| 623 | | === Double edge trigger |
| 624 | | |
| 625 | | OcteonTX GPIO's support double edge trigger, this will create an IRQ on both the leading and falling edge of a signal. |
| 626 | | |
| 627 | | Here is an example using a GW6304. |
| 628 | | |
| 629 | | Create an input GPIO and "high" GPIO, these are CPU-DIO's: |
| 630 | | |
| 631 | | Connect Push button normally open (push-to-make switch) between leads attached to J13 pin 1 and 2. |
| 632 | | |
| 633 | | {{{#!bash |
| 634 | | #Create double edge input GPIO |
| 635 | | echo 488 > /sys/class/gpio/export |
| 636 | | echo in > /sys/class/gpio/gpio488/direction |
| 637 | | echo both > /sys/class/gpio/gpio488/edge |
| 638 | | #Create "high" GPIO |
| 639 | | echo 489 > /sys/class/gpio/export |
| 640 | | echo out > /sys/class/gpio/gpio489/direction |
| 641 | | echo 1 > /sys/class/gpio/gpio489/value |
| 642 | | }}} |
| 643 | | Watch IRQ events: |
| 644 | | {{{#!bash |
| 645 | | watch -n 0.5 cat /proc/interrupts |
| 646 | | }}} |
| 647 | | Look for "GPIO 24 Edge" IRQ count increase on both edges of signal. |
| 648 | | |
| 649 | | Note that early revision Newport boards did not have on-board pull-ups on the off-board DIO's thus they would need to be provided off-board - see [wiki:newport/DigitalIO] for details |
