I want to use it for a soap dispensing application so I do want it always on or ready to go on once a hand is there. I've got 4 Simple human soap dispensers at home and all of them have died or aren't working except 1. Their two year warranty has expired.
They also drain 4x AAA alkaline batteries within ~6 months.
So I decided to try to make my own.
I didn't even consider what you mentioned.
Here is the link to the sensor:
Oh man .
Well that's going to defeat the purpose of the power savings.
I think the lowest the datasheet says it can do is 12.5 mA based on certain test conditions.
I found this it looks impressive regarding deep sleep or sleep mode.
Only problem is Arduino compatibility.
Wish Arduino was using some native hardware that doesn't need any modifications that can operate at really low power in sleep mode without modifications. I've seen some posts online i.e. arduino pro mini with no led, arduino uno atmel chip on breadboard, etc... Microchip Technology Extreme Low Power (XLP) microcontrollers
I wonder if there are any lower power proximity sensors out there. PIR sensor, .1 mA static current
I found this but I generally find that PIR sensors are a bit too sensitive. I had a soap dispenser in the past that had a really bad sensor. It would dispense every time a bathroom light was closed. The Simple Human dispensers have a sensor similar to the APDS-9960.
Here is the device for reference: https://grabcad.com/library/automatic-soap-dispenser-parts-1