First, this Boston stuff is interesting. I actually used to live in New Hampshire (Merrimack, then Amherst), but moved away at the end of 1993. I spent 10 years bummin' around the Boston area. Kathi (then my girlfriend, now my wife) couldn't stand the snow, black flies, mosquetoes, etc, and made it pretty clear that if we didn't move, she would. Since Kathi was pretty important to me, I viewed that as an important safety tip on how to keep Kathi hangin' out with me! [Linked Image from softronix.com]

Anyway, back to the subject of this thread:

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However, in some cases this doesn't work very well such as with a cable box that doesn't have a switched outlet - often the current draw difference between standby and off is so small that a current sensor won't work. For other discrete commands, there is often no workaround that will work.

With discrete IR commands, you don't need additional logic to keep track of state (which gets broken if the user uses the original remote or uses front panel controls).

I totally disagree with this! First, yes, some devices don't work well (such as a cable box), but that's why you use a video sync sensor. That works perfectly on a box that draws minimal power when on vs. off. I have a LOT of gear, and I have yet to not be able to sense power.

Second, even when I do have discrete power controls, I still do power sensing? Why?

  • Many devices (Meridian 861, most Sony TVs, my Yamaha receiver, etc) doesn't accept commands for a brief period of time after powerup. Thus, if I know that the unit was off, I know that I need to wait a bit before sending further commands. Sure, I can always wait (in case it was off), but I prefer my system to be as fast as possible. By sensing power, I can optimize how quickly things happen.
  • Some devices may behave slightly differently on power up. For example, depending on configuration, the Sony G90 may go into a "warm-up" mode (all white screen). If I know that I just powered on the projector, I can query to see if we're in warm-up mode and cancel it (depending on how the system was powered up).
  • You say things get "broken if the user uses the original remote or uses front panel controls". And that's exactly WHY you'd do power sense! No matter what the user does (front panel, original remote - which we don't have out anyway, those are all put away - no need to use them with the Panja automation system), with power sense, we can make sure that the system is in a reasonable state.
  • By doing power sense, I can be optimal in my use of RS-232 commands and I/R blasts. For example, why send an ON command when I don't need it, and why wait 2 seconds in case the device wasn't on? Instead, if I know the TV is on, for example, I can just send the command I need. When I want to turn my gear off, why send 10 commands out when one or two would suffice?


Sure, I have discrete power commands for my Sony TVs, and for my Sony G90, and for a bunch of other gear. Sometimes I even use them (although it generally doesn't matter). But, in all cases, I still have found useful purposes for power sense - stuff that I absolutely needed power sense in order to do.

As far as I'm concerned, discrete commands (at least for power) are critical if you have a "dumb" remote (i.e. a Pronto, for example, that has no state). But if you have an intelligent, computer controlled system, discrete on/off is a big yawner.

Other discrete commands (i.e. discrete video commands) might be nice for the Sony TVs, but it generally takes, at most, 2 or 3 I/R blasts to get those to operate in a discrete fashion, so that hasn't been all that important. And, other than the Sony TVs (which can trivially be worked around), everything else I have already has discrete I/R for everything I need.

Just my opinion, anyway, based on a fairly well-tuned home automation program.

[This message has been edited by Jeff Coffler (edited 05-08-2001).]

861, 800, G68, Sony G90, Snell&Wilcox Interpolat