USB Phone Cable for JP1.x

[cerulean]

Hi All,

Sorry if this is covered somewhere, but I've searched and can't find a definite answer.

I have a PL2303 based phone cable that I use to communicate with devices that have a TTL level serial port using Rx, Tx and ground. I see references in posts that a PL2303 based phone cable will work with a JP1.x remote (RS 15-100, in my case). Are the signals that the JP1.x remotes expect just TTL level serial signals (Rx, Tx, ground, DTR and RTS)? Or do I still need RS-232 level signals and the circuit in the JP1.x interface?

Thanks,
Bob

[classicsat]

In theory, perhaps. You need the proper other control line as well though..

[cerulean]

In theory, perhaps. You need the proper other control line as well though..

OK. I got this working (sort of). The problem is that the DTR line looks like it has the opposite states that IR.exe (and the test program) expect. I did up a VB app that sends the same codes to the remote that the tester program does and I get back the correct responses from the remote if I swap the Clears and Sets for DTR.

I think that I'll post in the software forum to see if it would be possible for IR.exe to try DTR both ways when looking for a JP1.x "cable".

-Bob

[binky123]

Do you have a rough diagram of what pins connect where? I believe you can use RTS instead of DTR for the /RESET function.

[cerulean]

Do you have a rough diagram of what pins connect where? I believe you can use RTS instead of DTR for the /RESET function.

I did try using RTS instead of DTR. It worked for the test program, but IR.exe (version 7.07) still couldn't see the interface.

[binky123]

Do you have a diagram of the pinouts you are using? The original JP1.2 design used RTS as the /RESET line. Do you see the LED blink twice? If so, that at least means the /RESET line is working on your circuit. Are you using IDC-5? What type of remote are you using(JP1.2 or JP1.3)?

[cerulean]

Do you have a diagram of the pinouts you are using? The original JP1.2 design used RTS as the /RESET line. Do you see the LED blink twice? If so, that at least means the /RESET line is working on your circuit. Are you using IDC-5? What type of remote are you using(JP1.2 or JP1.3)?

I'm building everything per the RS 15-100 mod by Tommy Tyler (NC for IDC 5). I guess that I'm attempting to build a JP1.3 cable. I'm using only Rx, Tx, ground, and DTR. I don't need power since the cable/circuit (PL2303) is powered from the USB port.

[binky123]

I looked at the PL2303HX datasheet and I believe your circuit is like this:

Code: Select all

PL2303        IDC-6
1  TXD   ---- 4 Data-In
2  DTR_N ---- 2 /RESET
3  RTS_N ---- 2 /RESET
5  RXD   ---- 6 Data-Out
18 GND   ---- 3 GND

The current jp12serial.dll version 0.06 driver does a CLRDTR(OFF/+10V/1) and then a SETDTR(ON/-10V/0) for the current JP1.2 design. If a JP1.2 remote is not detected, it tries SETRTS(ON/-10V/0) and then a CLRRTS(OFF/+10V/1) for the original design. So hooking DTR_N or RTS_N to IDC-2 should generate a RESET of the remote.

You might try replacing the jp12serial.dll v0.06 with the one from tester and give that a try.

You should be able to see the LED flash twice if the /RESET line is working. I think there are some tests to verify the /RESET line/circuit is working.

[Tommy Tyler]

cerulean,

binky123 asked twice what pinout you were using, and I don't see any response. It's hard to help when you don't answer simple questions.

I guess that I'm attempting to build a JP1.3 cable. I'm using only Rx, Tx, ground, and DTR. I don't need power since the cable/circuit (PL2303) is powered from the USB port.

There is no such thing as a "JP1.3 cable". You can use a JP1.2 cable on a JP1.3 remote by disabling pin 5, but it is still a JP1.2 cable. And I'm not sure what you mean by "don't need power". What do you use to pullup the Rx and RESET signal lines to the remote?

[cerulean]

I looked at the PL2303HX datasheet and I believe your circuit is like this:

Code: Select all

PL2303        IDC-6
1  TXD   ---- 4 Data-In
2  DTR_N ---- 2 /RESET
3  RTS_N ---- 2 /RESET
5  RXD   ---- 6 Data-Out
18 GND   ---- 3 GND

The current jp12serial.dll version 0.06 driver does a CLRDTR(OFF/+10V/1) and then a SETDTR(ON/-10V/0) for the current JP1.2 design. If a JP1.2 remote is not detected, it tries SETRTS(ON/-10V/0) and then a CLRRTS(OFF/+10V/1) for the original design. So hooking DTR_N or RTS_N to IDC-2 should generate a RESET of the remote.

