JP1 Remotes

Hi all,

I just bought this interface board with the intent of making a new JP1.X interface to replace my old 3-transistor one: Amazon FTDI board

Unfortunately, even though it resets the remote (1056B01 Atlas OCAP), I get "Remote not found" from RMIR or JP1XTest.exe. I have checked the wiring multiple times and I have confirmed pins 1 and 5 are not connected, 2 is RTS, 3 is ground, 4 is TXD and 6 is RXD. The interface has power, RXD and TXD LEDs, and I can see that when I try to test or download from the remote, the TXD LED is flashing but not the RXD LED.

I decided to try the troubleshooting technique in this document: Instructions for using the Realterm program to identify a flash remote
I believe this has given me some good information. After I do the basic Realterm setup and connect a remote, the instructions say:

As long as the RTS indicator is green the remote is being held reset and its keypad is inoperative. Click on the RTS
Clear button to turn OFF the green indicator, and note that the remote's indicator flashes twice to indicate it has come
out of reset and resumed normal operation.

I verified the CBL LED flashes twice when I do this, so far so good. But then:

With the green RTS indicator OFF, press the TXD Set Break button, then the RTS Set button, then the RTS Clear
button, and finally the TXD Clear Break button, in that exact order.
You're looking for two indications that this sequence switches the remote out of normal operation mode and into serial
communications mode. The first indication is that the remote's indicator DOES NOT flash twice when reset is removed
by clearing the RTS signal (green RTS indicator turns off). The second indication is that the remote is inoperable and
does not respond to pressing any of its keys.

When I click RTS Clear as part of this sequence, the CBL LED flashes twice. It looks to me like the TXD Set Break didn't work. After that sequence, the buttons on the remote are still functional and typing "I" or "V" does nothing.

I tried plugging in a separate FTDI USB to DB9 COM port adapter with my old JP1.X interface going to the same remote. When I did this, the CBL LED did not flash while doing RTS off/TXD Set Break/RTS Set/RTS Clear/TXD Clear Break. And then I was able to type "I" or "V" and see the expected data come up on the screen.

One more test I tried with the "new" interface... when I put a 100-ohm resistor between pins 4 and 6 without the interface connected to a remote, it echoes the text I type into Realterm. Both the TXD and RXD LEDs flash as I type. Remove the resistor and the text is no longer echoes back, only TXD illuminates. I think this proves the basic functionality of the board and drivers. And I used a small portable scope to prove data is being transmitted on pin 4, not 6, so I don't have those pins switched and they're labeled right on the interface board.

So is this a symptom of the dreaded "counterfeit FTDI chip" I have heard about, or is it possible this is an issue I can resolve somehow? I know the drivers are loaded and virtual COM port is created, but there is something not right about the interface to the remote or the operation of the interface itself.

Thank you!

Just to make sure: The images on the Amazon link show that RTS is not connected to the 6 pin header, but there is a break out via or pad that is labeled RTS. Did you hook that up to the remote? Seems likely since you're seeing the remote going into reset.

Also the images show no labels on the "FT232RL" chip. I think that is quite unusual for for FTDI, so it makes me wonder if this chip is genuine, or perhaps not even a clone of the FT232RL chip. In the past, some non-FTDI chips did not correctly control the break signal, since most RS232 devices don't use it. I think that these days pretty much all USB to 232 chips do handle break correctly, but maybe this one doesn't.

I don't think this is a driver problem: IIRC the symptoms of that were a chip that didn't respond at all. Anyway, I believe that the FTDI driver that would mess up a clone hasn't been distributed in years.

Hey 3FG, thank you for the response.

Here's a pic of my interface. Pink-striped wire is 1. I soldered the connections to the GND, TXD, RXD and RTS holes rather than using the header, although I did also verify the GND, TXD and RXD connections on the header are directly connected to the holes I soldered to: You can also see the chip has an FTDI FT232RL label, but it could still be a fake. I could try putting a little isopropyl alcohol on the label to see if it rubs off. The manufacturer could very well be omitting the label from the Amazon listing so they don't attract attention from FTDI.

I tried downloading the FT_PROG utility and checking it out. It finds the interface and all the info looks good, but I tried changing a couple of settings and reflashing the interface. It looks like a successful flash, no errors, but when I scan again the interface still shows the original settings. Wondering if this is another data point suggesting it's a fake.

I'm leaning towards getting a different interface and trying again. At least I can use the red board for basic serial without breaks or bit banging the RTS/DSR outputs, for some future project.