[geeks] microcontroller stuff

[Fogg, James]

> How about if you want to control things (detect circuit open/close &
> switch relays) via a serial port but don't want to touch a soldering
> iron? ie: standalone interface box. Anything reasonably priced out
> there?
> 
> Someone just invited me to do all the eletronics for an art gallery
> installation at some really high-profile (NY?) gallery, but I don't
> know anything about electronics, and I don't have the gear to control
> via computer.


What you might want is PLC's. Programmable Logic Controllers. These devices
use *any* of a huge variety of input modules (temp, motion, light, contact
closure, contact opening, TTL pulse, mass air sensor, water sensor, etc.).
The PLC then allows you to program the outputs desired by the input or combo
of inputs. The output modules are, again, of a huge variety. High voltage
contacts, high current contacts, valves, etc. You can sequence, chain,
check, etc. for conditions.

The programming uses simple ladder logic for most functions. I had to help a
friend learn the PLC "language" and I had never seen it before. It made
sense to me after the first page. Very simple for computer geeks to
understand.

PLC's are standardized (mostly) and made by several manufacturers
(Allen-Bradley was one I knew). Electrical and industrial supply houses have
them. These things can be used to control hugely complex manufacturing
systems and are very versatile. The cost is reasonable and probably less
than the time/material needed to futz around with interfacing
microcontrollers to what you want for output.