USB-UIRT Forum

I just received a SmartHome IR emitter and plugged it into my USB-UIRT. It doesn't appear to be working, i.e. when I change channels and point the USB-UIRT at my cable box it works fine but when I use the emitter I don't see any lights flashing on it.

I think maybe its a dud. Is there an easy way to check this? Or is there some other setup I need to perform, aside from plugging it in? Do I need newer firmware?

Frustrating if its bad, shipping was twice the cost of the actual unit.

Thanks,

-- M

Some things you can check:

1. To check and make sure the 1/8" jack on the back of the USB-UIRT is working: Plug a set of stereo headphones into the USB-UIRT and transmit an IR signal. You will hear it on the headphones. Make sure the audio is present on BOTH the Left and Right channels.

2. Some plugi-in emitters are not visible, so you'll only be able to test them with the device you're trying to control. Most are *very* low power, so they must be placed *directly* over the IR receiver on the equipment you're controlling.

-Jon

I can definitely hear it on the headphones. It sounds like an old pulse telephone dialing.

I ruined my SmartHome emitter in the process of trying to debug it. I bought an IR emitter from Radio Shack and soldered it to a mono mini plug/cable. I used a multimeter to verify my soldered connections. Its not working either.

I'm at a loss here. I've got the IR LED right up against the receiver on my cable box. It changes just fine when I point the USB-UIRT at the receiver, but the IR LED doesn't appear to function at all.

Here are the specs on the Radio Shack emitter:

Electrical characteristcs (25 degrees C)
Radiant power output (100mA): 16 mW min.
Forward voltage: 1.2V
Forward current: 100mA
Viewing angle to 1/2 intensity: 45 degrees

Absolute maximum ratings (25 degrees C)
Forward voltage (20mA): 1.6V
Reverse voltage: 5V
Forward current: 1.2A
Reverse current: 10 uA
Wavelength: 940nm

The cable box is a Motorola DCT 6200. I'm operating under the assumption that the IR receiver is just to the right of the channel indicator.

Have you verified proper polarity on the emitter?

You need to ensure: ANODE is connected to the connector TIP.
CATHODE is connected to connector BARRELL.

-Jon

jrhees wrote:Some things you can check:

1.... Plug a set of stereo headphones into the USB-UIRT and transmit an IR signal. You will hear it on the headphones...

2. Some plugi-in emitters are not visible, so you'll only be able to test them with the device you're trying to control. ...

-Jon

Re:1, one might note that it is not necessary to actually put the phones in/on your ear, as the sound is plenty loud (as I found the hard way )

Re:2, if you get sound but still not the control of device you expect, you can extend your diagnosis by visually confirming a working (or non-working) IR emitter using many models of digital camera or camcorder, as they are actually sensitive into the near IR - just turn on the cam, point the lens at the emitter, and watch in the viewfinder. I tried four cams and 3 of the 4 showed the IR flashing in their viewfinder, even though (of course) this is not visible to the naked eye when looking directly at the emitter (the fourth was a newer Sony camcorder, and when I turned on Nightshot mode it worked too, making 4 for 4). More hints: try it with the built-in emitter(s) first to verify your cam works; and with some cam/plugin emitter combinations, you need to get the cam pretty close to the emitter to see it flash, the plug ins are not nearly as bright as the builtins and this may be further reduced because there may be some degree of filtering built into the cam hw or sw.

FWIW,

-tom-