"No remote found" with homemade JP1.2 cable

[WagonMaster]

From the above, it sounds like if I manually pulled pin 4 to ground, and then momentarily connected pin 2 to ground, I should not see any LED blinks. However, if I perform this procedure, I do see two blinks and the remote is normally operational.

I just tried this on my RS 15-135 remote. When I simply let JP1 pin #4 float (high) and cycle JP1 pin #2 by grounding/releasing it, I see the 2 LED "reset" flashes. When I ground pin #4 first as you did and cycle pin #2 the same way, I do not get the 2 LED flashes. And pressing buttons on the remote does not light the LED, so I can probably assume that it's correctly gone into serial comm mode.

Does that mean that pin 4 is not correctly connected inside the remote? Realize that with the RS 15-100 I had to add a ribbon cable to the PCB in order to access the JP1 pins.

Yes, it's very likely that your RS 15-100 mod may have a flaw. I'm glad you reminded me about this. It actually crossed my mind and then I foolishly forgot about it while addressing the other stuff.

By the way, after I posted last night, I tried that 'comtest.exe' app I referred you to under Linux+Wine. The first few times I ran it, it came up, but the expected pop-up dialog to set the COM port settings was nowhere to be found, so it appeared as if the app was locked up. On a later run, it worked as expected at first, but then the pop-up dialog wouldn't disappear, making it effectively locked up again. I also ran it under Windows and confirmed that you can easily use the 'Ctrl-R' hotkey to toggle the 'RTS' setting on then off and you will see 2 LED flashes if your interface (and RS 15-100 mod) are working correctly. You can do that over and over and you should see 2 flashes each time.

Bill

[srwalter]

Indeed there was a connection issue inside the remote for pin 4. After repairing that, I can now manually put the remote into serial comms mode and also reset it to normal. In fact, once I have manually put the remote into serial comm mode, I can use a MAX232 TTL-RS232 driver to talk to the remote; IR now successfully uploads and downloads from the remote.

However, the JP1.2 circuit still has trouble. I also noticed that the IR led gets hot when connected to the JP1.2; so hot in fact that I blew up the transmitter and had to replace it with a radioshack part. wtf?!

[srwalter]

So I think the problem was that I'm only getting like 1v between pin 1 and pin 3 of the remote. Rather than chase that down, I'm going to use an external power supply (which is effectively what I had with my MAX232 circuit).