[avr-chat] AVR on 1 AA bat with just 1 L and 1 C

[hanzl]

Sorry but I just have to share my perverse idea with you.

I think e.g. ATtiny15 could be operated from just one 1.5V battery
using just one coil and one capacitor and mis-using the AVR chip to
act as a switched power supply for itself. Look:

                    ....................
         coil       :       AVR        :
    -------uuuuu----:port           vcc:----
   |                :pin    gnd        :    |
  ---               :..................:   --- cap
   =  bat                    |             ---
   |                         |              |
    -------------------------+--------------

Strange, is not it? Yes, battery goes to port pin only. Yes, on vcc,
there's just the cap and nothing else. But wait, I think it could
work:

1) AVR grounds 'port pin', current flows via coil

2) AVR leaves 'port pin' floating, current still flows via coil and
now it charges the cap via internal over-voltage protective diode on
the pin

Did I miss something?

Well, how to switch it on... Maybe a pushbutton between port pin and
gnd :-) ?  Not a big offense in a perverted design like this one...

Bye

Vaclav

P.S. Sorry for being off-topic maybe even on avr-chat but there is
nobody around who would listen to me just now ;-) (Disclaimer: I try
to do sane designs most of the time, however just now it is not the
case. ;-) )