I'm working on that cool project that is power efficient .
I'm working on a project that auto power the arduino at a given time and keep it on for less than a minute then it should switch off automatically too .
I'm using an external circiut for sending a signal for the switching on purpose ( DS3231 board )
http://www.play-zone.ch/en/combo-breakout-mit-ds3231-temperatur-zeit-24c32-memory.html
So I am trying to build up a circiut that when it receives a signal from the DS3231 board it latches the signal for a while to autopower the arduino board then it switch off again saving much much battery power .
I built up that one but still struggling to make it work.I am worried that it will waste more power than it saves due to the 100 ohm resisters.Would anyone have a proper circuit ?
i/p is where I connected to the SQW pin of the DS3231 board and +5v is connected to Vin pin in the arduino and GND to the GND pin as well in the arduino board
any help ??
Best Answer
It is probably easier and more efficient to just have the processor on the Arduino sleep when idle rather than building a whole other circuit to disconnect power. The AVR chip on the Arduino is amazingly low power when sleeping, possibly drawing less power than the circuit you are going to build to turn it on and off.
You could connect the output of your sensor to an input pin of the Arduino to have trigger the wake up.
Note that if you are using a standard Arduino board that you will need to make some changes to get minimum power usage during sleep (primarily disabling the voltage regulator). You will want to do this anyway if you will be running off a battery since the regulator is very inefficient.
Try googing "low power sleep arduino" and "arduino wake sleep" for more specific instructions.