19 Apr
2012
19 Apr
'12
12:01 p.m.
The 555 is starting to be not very visible in
industry, either. There are
very few applications these days that are so simple - there always seems to
be some sort of microprocessor hanging around that can be in some ways
utilized - with the advantage of not needing the 555s resistors and
capacitors and all the issues they bring.
Like reliabbiltiy and repairability ;-). A metal-film resistor, used
below its ratings, will outlive any microcotnroller. And as I've said
before, I don;t ahve the problems with capacitors that some seem to.
Commerically, you want to sell new devices, That means making the old
ones hard to repair, or at least hard to repair without buying expensive
spares from you. Microcontrollers are ideal for this, you can protect the
code so that a repairer either has to buy one from you (or more likely
buy the complete PCB ;-(), or spend many hours writing his own version of
the code. If its a 555 and a few R's and C's, then anyone can fix it (if
it ever fials, which is less likely ...)
OK, soemwhat tongue-in-cheek, but only somewhat...
It's also worth rememerbign that what is sensible for a production run is
not necessarily sensible for a on-off hobbyist design. In the former case
it's worth spending longer designing it (e.g. by taking the time to
program a micorcontrollr fro the job, thus reducing the thign to one IC
and a few other compoennts), since it will simplify production. In the
latter case it can be worth using more components if it simplifies the
design or debugging stages.
Ultimately it's up to the designer. If you consider the options and
decide a microocnrolelr is what you want ot use, then fine. Go and do it.
What makes me cringe are people who come out with 'Oh, just use an
Arduino' without considerign other options, in fact without thinking
abotu the problem at all.
-tony