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Re: What is the quintessential Apple II?
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.
> 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)
--
* Roger Johnstone, Invercargill, New Zealand -> http://roger.geek.nz
* PS/2 Mouse Adapter for vintage Apple II or Mac
* SCART RGB video cable for Apple IIGS