Troubleshooting GPIs and GPOs

Troubleshooting from the command line

Q: I just picked up a MeasurementComputing PCI-DIO24 card and am having trouble getting it setup. I notice that in RDadmin when I define the new device in "Switchers GPIO" as Local GPIO as layed out in the GPIO.txt, the default device path is /dev/gpio0. The problem is that /dev/gpio0 doesn't exist.

A: The PCI-DI024 cards aren't supported in recent Linux Kernels, so it may not work for you. If you have an old kernel: Sounds like you don't have the GPIO driver turned on. You can get that from the Rivendell download page. Install it, enable the 'gpio' service and you should then have a '/dev/gpio<n>' device node to correspond to each MC card in your system, along with entries in '/proc/driver/gpio/' to show you the status of each.

You can check these by opening a terminal and running the following to check if the gpio devices have been created:

ls /dev/gpio*

This will return something like this:

gpio0

To check the status of the device run the following in a terminal:

ls /proc/driver/gpio/*

This will return something like this:

card0

You can then run the following to see the status of card0:

cat /proc/driver/gpio/card0

Troubleshooting with GUI utility program RDGpiMon

See the wiki page about RDGpiMon for information about it.

Other useful Wiki pages

GPIO.txt_-_GPIO_Notes_for_Rivendell