Accelerometer - WKP Interrupt only works when USB connected?

I use the following library:

But instead of connecting INT1 to D2, I connect it to WKP and enter Deep Sleep. When the device is connected by USB cable, it wakes up fine. When it is powered only by the battery however, it will not wake up anymore. I tested it with several devices and several protoboards, and none of them work.

Any thoughts?

Fixed this; the things I found (could be of use to other newbies?):

  • ADXL362 should be hooked up to 3V3 in this case; with VIN collecting data works fine but INT will not work anymore
  • After entering Sleep mode, it requires about 10 seconds before it can wake up again