Cable Length

[Luc]

You could try it with the cable between PCB and PC but not between PCB and receiver, there will probably be too much disturbances.

I would not recommend to use a cable that long between PC and UIRT, it can work but will it be reliable? The best solution would be to convert the UIRT signals to proper RS232 using a MAX232 or equivalent.

[Luc]

The UIRT supplies the comm port with levels of 0 and +5V.
The standard RS232 uses -12V and +12V.
This doesn't create problems because for almost all RS232 ports a low is everything below +2V and everything above this is considered as high.

The MAX232 only converts the UIRT levels to RS232 levels using a single 5V supply and does nothing with the data.

There was somebody else mentioning this in the forum, maybe he can help you out as he might have succeeded. Otherwise I could try to make a drawing but it involves 2 IC's and other components, not THAT simple..

[windtrader]

Vynce,

I am using a UIRT2B (internal) with a 25 ft shielded 24 gauge six conductor cable for the the emitter and receiver signals. One end uses the supplied plugs and jacks that connect to the PCB, the other end has the two emitters attached to one pair of the cable and the receiver, cap, and ferrite core soldered to three other wires.

The cable runs from the HTPC down the back of an equipment rack jammed with all kinds of low and high power cables, under the floor into another room, up the wall into a bookcase where I mounted the emitters and receiver.

So far, things are working fine. On the commands I have fully configured, the signal seems quite reliable. Also, after I "tuned up" the orientation of the emitters and receiver, the signal improved.

I am using the recommended ferrite and cap mod. It made a HUGE difference for me. Look at the external connections/connecting the IR receiver section of the web guide. Go to the following forum topic for the link.

http://www.girder.nl/phpBB2/viewtopic.php?t=2189

Don

[windtrader]

vynce,

Glad it worked! How long a Cat5 cable did you end up running between the PCB and receiver? What does the cable travel by along its length that could cause noise or interference?

Are you using the IR Debug function in the UIRT2 plugin? I thought there was a function that listed out the codes not just the bar?

FYI - My unit running shielded cable is operating perfectly. I did add another set of emitters using 20 ft. of cat5 and emitters with a different spec than the original. I was a bit concerned that it might not work but it seems to work at least at short range. The spec states 2.1V @ 50mA 940nm T1 - 3/4 (5mm). They are clear, not blue.

Don

[krbuck]

I just want to be sure I understand what I'm doing before I start desoldering/soldering my brand new UIRT2A's IR receiver.

I want to mount the receiving component about 25 feet (about 7.5 meters) from my HTPC. All my emitters will be mounted near the PCB, so they don't need to be remote to the PCB. The only thing I need moved is the receiver.

How does this sound?

1. Carefully desolder the IR receiver from the board, leaving the LC circuit intact on the PCB.
2. Solder three leads of a cat5 pigtail cable directly to the PCB and mount the PCB using some suitable strain relief.
3. Connect the 7.5 meter cat5 cable to the short length via a connector and run it out to where I want to mount the receiver.
4. Mount the reciever, solder the appropriate leads to the cable using a strain relief.
5. Test.

Will this work?

Many thanks! --Karl

[vynce]

I have a ~7m unshielded CAT5 cable between the UIRT2 PCB and the receiver/transmitters and it has worked perfectly for the last few months. I haven't had any problems due to interference. The only difference that I see between what you're planning to do and what I have done is that I have the LC filter at the receiver end of the cable.

UIRT2B-------Long Cable-------LC--Receiver
in PC                        \____Transmitters

There are two 3.5mm stereo audio plugs on each end of the cable. One end of the cable plugs into the UIRT2B the other end plugs into a box that houses the receiver and transmitter. I think I had each data line twisted with a ground - so data from the receiver was twisted with ground from the receiver, etc. Using a shielded cable would work even better (or even a fiber optic cable :lol: ).

[krbuck]

vynce,

Many thanks for the response. This is exactly the confirmation of my approach I needed.

Now I just have a serial, component and svideo cable to figure out, and I'll be all set. =)

Cheers. --Karl

[izone]

"1. Carefully desolder the IR receiver from the board, leaving the LC circuit intact on the PCB. "

The L-C filter should be as close to the IR Rx module as possible.