UIRT1 with external IR-Receiver ?

[Holger]

Hi,

I know thet for the UIRT2 it is already done. But is there any Problem for UIRT1 to put the IR-Reciever not directly on the PCB but connect it via shielded cable to the PCB?

Best Regards
Holger

[Robin]

No, there's no problem ... but why didn't you just try it anyway ?! :D

[vbray]

I would add that some measures will help cut down on interference...

1. Use the beefiest shielded cable for this. I reworked mine using good quality s-video (in a former life) cable and that helped alot.

2. As suggested in response to my post here http://www.girder.nl/phpBB2/viewtopic.php?t=2083 the L-C filter works wonders. I still get some interference, but much improved. You can scrounge the 'L' off just about any fried circuit board (modem, motherboard, etc.) and get the cap at radio shack. Look on the circuit board for the little surface mount thingys with an 'L' printed on the board next to them.

Vince

[Marsupial]

Er... how/where do we build/implant the LC filter?

Also, is there any fancy calculations to the values of the L and the C or we literally take any capacitor/bobine combo?

Since I'm close to start building my uirt2 (just need the pcb and some extra time - all other parts are in now) I'm checking on those to make sure less trouble are getting in while I'll test this...

[Holger]

Yesterday I finished my work and it works fine. Sometimes there are some detections of codes without having pressed a button, but this is no problem because I do not think that there can be a code generated accidently which matches to one programmed. Nevertheless I will do what Ruud recommend in a mail and solder a capacitor at the end of the cable.

Best regards
Holger

[Robin]

Marsupial ... Yes there are fancy calculations if you want to do them, but as you don't actually know what it is you're trying to filter anything has to be better than nothing (plus it means I don't actually have to do any real thinking, which is always a bonus). This filter is for cleaning interference from the power rail, so you're creating a very low pass filter (how low is not known).

Holger ... Although these accidental code detections don't seem like a problem at the moment I'm pretty sure it'll annoy you later. I hadn't realised that every time my UIRT receives an IR signal (whether it's intended for the UIRT or not) Girder attempts to process the data ...

This isn't normally a problem, however, when I'm watching a DVD the mouse pointer is usually hidden. This Girder activity un-hides the mouse pointer, which can be annoying. Your erroneous data will probably do the same thing (unless you move the mouse off-screen as I do now).

[vynce]

Here is an L-C filter calculator that you can use to design them: http://www-users.cs.york.ac.uk/~fisher/lcfilter/.

[Marsupial]

Ok, so I can rip off any inductance from an old (anything) and put it with a 100n capacitor for a nice LC filter?