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Topic: Vin and arduino sleeping? (Read 465 times) previous topic - next topic

madepablo

Sep 07, 2010, 09:02 pm Last Edit: Sep 07, 2010, 09:03 pm by madepablo Reason: 1
I am involve in a project that will measure different environmental parameters through different sensors once per hour. The other time it will be sleeping.

However, i would like to have a led blinking in order to know that it still have enough power and it is alive. I plan to use something like this:
http://www.kpsec.freeuk.com/projects/dummy.htm

This explanation is to ask you if i could go over the input voltage from by batteries by connected the circuit of the example to the Vin pin or arduino when it is sleeping? and ground pin?

Thanks!

deSilva

To really profit from sleep modes you have to use a different board. The voltage regulator, the power LED and the FTDI chip will use too much current.

The Vin will go through the voltage regulator, so you need something above 6 volts (which will also contribute to dissipation)..
But you can inject 5 volts directly into the 5 volts pin.

3x1,5 volts batteries will do fine for that purpose..

fdufnews

#2
Sep 07, 2010, 10:05 pm Last Edit: Sep 07, 2010, 10:06 pm by fdufnews Reason: 1
If you use the led blinking circuit it will show you that there is power but not that the arduino is still alive.
To know if the arduino is alive you should blink the led with the arduino itself.
To do that you can put the atMega in sleep mode and program a timer to wake it up blink the led and return to sleep. If the ratio of the time it is alive versus the time it is sleeping is really short the consumption will be negligible.

Udo Klein

And the canonical example of how to sleep and wake up for short periods seems to be this:
http://interface.khm.de/index.php/lab/experiments/sleep_watchdog_battery/

Udo
Check out my experiments http://blog.blinkenlight.net

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