JP1 Remotes

Only this one is the reverse of what I would have thought.

Fresh batteries cause the parallel interface to fail, but the ones I've been using for a week make the interface work fine. I originally repalced them to see if the remote had better range/angle of transmission; testing the best case scenario. They run the unit just fine, but interface is a bust with them in. Each new AAA cell is a fresh energizer alkaline AAA pulled from a freshly opened pack and test at aruound 1.80v each. The older RadioShack alkaline batteries are testing at around 1.59v each. Tried 4 different cells from the same new energizer pack, and the parallel interface does not function. It could be a drain or overvoltage issue.

Anyone seen this behavior before? Any thoughts? It had me checking for a broken wire in the interface before I just tried the old batteries as a wth. Was not expecting that to work. I'm going to have pull and save the magic RadioShack ones to make sure that I can continue using the interface. I guess I could try to drain a set of the energizers to see if that works

Thanks in advance.

Yup, this is a well known peculiarity of the JP1 interface. Unlike most devices that you might hook up to your PC, the Simple JP1 interface gets it's power from the parallel port, which isn't a very reliable source of power. If the batteries in your remote are brand new, they might be giving the remote too much voltage, which would be a problem if the voltage from the parallel port is not high enough.

This is why one of the tricks that we ask people to try is to reverse one of the batteries in the remote. In fact, why don't you try this with your fresh batteries. In other words, with the fresh batteries in the remote, watch the interface fail, then reverse one of them and watch it work. It's weird, but hey, who's arguing if it works, right?

A reversed battery makes the interface work with the new batteries. The display is dim on the reset, but the remote does talk, uploads, and resets properly.

Thanks for the quick response!

It's a known issue; different remotes and different computers behave differently for different battery combinations varying from no batteries thru reversing one battery (half voltage) to rechargeable NiMHs (1.2V-ish each) to brand new alkaline cells. Most people who encounter the problem come up with a combination to suit their particular setup. One suggestion for an adaptable solution would be to use, say, 4x1.5V cells and a 10K pot and 10K fixed resistor to give 0 to 6V:
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UQ - great idea, but where would you fit the pot and all that stuff from your hi-res graphics here ?

I use ultra cable because 3.5v laptop was just too much hassle with the battery issue when I used standard batteries. BUT, recently I used the simple cable on another 3.5v laptop AND my 8910 has 1.2v NiMh batteries and I had no problems. A miracle. Those batteries seem to last forever, well worth the 3x or 4x price of the standard ones.

mkmcgregor wrote:Only this one is the reverse of what I would have thought.

Fresh batteries cause the parallel interface to fail, but the ones I've been using for a week make the interface work fine. I originally repalced them to see if the remote had better range/angle of transmission; testing the best case scenario. They run the unit just fine, but interface is a bust with them in. Each new AAA cell is a fresh energizer alkaline AAA pulled from a freshly opened pack and test at aruound 1.80v each. The older RadioShack alkaline batteries are testing at around 1.59v each. Tried 4 different cells from the same new energizer pack, and the parallel interface does not function. It could be a drain or overvoltage issue.

Anyone seen this behavior before? Any thoughts? It had me checking for a broken wire in the interface before I just tried the old batteries as a wth. Was not expecting that to work. I'm going to have pull and save the magic RadioShack ones to make sure that I can continue using the interface. I guess I could try to drain a set of the energizers to see if that works

Thanks in advance.

I guess you failed to read EVERY sticky post in the entire forum, or else you would have stumbled upon THIS

Yes, I did stumble upon it, of course this was after I posted it and got a most excellent reply explaining the situation about voltage supply through the parallel port. The sticky was under the subject of parallel cable problems, and I was having a communication problem based on batteries. So I guess that I glossed over it. I should have done a more intensive search.

I will pay more attention to those sticky notes, since they appear to be the stock solutions for common problems!

Thanks for the heads up.