[sdiy] Retaining button state after power off?

Ullrich Peter Peter.Ullrich at kapsch.net
Fri Jan 31 23:14:59 CET 2014

Hallo Justin!

Have a look at these articles:


same appnote can alse be found in EDN:



Von: synth-diy-bounces at dropmix.xs4all.nl [synth-diy-bounces at dropmix.xs4all.nl]" im Auftrag von "Justin Owen [juzowen at gmail.com]
Gesendet: Freitag, 31. Jänner 2014 17:51
An: SDIY List
Betreff: [sdiy] Retaining button state after power off?


I have a couple of simple analog circuits that allow you to cycle through 2, 3 or 4 options/outputs/etc using a momentary push switch.

So, for a 2-cycle switch, click 1 is 1, click 2 is 2, click 3 returns back to 1 and so on. For a 4-cycle it's 1,2,3,4,1,2,3,etc.

The circuits output either a high or low state

The problem is that these circuits return to their default state on power off.

What would be the simplest way to write the button state to some sort of non-volatile storage that could be reinstated at start-up?

I'm guessing a micro is going to be the most likely answer - but if there is a non-programming option available it would be great to hear. Failing that - absolute simplest solutions where possible please!


- J

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