You might try replacing the jp12serial.dll v0.06 with the one from tester and give that a try.

You should be able to see the LED flash twice if the /RESET line is working. I think there are some tests to verify the /RESET line/circuit is working.

Sorry for the long delay in my response.

This is what my original pin out looked like (only four wires):

Code: Select all

         PL2303          IDC-6 
         1  TXD   ----   4 Data-In 
         2  DTR_N ----   2 /RESET 
         5  RXD   ----   6 Data-Out 
         Shield   ----   3 GND

This seemed to have the wrong "polarity" for DTR. I wrote up a VB6 app to experiment with and I could Set the DTR line and put Tx into Break so that I could reset the remote and get back the signature from the remote. But neither tester or IR would work with this pinout.

I then tried replacing DTR with RTS (four wires):

Code: Select all

         PL2303          IDC-6 
         1  TXD   ----   4 Data-In 
         3  RTS_N ----   2 /RESET 
         5  RXD   ----   6 Data-Out 
         Shield   ----   3 GND

This worked with tester, but not with IR. Again by slightly modifying my VB6 application, I could reset the remote and get the remote's signature.

I had put my cable back to my original pinount (and posted in the software forum looking for a possible change to IR), but after your post I put it back to the pinout with RTS instead of DTR. Then I renamed the DLL from the tester app and dropped it into my IR7.07 directory. That did the trick. After I downloaded the RDF file for the RS15-100 and put it in the IR7.07 directory, IR7.07 initializes my cable and recognizes my remote.

Thank you for the suggestion about the DLL.

And I'm not sure what you mean by "don't need power". What do you use to pullup the Rx and RESET signal lines to the remote?

I'm not using anything to pull up the Rx and RESET signals. I'm trying to use an off-the-shelf cellphone data cable. After reading your most excellent RS15-100 mod instructions, it looked like the remote was using TTL level serial communications. I had a USB to TTL serial cable that I use when I've needed a serial console for Linux based appliances. I wanted to see if I could use the same cable with the RS15-100 remote, so I bought and modded the remote. Then I started experimenting with the cable which I originally bought at RS 5 or 6 years ago to program my wife's Motorola 720 cell phone.

Since this seems to work with four wires, if I do this again, I'll probably use a 4 conductor phono plug and socket (similar to my old RS15-1993's and RS15-2103).

-Bob

[binky123]

Good to hear you got it working. Are you able to see(serial port logging software) what is causing the difference between the two jp12serial.dll drivers?

[cerulean]

Good to hear you got it working.

I may have spoken too soon. I can't write to the remote. I need to look at it some more. I have to read up on the RS15-100 to see if I have the latest RDF and if there are any special requirements.

Are you able to see(serial port logging software) what is causing the difference between the two jp12serial.dll drivers?

I've been using Portmon from SysInternals for my debug, but I haven't compared the two DLL's. I'll try to compare the two using tester, but it probably won't be until this weekend.

Can you give me the interface definition to the DLL so I can experiment with it from my VB app? I can see the function names with dependency walker, but it doesn't give me return types and parameters.

[binky123]

I've released IR7.08 which includes an updated jp12serial.dll that handles a JP1.3 remote using the original JP1.2 design(/RESET on RTS pin). You should be able to use this driver with your RS 15-100 JP1.3 remote and the PL2303 chip. This driver also handles serial COM ports greater than COM9.

[Capn Trips]

I've released IR7.08 which includes an updated jp12serial.dll that handles a JP1.3 remote using the original JP1.2 design(/RESET on RTS pin). You should be able to use this driver with your RS 15-100 JP1.3 remote and the PL2303 chip. This driver also handles serial COM ports greater than COM9.

Binky,
Does this mean that Tommy's workaround of cutting off pin 5 of a JP1.3 remote no longer pertains?

[binky123]

No, that is still relevant for the current JP1.x design which assumes the MCU /RESET line is on the DTR line. The issue here was that the DTR_N signal coming from the PL2303 chip was inverted. The original JP1.2 design used RTS and different logic to reset the MCU so I suggested he hook up his RTS_N line to the MCU /RESET line. The original design JP1.2 design used SETRTS and then CLRRTS to reset the MCU which is what he needed.

The pin 5 issue is only relevant if you have a JP1.X cable for use with JP1.1 remotes. If you have a JP1.2 cable, there is no connection on IDC-5 so no need to do anything. Pin 5 is used for BDM and Tool mode for the JP1.2 and JP1.3 remotes which is not relevant for our purposes.