Page 1 of 1

gpio internal pull up

Posted: Wed Feb 14, 2024 6:05 pm
by hansommen
Hello,
Is there a way to activate the internal pull up resistors for gpio on the raspberry (original image) version
if i check /sys/class/gpio/gpio17 the file active_low has 0 in it so the input should be up.....
Thanks

Re: gpio internal pull up

Posted: Thu Feb 15, 2024 8:56 am
by GGGss
Did you define the direction of the GPIO port? in / out?

Code: Select all

echo out > /sys/class/gpio/gpio18/direction

Re: gpio internal pull up

Posted: Thu Feb 15, 2024 5:13 pm
by hansommen
thanks for your suggestion, it gives No such file or directory but on gpio17 there is nothing responced
in qlc i can configure pin 17 as input so i did that, for this time i placed 10k resistor as pull-up so my show is running. I made this show in a compiled version of qlc + wiring-pi but the startup time was too long and i decided to use the original image file (€15) and there is no access to gpio in terminal

Re: gpio internal pull up

Posted: Thu Feb 15, 2024 11:51 pm
by mcallegari
https://raspberry-projects.com/pi/comma ... mmand-line

This is what QLC+ does on the Raspberry Pi

Re: gpio internal pull up

Posted: Sat Feb 17, 2024 10:31 am
by hansommen
Thanks, i'll test it, for now the external pull-up is working fine and with your image file the the start up time is short, perfect!!

Re: gpio internal pull up

Posted: Mon Feb 19, 2024 9:45 am
by GGGss
Just keep in mind that QLC+ reacts on a rising edge signal on the GPIO. So you need 2 edges to switch from a zero to a one and back to zero. (Or you use a Schmidt trigger circuitry.)