[solved] Using a FTDI Board to interface JP1

[hjgode]

Hello

sorry for this question, but I am confused on some of the technical infos I find here.

I have a Blaupunkt car DVD player (IVDP-01). The remote is lost and connot be delivered any more. With the help of an universal remote, I found it uses NEC v1 IR protocol. I did an arduino IR sender and receiver and found many codes I can use to control the DVD player.

Now I could build a remote using some tiny arduino, a keypad, a step-up converter and a housing, but that would not look that pretty. The arduino app I wrote is able to send all commands for the DVD using a serail terminal connection to the arduino. But that solution is not usable in a car (a laptop cabled to an arduino box). javascript:emoticon(':(')

Then I baught a Logitech Harmony 300. Unfortunately this remote does alter the learned codes. The codes are changed to similar IR codes in a database at myharmony.com. The IR commands are sent twice or more. Although logitech support was a bit helpful in changing the databse for the DVD player codes, they only changed some of them. I again contacted them to change all codes, they again changed only parts. I gave up with Logitech.

I realized the JP1 remotes and hopefully they only send what I define.

I baught a RCA RCRP05B and now I would like to build a connector cable. I see that most use a pre-made FTDI cable, but I already have a FTDI USB board (http://jeelabs.com/products/usb-bub and http://moderndevice.com/product/usb-bub-ii/).

In various posts here I see some connection instractions, but I am unsure on how to connect the JP1.3 pins to the BUB board:

Code: Select all

JP1 pin definitions:
1 - VCC(U1) (leave unconnected if using batteries)
2 - VCC(U2) (leave unconnected if using batteries)
3 - GND
4 - SDA (U2 data input/output)
5 - input to U1 (unknown function)
6 - SCL (U2 clock)

USB-Serial connection (FTDI):

JP 1.2/1.3      RS232
VDD 1 -
RST 2 <-         7    RTS
GND 3 --         5    GND
RX  4 <-         3    Tx
nc  5 - 
TX  6 ->         2    Rx (Pullup 4k7 to [4] DTR)
                 4    DTR (PullUp to [2])

see FT230X Interface.pdf:

JP 1.2/1.3      FTDI
VDD 1 -
RST 2 <-         RST/RTS/DTR
GND 3 --         GND
RX  4 <-         TX
nc  5 - 
TX  6 ->         RX

Now, what of the above is correct? Can someone correct the last pin-out table above?

Yes, I know and may easier to use one of the semi prebuilt cables, but I would like to use my existing stuff. I am also a hardware guy.

thanks for your help

Josef

[binky123]

I believe it should be

Code: Select all

JP1.3        FT232
RST 2 <--    DTR
GND 3 --     GND
RX  4 <--    TX
nc  5
TX  6 -->    RX

[hjgode]

Many thanks for the answer.

I believe it should be

Code: Select all

JP1.3        FT232
RST 2 <--    DTR
GND 3 --     GND
RX  4 <--    TX
nc  5
TX  6 -->    RX

I found some other 'hints' and your pinout seems OK. I read that every outgoing RS232 signal is good for JP13-Pin2. So not only DTR can be used but also RTS. AFAIK the JP1.x tools support both.

I will check and let you know here (may take some time).

[binky123]

Yes, that is true. We had earlier designs from the JP1.1/JP1.2 remotes that used RTS to reset the remote. The later designs for JP1.3 used DTR.

[hjgode]

Hello

I just would like to confirm that

Code: Select all

JP1.3        FT232
RST 2 <--    DTR
GND 3 --     GND
RX  4 <--    TX
nc  5
TX  6 -->    RX 

works very well.

I just made a simple cable connecting the right pins and tested on Win7x64. The FT232 driver was installed automatically. After changing the virtual serial port to use COM1: and placing the 32bit drivers

Code: Select all

DecodeIR.dll
jp12serial.dll
jp1parallel.dll
jp1usb.dll

in the IR (v804) folder I was able to read and write the RCA RCRP05B remote.

many thanks for assistance

Josef

[3FG]

Yes, that is true. We had earlier designs from the JP1.1/JP1.2 remotes that used RTS to reset the remote. The later designs for JP1.3 used DTR.

I'm surprised by this assertion. I believe that the flash cables sold by both Tommy Tyler and DIY Gadget (Tiao) use the RTS line and not DTR. I've measured the behavior of one of Tommy's interfaces from 2010, and we can also infer the behavior when these cables are used with JP1.4/2/3 remotes. JP12Serial sets up communication with these newer remotes with SetRTS and ClrRTS. JP12Serial does not manipulate DTR for these remotes, yet by now quite a few flash interfaces of both types have been shown to work with JP1.4/2/3 remotes.

It is true that either RTS or DTR may be used with JP1.2 or JP1.3 remotes. As the code is currently written, DTR will not work with JP1.4/2/3 remotes.

