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All leds blinking

Posted: Tue Sep 24, 2013 1:10 pm
by geirmash
Hi! I just got my gertboard and i am trying out some examples.
The example i am testing out is the one from Gordon projects.

code is as follows:

Code: Select all

#include <stdio.h>
#include <wiringPi.h>

// LED Pin - wiringPi pin 0 is BCM_GPIO 17.

#define LED     0

int main (void)
  printf ("Raspberry Pi - Gertboard Blink\n") ;

  wiringPiSetup () ;

  pinMode (LED, OUTPUT) ;

  for (;;)
    digitalWrite (LED, 1) ;     // On
    delay (500) ;               // mS
    digitalWrite (LED, 0) ;     // Off
    delay (500) ;
  return 0 ;
When i run it, ALL the leds blink, and not only one.
I have wired up GPI17 to B1 as described.
I have the preassembled gertboard.

Is something going wrong here or am i just doing something wrong? :?

Re: All leds blinking

Posted: Wed Sep 25, 2013 9:01 am
by itsmedoofer

I found exactly the same thing when I tried the example..

My first mistake was I didnt read the instructions for setting up the board properly, I didnt set the power jumper or the jumpers for output, there are pics around for this if you are unsure....

Secondly when I did all this they all still lit up, however I believe this is down to the design of the board, apparently the buffers have high impedance that makes them a bit flaky unless pulled down some how...

Better explanation here:- ... -wiringpi/

Does say later boards shouldn't see this, I got mine beginning of September and had the issue...

Hope this helps a bit....

Re: All leds blinking

Posted: Thu Sep 26, 2013 1:35 pm
by alexeames
Have you put the Gertboard "On top of" the Pi or "next to" the Pi?

Re: All leds blinking

Posted: Thu Sep 26, 2013 11:05 pm
by itsmedoofer

Mine sits on top at the moment, was thinking of getting a ribbon so I can go side by side though this seems more practical. Could it be interference from the Pi causing this then ?

Should have a bread board and lots of link wires coming tomorrow so can have a proper play. :P


Re: All leds blinking

Posted: Fri Sep 27, 2013 8:20 pm
by alexeames
itsmedoofer wrote:Hiya,

Mine sits on top at the moment
do you mean like this?
Image because that is the right way round.

Re: All leds blinking

Posted: Sat Sep 28, 2013 7:13 am
by itsmedoofer

Yea got them setup like that, phew :)

Re: All leds blinking

Posted: Thu Dec 12, 2013 10:48 pm
by ytram99
I also say the problem of all the LEDs blinking and was rather dismayed.

Please see my two blog entries:

This one discusses the problem: ... -leds.html

This one discusses what I did about the problem (soldered resistors to the Gertboard).: ... board.html: