I've copy and pasted a post of mine out of Nabble with minor changes.
Time to ask it again again :-).

While this allows for unusual but available solutions, knowing what
prices people are finding for the entry level in various more common
devices would be a good start. eg Marechiare suggested that PIC10Fxx
should be available at around 10 cents in volume. That would be nice
but seems unlikely - what is the lowest known real-world price for the
10F etc? .

Philips LPC may be good candidates. Obviously PIC and AVR. TO maybe.
Other ... . I could troll the various manufacturers sites again again,
and probably yet will, but knowing what people already know would be
good.

Two categories are probably of interest .
- Lowest cost come what may subject to development and availability
issues as below.
- Lowest cost with 2+ ADC.

_______________________________

May 2009, RMc on Nabble escrit ...

" ... Must be time for standard question number 16.3.4(a) again :-).

What is the cheapest sensibly accessible and usable microcontroler around?
That needs qualifying.

- Aim is ability to do at least "what if" investigations on a modest budget,
even if final development work was done 'elsewhere' ie must not
necessarily need custom hardware or software costing thousands of
dollars.

- Ideally will operate from say 2V - 5.5V (so otherwise rather nice looking
5V only ST7FOXxxx a non starter)

- Starts and stays running well in real world (ie good POR and
anti-brownout. Maybe watchdog).

- Operates or able to operate on internal oscillator.

- Has some I/O ( :-) ). (2 just maybe, 4 better, 6 good, more nice)

- Timer a welcome bonus (few wouldn't have)

- Interrupts(s) a welcome bonus (most have)

- ADC a most welcome bonus

- Comparator a bonus.

- PWM a bonus.

- Non utterly arcane instruction set a bonus (eg (long defunct) F8
need not apply ;-) ).

- Flash versions for development or even windowed eprom OK  - if production
parts are OTP. Mask for production if it must be. Die & COB in due course if
it got the cost down.

- Available in modest volumes (ie you can buy development quantities.

- Modest cost development tools available (ie assembler available, can be
programmed easily enough or basic programmer available).

The PIC 10F2xx is about as good as I can find so far.
10F200 not much over $US0.30 in thousands before you start haggling.
4 I/O. Timer. Comparator.

PIC16F54 is not much dearer. Timer. No comparator. Substantially more I/O.

Holtek may yet do far better.
I'm just starting to dance the dance of finding out.

There is a world (I'm told) of arcane 4 bit creations 'out there' - but
generally development access is not easy.

Other suggestions most welcome.

Under $US0.30 in thousands to 10,000 to ... possible OK.
25 cents getting good.

Anything that can achieve $US0.20 in 100,000+ would be very nice

At that price with say 6 I/O I could probably even tolerate no timer, no
interrupts, no ... .

And, odds are, almost anything will have these.

Thoughts?
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