[How-To] Monitor a device using a status light

[chrishallowell]

I got the prototype working perfectly. Thanks Frank for all of your help.

Thanks,
Chris

 

[FrankMc]

Hi Chris

>I got the prototype working perfectly. Thanks Frank for all of your help.

Good stuff .....;-)....

Frank

 

[dtreyes]

My replacement washer and dryer now have the status light indicator, as opposed to the old rotary which I monitored easily using the magnetic sensor. To monitor my new washer and dryer using its status light, I tried electron's photocell idea and attached them to Elk M1 input but with no success. Does anybody know if I have to change the value of the resistor to get this to work. Thanks

 

[BraveSirRobbin]

What do you have the zone type as? Note in electron's article he stated the difference between "on" and "off" was:

the measurements were 4.12 VDC and 2.12 VDC

What voltages are you getting? You may have to set the Elk zone up as an Analog type and write rules to see if it is say above 3.5 volts or below 2.5 volts.

 

[dtreyes]

What do you have the zone type as? Note in electron's article he stated the difference between "on" and "off" was:

the measurements were 4.12 VDC and 2.12 VDC

What voltages are you getting? You may have to set the Elk zone up as an Analog type and write rules to see if it is say above 3.5 volts or below 2.5 volts.

I am getting 7.5 and 9.2. I am trying to connect it to M1xin but since I need analog, I might have to move it to the main board. I will give it a try. Thanks

 

[IVB]

Thanks for this writeup, i'm looking to use it and a photoresistor to see if the SageHDExtender is on or off. I put the photoresistor on, and put in a 5.6K resistor (t was what I had), but I only get a seperation of 9.6V (on) to 9.8V (off). Same spread as without a resistor.

Would getting a much beefier resistor (10K, 100K) help at all?

 

[mustangcoupe]

I would expect some type of change with a diffrent resistor... But you should also make sure you are not seeeing any ambient light in the room and this is not triggering it. (if you are unsure, turn off the light. If you have alot of natural light, try putting it in a enclosed dark container)

 

[electron]

You will need to use electrical tape to isolate the light, but in this case, I think you would be better off with a CR magnetics current sensor. It will look much nicer (invisible). You could probably even scrape the SageTV web interface to see if it is on, and report that status to your M1/CQC setup.

 

[IVB]

Thanks guys, I'll answer the photoresistors questions here and leave the Elk thread to just "how to create analog rules".

I can predictably see different voltages between LED on & off, it's just that it's very very small. (9.6V vs 9.8V).

Which polarity did you plug your wire from LED light (via photoresistor) to input zone? If you have your wire plugged into positive polarity, perhaps you need to hook up the wire to negative.

Forgive me, i'm new to photoresistors. I got the RatShack ones which have 2 wires coming off and look symmetrical, so I just ran both wires into the Elk zone. Are you saying to flip them?

You will need to use electrical tape to isolate the light

Yep, did that.

I think you would be better off with a CR magnetics current sensor

Not following;the HDExtender is always "on", just in standby mode. Not sure if it draws significantly less current in standby, is that what you're talking about?

 

[electron]

You are probably right, forgot about the 'standby' mode. What about using CQC to scrape the status of the extender? I am planning on doing this myself so I can automatically trigger events based on the status of the extenders. Anyways, that would be for a different topic. Good luck.

 

[IVB]

The sticky wicket is that the device is non-responsive via TCP in standby mode. The SageWeb interface doesn't even show the extender if it's in standby mode. Stupid, really, I think.

 

[electron]

Mine still accepts telnet connections/pings, even when 'turned off', so it should work.

 

[IVB]

But how do you know if it's in standby or not? That's what i'm looking to do, so if someone presses the "sage" button on my MX850, it turns on the TV, turns on the Denon, switches inputs to SageTV input, and optionally sends the power-toggle button to the HDExtender.

If there was a discrete power on for the Extender, this would all also be moot.

 

[IVB]

So it would seem that the HDExtender's green light isn't bright enough to truly trigger the photoresistor. With just that, blacked out with electrical tape, I get 75K Ohms of resistance. With no LED on, I get infinite/open circuit.

But...with ambient light, I get 2.5KOhms. That would be a nice seperation between 2.5K Ohms and open, but that's not what I got.

I'm contemplating drilling out the faceplate in front of the Extender if front of the green LED to see if that helps the cause. perhaps the glass is tempering it too much.

 

[IVB]

Schawing!!

I had to completely disassemble the HDExtender to get the front plastic plate off, but after drilling it out I now get 8.8V if LED is on, 13.4V if LED is off!

Now off to see if I can figure out how to make that damn analog rule work...