Re: WP34s low battery shut down? Message #7 Posted by Harald on 2 Mar 2012, 3:30 p.m., in response to message #6 by Marcus von Cube, Germany
Quote:
Your shutdown idea will not work because the battery backed RAM in the processor will fail if you disconnect power.
I think you didn't quite get what I was trying to say (unless I am going wrong somewhere here). Disconnecting the battery is ONLY supposed to happen if the calculator is left unattended with a flat battery and not rechard for a long period of time. This is to protect the battery under those circumstances.
That is also precisely why under normal circumstances I would like the calculator to shut down BEFORE the battery gets to the level where it needs to be disconnected. Thus preventing memory loss, as the battery stays connected.
Quote:
If you plan to let the calculator sit on the shelf for any longer period of time, just do an ON+STO which will create a copy of the RAM in flash. You can then remove power without any loss (except for the built-in RTC).
Yes, so that is what I would do if I wanted to leave the calculator for a longer period of time without recharging it. Because in that case the battery might disconnect itsef.
I hope this time my idea was presented in a slightly more understandable way. :)
Cheers,
Harald
PS: I think I figured out how to do this. Next I will need to build and test the circuit and find a way to integrate this into the calculator. I am thinking the space above the display (under the HP logo) is suitable. I'll keep you updated.
Edited: 2 Mar 2012, 3:33 p.m.
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