Hi There,
I'm pretty new to the Arduino world but have alot of experience with Industrial control systems.
I am current in the process of designing a PCB/Product and have come across a possible issue.
The product will be used in cars and therefore is required to be powered on but in a low power state when the car is turned off to prevent parasitic drain on the battery.
Currently the plan to do this is to route to car's switched "Accessory" voltage (12V) into the PCB, it will then be run through a signal converter to 5v and finally to the interrupt pin D2 on the Nano (With a Pull-down to ground). The grounds of these circuits are linked.
On the software side I plan to save the current state of some variables to EEPROM and then enter a deep sleep state when the car's ACC goes LOW. Conversely, when the car's ACC goes HIGH or is RISING I want the Arduino to wake up.
Now here is the rub. I have been reading a lot of forum posts on doing a similar thing. However there is some conflicting information around.
Is it possible to wake the Arduino from sleep with a RISING signal on the interrupt pin? or is this impossible and only able to be done with a FALLING or LOW signal necessitating the use of a inverter.
Additionally would utilizing pin change also complete this task?
Thanks!