So I'm curious: who makes an interface cable that actually uses DTR?

[hjgode]

On my desk I am definitely using the DTR line of the FT232L (at least the pin is labeled with that).

What I found irratic is the jp1xtest app. It is useless within win7 x64. The tool opens and closes a new window very fats and I can not read the output. But more worst is that the CMD window used to launch jp1xtest can not be closed. Neither the close command nor task manager is able to kill the blank window.

[binky123]

I would have to defer to you as I was just glancing through some old code snippets I had regarding jp11Connect(), jp12Connect() and jp13Connect().

I haven't looked at the code in quite a while so it very well could be that I have things reversed and RTS is the preferred method now. Sorry for the confusion.

Yes, that is true. We had earlier designs from the JP1.1/JP1.2 remotes that used RTS to reset the remote. The later designs for JP1.3 used DTR.

I'm surprised by this assertion. I believe that the flash cables sold by both Tommy Tyler and DIY Gadget (Tiao) use the RTS line and not DTR. I've measured the behavior of one of Tommy's interfaces from 2010, and we can also infer the behavior when these cables are used with JP1.4/2/3 remotes. JP12Serial sets up communication with these newer remotes with SetRTS and ClrRTS. JP12Serial does not manipulate DTR for these remotes, yet by now quite a few flash interfaces of both types have been shown to work with JP1.4/2/3 remotes.

It is true that either RTS or DTR may be used with JP1.2 or JP1.3 remotes. As the code is currently written, DTR will not work with JP1.4/2/3 remotes.

So I'm curious: who makes an interface cable that actually uses DTR?

[3FG]

hjgode,
Yes, connecting DTR to the Reset pin will work with JP1.2 and JP1.3 (like the RCRP05B) remotes. Designs done by UEI from roughly 2008 until now are JP1.4 (Samsung processor) or JP2 (Maxim) or JP3 (Maxim). Our software requires the use of RTS with these remotes.

Regarding testing JP1.3 remotes, try following Tommy's instructions to identify a remote's signature using Realterm. If the interface can do that, it is working. I believe that RealTerm will behave under any version of Windows, but it does need to be started with "Run as Administrator".

binky,
At present, JP12Serial first calls jp14Connect(), then jp13Connect(), jp12Connect(), jp11Connect(), and finally JP12OriginalConnect. JP13Connect() and JP12Connect() do both manipulate the DTR line. I believe these routines were added to support the transistor interface in its several guises. However, I believe that all of the USB to Serial interface cables simply use the RTS line. See Tommy's history of the transistor interface. The most recent transistor based cable design also uses RTS.

[hjgode]

Hello

I just tested IR 8.04 with my FTDI adapter and it does only work with DTR connected. If I connect CTS of FTDI to JP1.3 Pin 2 (RST) IR will not recognize the RCRP05B UEI remote.

So that is the tested/working layout for RCRP05B (JP1.3):

Code: Select all

JP1.3        FT232
RST 2 <--    DTR
GND 3 --     GND
RX  4 <--    TX
nc  5
TX  6 -->    RX 

regards

Josef

[Thomas]

Mmm, rather than CTS, try the RTS to pin 2.

Some variants of FTDI chips provide only 3.3 USB level on the signal lines -- I found that my RCRP05B would download OK but balk at uploading anything. Make sure your adapter provides TTL.

And one solution, the UMFT230XB-01, which was suggested as a low-cost alternative, also does not provide a line out for DTR.
Tom

[3FG]

Thomas,
It appears that Josef's FTDI board doesn't support RTS, base on the link he provided. Again, as long as he only interfaces to JP1.2 or JP1.3 remotes, DTR will work.

[Thomas]

We could ask.
Josef, you are using USB BUB II board, it has FT232R, which
has RTS (active low) signal on pin 3 -- would you consider tack soldering a wire on that pin in order to use RTS?

Tom
[edit: finally got my glasses and read the chip markings]

[hjgode]

We could ask.
Josef, you are using USB BUB II board, it has FT232R, which
has RTS (active low) signal on pin 3 -- would you consider tack soldering a wire on that pin in order to use RTS?

Tom
[edit: finally got my glasses and read the chip markings]

Sorry, but these solder points are to small for me to patch them. I will check if I get another FTDI232 USB adapter with all pins at some connectors/patch fields.

[neverhart]

Just wanted to say thanks for this thread, and report this process worked to read my Titan URC-2056 remote (JP1.4) with an Adafruit FTDI Friend and the Mac version of RemoteMaster over USB. I use the FTDI Friend to program Arduinos, and was glad I already had a compatible cable.

For future hackers: the 6 JP1 pins are laid out as follows:
2 4 6
1 3 5

And the connections I used:
JP1 FTDI
1 no connection
2 RTS
3 GND
4 TX
5 no connection
6 RX

The remote's batteries need to be inserted. Hope this helps someone else!