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Re: What is the quintessential Apple II?



Roger Johnstone wrote:
In <6d2dnRllDOiodzjYnZ2dnUVZ_t-mnZ2d@comcast.com> Alex Freed wrote:

"mdj" <mdj.mdj@gmail.com> wrote in message 1168492727.215181.185180@p59g2000hsd.googlegroups.com">news:1168492727.215181.185180@p59g2000hsd.googlegroups.com...

But then to me, using a uC to make lights flash is ugly. It can be done simpler ways, and I prefer reaching for caps and resistors to swap on the breadboard than pulling a uC, going back to the PC and
reprogramming it. If I want to change the flash rate, I'll build
variability into my design.

I did not *seriously* suggest using microcontrollers to blink LEDs -
just pushing the point to the extreme and beyond.


I love using microcontrollers to blink LEDs. Admittedly I've never added a micro to do just that, but if there's a pin available there's nothing better than using it to pulse-width modulate a LED so that it turns on and off softly.

Great example--and fun!

I did however use an 8 pin uC for a battery charger in one design
and I'm very happy with the result.


A customer recently brought in a faulty timer board they wanted replicated. All it had to do was switch on a load once every 24 hours for a short time which was adjustable. The board looked overly complicated so I traced out the circuit to see exactly what it was doing. The original designer had used an 8-pin micro for the 24 hour timer, and a 555 timer IC with a variable resistor for the adjustable time. The best of both worlds!

We made a new board with a single 8-pin micro on it which performed both functions. The resistor for the variable time is read by the micro charging up a capacitor, then timing how long it takes to discharge it through the resistor. I'm surprised no-one thought of doing that before ;
o)

Yes, that's a favorite trick for cheap analog input.

-michael

NadaNet networking for Apple II computers!
Home page:  http://members.aol.com/MJMahon/

"The wastebasket is our most important design
tool--and it's seriously underused."