Noise Problems?

[ccarpenter1]

I am receiving what looks to be noise on one of my bus controllers. I have three modules. One USB which is located upstairs and two serial bus units that are located downstairs. The USB module has an external opiwer supply and it powers the other two bus modules through a 3-wire configuration. It seems to happen at random times, but the module downstairs flashes its green light intermittently. Here is a sample of what I receive when it happens.

Any ideas on what the problem might be?

Thanks!

22:21:42 : S00
22:21:42 : S0
22:21:44 : S0
22:21:45 : S0
22:21:46 : S0
22:21:52 : S031245
22:21:55 : SS
22:21:56 : S00
22:22:05 : SS
22:22:07 : S0
22:22:08 : S00
22:22:09 : S0
22:22:09 : S0
22:22:15 : S0
22:22:17 : SS
22:22:18 : S00

[YoYo]

Very interesting....

The only thing I can think of off-hand is interference from CFL fixtures??

I do know that compact fluorescents do emit "noise" in the IR band used for most remote controls. When I had my Xantech setup, I had to order some "CFL friendly" receivers to get anything to work in one of my rooms.

When I went to the IRTrans, I had to replace some of the CFLs in just that room with regular bulbs. I talked to the IRTrans folks about this recently, and they said all of the newer IRTrans devices ship with "CFL friendly" receivers in them so this is no longer an issue.

If I send my older units back to them, they offered to "upgrade" my older units with the "CFL Friendly" receivers as well for a small charge. I haven't gotten around to it yet, but am planning to do so at some point...

Maybe you could try turning off any light sources in the room to see if that's where the interference is coming from...

Is the interference keeping things from working properly?

[ccarpenter1]

Found Source of Noise Problem

Hey Brian,

I found the source of the noise problem. I really don't understand why it is happening, so I thought I would get your opinion on it. Here is my setup. The IRTrans Bus Unit in my bedroom (20x15ft) is sitting on top of my HTPC case. Above the HTPC case is a wall mounted Sony 46" LCD HDTV. So, the IRtrans is almost (about 1 foot in front) directly underneath the TV. The IRTrans is facing a lot of mirrors on the opposite wall.

Here is what I have noticed. When the TV is on and there is no active source currently set to the TV and only the current Input text is displayed on the TV, this is the time that I see the flashing green lights indicating the noise. The IRTrans "sees" the text from the TV of the current input reflected off of the mirrors on the opposite wall.

Turn the TV off and the noise goes away. The IRTrans is running the 3 wire configuration, so the power to the unit is coming from the USB unit upstairs, so the TV and the bus unit are on completely different circuit breakers.

Any ideas?

Thanks!

[Rupp]

That's a very common noise problem when dealing with IR. LCD's and CFL's are the 2 worse IR "flooders" known. Did you try moving the mirror (assuming it can be moved)?

[YoYo]

Hmmm, that's very interesting. I knew that plasma TV's put out IR interference, but I never knew that about LCD's. (I'm still using a rear projection TV for my HT, but I have declared that '08 will be the year of Hi-Def at our house!)

ccarpenter1,
Is it actually causing a problem with the operation of the system?

I'm afraid I'm not going to be much help to you on this, maybe somebody else would want to jump in here...

Have you tried contacting the IRTrans people?

[ccarpenter1]

IRTrans Noise Problem

Hey Brian,

Sorry, I haven't got back with you sooner. The only problem it is causing is when I try to learn new IRs, it makes it very difficult to "avoid" the noise problem since it is being sent to the other units. I guess I could temporarily disable the revceiver part until I am through learning the new commands.

I talked to Marcus at IRTrans and they confirmed this is a problem with some LCDs TV as well. They have offered to send me an updated one once I send them the original unit.

[YoYo]

Ah yes, I'm sure it would affect learning. When you say disable the receiver, do you mean turn off the LCD TV? If it's causing the interference, I guess you could turn it off while you're learning commands..