I need to handle a 3.3V interrupt signal coming from an external sensor. Is it possible to use a GPIO of the EC to do this? If no, are there other solutions?
So how is this question related to your other one here? https://www.udoo.org/forum/threads/eapi_test-and-gpio.32189/
Strictly speaking, it is not related. I have to use some GPIO's as outputs and one GPIO as input. So, the other question is fundamental to determine the logical ID's associated with the physical pins available on connector CN25. Regarding the input signal, I would like to avoid polling it to detect when it changes. Of course, this is feasible, but extremely inefficient. I would waste a lot of CPU time. That's why I'd like to use an asynchronous mechanism instead.
I am not familiar with EAPI so I suspect you already checked that EAPI cannot handle interrupts. If you can convert the 3V signal to a keyboard signal (eg someone pressed letter A) you perhaps can use the standard keyboard scanner function. The build in Arduino Leonardo can handle interrupts but if you need the PC part to act on this interrupt you will have to poll the serial port. If the Arduino itself can act on it this will be the best solution and independent of the CPU load.
I did. Unfortunately, it seems there is no interrupt support I thought about it, but it seems keyboard matrix is not supported either I found this thread regarding this topic https://www.udoo.org/forum/threads/11x5-keyboard-matrix-support.26759 Nobody answered ... I would not discard this option, if the overall latency of the chain (signal changing state -> Arduino Leonardo -> USB -> Linux application) is acceptable. By the way, can you link an sketch example for UDOO Bolt's Arduino Leonardo?
For interrupt examples check Arduino documentation https://www.arduino.cc/reference/en/language/functions/external-interrupts/attachinterrupt/ For communication see https://www.udoo.org/docs-x86II/Serial_Libraries/index.html or use Arduino Firmata (protocol based on MIDI) https://github.com/firmata/arduino
