Battery backup for memory in Arduino Duemilanove

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Battery backup for memory in Arduino Duemilanove

Postby sdisselhorst » Wed May 12, 2010 3:45 pm

Is there an easy way to save the memory of the Arduino using a battery backup of some kind? I want to avoid my counters zeroing out from brief power loss. I am powering them with +5v from a regulated power supply tied right to the +5v points on the prototyping board. I also have +12v from the power supply available. I haven't been able to find a good solution anywhere on the web.
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Re: Battery backup for memory in Arduino Duemilanove

Postby busonerd » Wed May 12, 2010 5:39 pm

Power supply -> schottky diode -> +5V
Coin cell - >schottky diode -> +5V

Make sure you don't try to run anything but the AVR off the onboard +5V, or your coin cell won't last very long.

--David Carne
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Re: Battery backup for memory in Arduino Duemilanove

Postby trialex » Wed May 12, 2010 6:52 pm

Depending on how you are using these variables - i.e. how often they update, you could store them in EEPROM - it is not cleared when power is removed. There is 512 bytes available, and a library to show you how to do it.
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Re: Battery backup for memory in Arduino Duemilanove

Postby sdisselhorst » Thu May 13, 2010 5:57 am

I am running a 20x4 lcd screen off of the same 5v. Isn't there some way to just put power right to the chip for memory backup?
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