[34S] occasional RTC reset upon power on

[MarkHaysHarris777]

(03-22-2015 03:00 AM)John Galt Wrote:  The WP 34S is obviously very fast, even in SLOW mode. I wish there were a way to slow it down even more, to get more life out of the batteries or to provide more warning to the user that they're about to die. Perhaps CR2032 cells just weren't designed for the load it demands.

I just wish there were a better way of utilizing the low battery indicator... which is the subject of that other thread.

hi John, ... that's why I pointed you to the link with the small code snippet. Tuck that snippet away someplace in the back of your WP34s (whatever I mean by that) and run it from time to time... set the counter to something meaningful... it should load the cpu briefly, but not run so long that IT kills the batteries!

When the batteries are getting weak the battery indicator will flicker a bit 'while' the nop loop is running, but before the batts are dead.

That's about all you can do. We might snoop through the code a bit (there may be more than just 'slow' and 'fast' on the Arm; Marcus would know the details. Maybe there's a way to cut the clock one more time?

As a side note: This is not for everyone (I'm not recommending this to anybody) but I am going to be modifying my WP34s with a docking station; IMHO its the best way to print, program, transfer peer-to-peer &c, and still have power. If all you need to do is peer-to-peer transfers then the micro stereo phone plug is the best way to go. But if you need the whole kit'n'kabootle then a docking station is the best way. Essentially, its a small box (cardboard works great) that runs a ribbon cable (six lines) into the back of the WP34s (with the back cover off, and the batteries removed) while the calculator sits on top. The cable plugs in via six pin header (completely concealed with the back cover on). The docking station has the IR diode(s), power pack (3v), transfer TxRx, and FTDI chip if desired. In my opinion NONE of that crap should be mounted in the 34s itself (there is not enough room, and the coin cells are not adequate for the job).

I do a lot of programming (constant looping) with my unit. My coin cells don't last long in that environment. They are fine for routine calculations, and some programming cycles; but not long running jobs... they just can't handle it.

Cheers,
marcus