JP1 Remotes

Ellen

I have an old JP1.2 interface cable that I made from one of Tommy's excellent construction guides entitled BUILDING A JP1.x INTERFACE from August 2006. Those instructions provided for building either a JP1.x interface that would work with both JP1.1 and JP1.2 remotes or, with the removal of some of the components, a JP1.2-only interface. I think those instructions are obsolete now as I don't see them in the Files section.

Can the JP1.2 interface described in that old doc be used with JP1.3 remotes? I ask because I read a post from Rob that said that the wrong interface will kill a JP1.3 remote.

If I need to build a new interface for JP1.3 remotes from the newer schematic in the files section, I'll do it. But I'd rather not if I don't have to since the new docs are schematics only and don't include the construction details that made the DIY interfaces easy for noobs. I can solder, but I have trouble laying out components without a road map.

The Robman · Posted: Fri Aug 07, 2009 6:28 pm Post subject:

The important thing when using a JP1.2 interface with a JP1.3 remote is to not have pin #5 connected.

If you cut wire #5 as close as possible to the IDC you should be OK.

This pic shows where I usually cut it:

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Rob
www.hifi-remote.com
Please don't PM me with remote questions, post them in the forums so all the experts can help!

WagonMaster · Joined: 16 Apr 2009 Posts: 361

Ellen · Posted: Fri Aug 07, 2009 7:08 pm Post subject:

Thanks for the info guys.

I should have thought to upload the doc. Here it is.

WagonMaster · Joined: 16 Apr 2009 Posts: 361

Thanks, Ellen... that upload helps a lot. I took a look at the hardware interface design in that document and it's the exact same hardware design as the one that's currently documented (by the inimitable Tommy Tyler, of course) as a JP1.1-only interface. (Technically, that interface will work with all 3 JP1.x remote types, but not with the software that's out there.)

If you built it as JP1.2-only (with just 3 transistors), you should be in good shape to use that interface with your JP1.3 remote(s) because there will be no transistor "Q1" driving pin #5 at the remote control end.

As stated in other threads, however, you still should be sure that you don't have a wire emanating from the JP1.x remote's pin #5 since it can act as an antenna and cause problems. That means that you should cut the wire to pin #5 where Rob described.

If you built it as JP1.1 + JP1.2 (with all 4 transistors), then cutting wire #5 takes care of the problem!

So, in summary: Carefully do what Rob suggested. Smile

Bill

The Robman · Posted: Fri Aug 07, 2009 11:13 pm Post subject:

If you have a steady hand, use a blade (not too sharp) to separate wire 5 from the rest of the wires on both sides, then if you have some small nail scissors, use those to cut the wire. Or, if you can something under the wire, raise it up a bit and then cut it with a blade.
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Rob
www.hifi-remote.com
Please don't PM me with remote questions, post them in the forums so all the experts can help!

Ellen · Posted: Sat Aug 08, 2009 4:05 am Post subject:

Gentlemen,

Thanks for taking a look at that doc.

Hopefully the minor surgery you suggest won't be too difficult. I gave up on ribbon cables, and in the more recent interfaces I have built I have used braided individual wires:

I think this will make cutting the one to pin 5 easier to do than separating a ribbon cable.

I appreciate your help. Thanks much!

The Robman · Posted: Sat Aug 08, 2009 11:37 am Post subject:

It should be easier as you won't have to first separate the cable from the rest of the ribbon. However, if it proves to be harder than you thought, you might want to temporarily remove the strain relief.
_________________
Rob
www.hifi-remote.com
Please don't PM me with remote questions, post them in the forums so all the experts can help!