The AVR chip already has pin change interrupts which give a similar functionality
But I'm not sure how such interrupts are configured via the Arduino IDE and libraries.
Say 7 and 4 come in at the same time so you get an interrupt and handle 7. Then 7 goes away leaving 4 on the pins. BUT an OR gate will not change state so you don't get the second interrupt.
IO expanders like the MCP23017 will do this, 16 potential interrupts with latching.
Please enter a valid email to subscribe
We need to confirm your email address.
To complete the subscription, please click the link in the
email we just sent you.
Thank you for subscribing!
via Egeo 16