Very stupid Newbie

humpda · Post by **humpda** » Sat Sep 16, 2006 5:40 am

Hi
I finally bought myself a JP1 remote - 8910(Bo2). I made myself a JP1 cable (simple parrallel cable) , and am having problems getting anything happening at all. When I connect the remote and run IR (V5.05) I get a message stating "No response from the remote - make sure the JP1 interface is plugged in properly. During this message, I get a whole lot of weird characters on the remote LCD....but nbothing else. It tells me the port is functioning correctly but nothing much else to my untrained eye. Question - have I stuffed up my cable or is there something else I have done? I had a quick look through the dummies guides but I must be a bigger dummy cos most errors seemed to occur after you have successfully connected and I can't get that far

johnsfine · Post by **johnsfine** » Sat Sep 16, 2006 6:15 am

I think the weird characters you describe are what the 8910 displays for a moment when it does a hardware reset.

The JP1 interface includes a signal that can cause a hardware reset.

The JP1 software tries to trigger that reset at the end of any operation, whether success or failure.

So most likely, the reset wire and the ground wire in the cable are right and one of the other wires (SDA or SCL) is wrong. SDA is the one with the diode, so it has the most ways it might be wrong.

But it may be possible to get the same symptom with the cable plugged in wrong, so that SDA or SCL is connected to the reset line and triggers the reset operation. (I expect one of the hardware experts would have a better guess of whether that is really possible).

humpda · Post by **humpda** » Sat Sep 16, 2006 6:35 am

Hi
Thanks for the prompt reply

....Is there a place I can upload a picture of my crappy soldering job so that someone can tell me where I have stuffed up? Not 100% sure by what is meant by SDA or SCL - I soldered two wires to the resistors on pins 3/4 and soldered diode to pins 2 and 11. Where could I have stuffed up? Thanks heaps once again

johnsfine · Post by **johnsfine** » Sat Sep 16, 2006 7:12 am

humpda wrote:Not 100% sure by what is meant by SDA or SCL

Notice the "Theory of Operation" section of SimpleRev5.doc
It shows the Schematic of the JP1 cable in context with a partial schematic of the remote.

Pin 5 of the 6 pin header is RESET. Your symptoms seem to indicate that signal is doing something reasonable during attempted use.

Pins 4 and 6 of the six pin header are SDA and SCL. Your symptoms imply one of those has a problem.

For example, SDA takes a connection from pin 4 of the 6 pin header to pin 11 of the DB25, plus a diode from that connected point to pin 2. I think IR.exe gives a different error message if the diode were missing or backwards (I'm not certain). But connecting both the wire and the diode at pin 11 may be trickier soldering (beyond my ability anyway) so maybe that wire isn't properly connected.

Do you have an Ohm meter to check connections?

My digital camera, even in macro mode, couldn't take a picture good enough to spot a soldering problem. But if your camera can, posting such a picture in the diagnosis area (and URL back here) is a good idea.