I have an arduino mini with an ultrasonic sensor conected to the pins 2 and 3, and a RGB LED connected to the 4,5, and 6, I want to include a wake up and sleep functionality that wakes up when receive a high signal in another pin as 7.

I have seen that normaly the pins for that are 2 and 3, as in the arduino web: Arduino sleep web

But can it be done with another pin?

2 Answers 2


As well as the normal external interrupts INT0 and INT1 you can also wake the chip through a variety of other interrupts. One of those is the pin change interrupt.

In the datasheet is a table of what is available in the different sleep modes, and what can wake you from that sleep mode. I have compressed the table to remove a lot of the stuff you don't care about at the moment and just show the "wake-up sources":

enter image description here

As you can see both INT and PCINT can wake from all modes (along with TWI [Wire.h] slave mode address matching).

The note (3) on the table just says that for INT0 and INT1 it must be a LOW level interrupt, not a RISING or FALLING. No mention is made of the type of interrupt for PCINT.

So yes, since pin 7 has PCINT facilities (all pins on the ATMega328P have PCINT) you can configure that as a wake-up source and wake the MCU using pin 7.


Arduino Mini has only two interrupt capable pins: 2 and 3. You have to move your sensor to other pin.

From the AtMega328p datasheet:

If a level triggered interrupt is used for wake-up from Power-down, the required level must be held long enough for the MCU to complete the wake-up to trigger the level interrupt. If the level disappears before the end of the Start-up Time, the MCU will still wake up, but no interrupt will be generated. The start-up time is defined by the SUT and CKSEL Fuses.

  • You forgot PCINT...
    – Majenko
    Oct 25, 2017 at 10:18
  • @Majenko. You are right. Your answer is better. What do i do?
    – user31481
    Oct 25, 2017 at 10:26
  • There's not a lot you can do besides plagiarise ;) It's up to the OP to do whatever he fancies.
    – Majenko
    Oct 25, 2017 at 10:55

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