Using Two Arduino to Lower Power Consumption I am planning to build a water quality sensor with ph, temperature, and dissolved oxygen, conductivity. The power consumption looks like it will be very high especially due to the signal isolator, I'm estimating about 250mA. I'm going to place it in a remote area so I need it to be as power-efficient as possible.
I was thinking would this work?
What if I use two Arduino to control the power? The first Arduino will control the power supply to second Arduino, which has the sensor installed, using a timer(RTC) to turn off the power for 30 minutes and on for 30 seconds for it to read the sensor data.
Can this work? What would the circuit look like?
For the isolator, I was thinking to use Tentacle Shield and in the documentation, it says that the isolator itself uses about 150mA plus the sensor circuit.
https://www.whiteboxes.ch/docs/tentacle/t1/#/
Thanks for the help.
I would do as follows:
Software:

Arduino is in sleep mode

every x seconds (x depending on your needs), wake up then switch on and read one sensor after the other and transmit the results or whatever you want to do.

then go back to sleep


Hardware:

as you have 4 sensors, you can connect their outputs to the arduino analog inputs (or digital...)
you will need 4 electronic switches, preferably Mosfets, connected to 4 digital outputs to switch the power of each sensor independently

This should reduce the consumption to the minimum.
Once your system is running, you may also think about using only the AVR microchip, not the complete Arduino, e.g. If you don't need the USB connection. In addition, you can further reduce consumption by clocking the AVR chip to a lower clock, if not using Arduino.