Look at the datasheet of the ATtiny45. In the section “Sleep Modes”,
there is a table that lists the wake-up sources available for each sleep
mode. For the mode “power-down”, INT0 is listed as a possible wake-up
source, but there is a small footnote:
For INT0, only level interrupt.
This means that the CHANGE mode you are trying to use will not wake-up
ATTINY's are designed to easily do this since they can wake from power down sleep mode by a pin change...
Basically you want to...
Connect a normally-open push button between an IO pin and ground.
Enable the pull-up on the IO.
Enable the pin change interrupt on the IO pin.
Enter "power down" sleep mode.
When the button is pushed, it ...
Two of those 10mA come from the ATECC608 crypto chip which idles at 2mA. That leaves 8mA for you to track down.
The WiFi-NINA module has multiple "sleep" modes that range from 30mA down to 4.5µA. Since you can't be in the 30mA "modem sleep" mode (it's too high for your measurements) I suspect it enables "light sleep" at 800µA.
The switching regulator ...
standard current you can draw from a usb port is 500 mili ampere with 5 volt(you may get even more but it is not recommended) . so if you want to calculate
sensors are very low current about 1~2 mA(but you must check out datasheet)
turbidity for example draws 30 mA
temperature ds1820 is 1 mA
flow is up 2 mA
the LEDs based on resistors series with them ...