GPIO 8 Starts True?


4 posts
by kghunt » Thu Jul 12, 2012 7:38 am
I have a buzzer attached to GPIO 8 (pin 24) and everytime I reboot my Pi it goes off like mad until I set it to false manually?

Is this just the nature of that pi and its secondary function? Should I swap the buzzer to one of the primary GPIO's or can I make it stop.
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by gordon@drogon.net » Thu Jul 12, 2012 9:21 am
kghunt wrote:I have a buzzer attached to GPIO 8 (pin 24) and everytime I reboot my Pi it goes off like mad until I set it to false manually?

Is this just the nature of that pi and its secondary function? Should I swap the buzzer to one of the primary GPIO's or can I make it stop.


Is this recent kernel? If-so, then I think it's the SPI driver - it seems to set a couple of pins to be active outputs and sets them high.

So what I did was to make sure those modules were not loaded at boot-time - if this is the issue, then create /etc/modprobe.d/gpio-blacklist.conf and put in it:

Code: Select all
blacklist spi_bcm2708
blacklist i2c_bcm2708
blacklist w1-gpio


and reboot.

To see if it is the cause, try typing lsmod and looking for those modules.

-Gordon
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by kghunt » Thu Jul 12, 2012 10:38 am
awesome thanks got rid of that annoying buzzing sound every time I reboot :-).
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by gordon@drogon.net » Thu Jul 12, 2012 10:59 am
kghunt wrote:awesome thanks got rid of that annoying buzzing sound every time I reboot :-).


Great!

You can always use the modprobe command to re-load those modules later if you have a project that uses SPI or I2C.

-Gordon
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