SparkFun Forums

[sdisselhorst]

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.

[busonerd]

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

[trialex]

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.

[sdisselhorst]

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?