2026-01-19 12:45 by mozzie

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