This is EXACTLY why I logged on today.  I need the same cable. I thought Dell would have one and called Parts. The person I spoke to tried very hard to argue with me that what I wanted was a VGA cable, not a Serial cable and I have up and hung up.

I 'think' the little picture is the jack side (on the projector), but I have had no luck trying to build a cable. I'm using Girder to try to control the projector with the Serial plug-in.

No luck so far.

Tom

Hi, Folks-

I've had some success controlling the Dell 4100mp through the RS2232 port with some custom software I'm writing. This has involved building a cable and figuring out how to set the CRC on the data packets. This information is provided with NO WARRANTY; if you mess up your projector it is your responsibility.

Cable:

The mini DIN plug on the projector is the same as that on a PC mouse or keyboard. I found the appropriate plug at Fry's electronics and wired it up as follows: (Note that the picture in the manual is what you see when you look at the back of the projector)

PC DB-9 Dell 4100mp
Signal Pin# Signal (Don't know pin numbers)

RD 2 TxD
TD 3 RxD
GND 5 Gnd (both)

You could probably also buy a mouse or keyboard extension cable, cut the socket end off and wire it up to a DB-9. You'd have to use a meter or test light to figure out which wires in the cable went to the desired pins on the projector.

Protocol/CRC:

The entries in the manual are pretty unhelpful. They specify that each packet must have a CRC, but don't tell you how to calculate it. I found the following link on the internet that had some C source for calculating a CRC for a different brand of projector, and that seemed to work:

http://www.digitalprojection.com/Documents/RS232%20protocol%20and%20command%20structure.pdf

Here is another link to a similar document:

http://www.cs.unc.edu/Research/stc/FAQs/Projectors/ProjectionDesign/F1_RS232_rev1.5print.pdf

After CRC'ing the packets with these algorithms, I was able to successfully execute the commands in the manual. Here is a list of the CRC values for each command, and all bytes for that command in the correct order:

POWER 0xffc6 {0xbe,0xef,0x10,0x05,0x00,0xc6,0xff,0x11,0x11,0x01,0x00,0x01}
MENU 0xbfc7 {0xbe,0xef,0x10,0x05,0x00,0xc7,0xbf,0x11,0x11,0x01,0x00,0x02}
UP 0x7e07 {0xbe,0xef,0x10,0x05,0x00,0x07,0x7e,0x11,0x11,0x01,0x00,0x03}
DOWN 0x3fc5 {0xbe,0xef,0x10,0x05,0x00,0xc5,0x3f,0x11,0x11,0x01,0x00,0x04}
LEFT 0xfe05 {0xbe,0xef,0x10,0x05,0x00,0x05,0xfe,0x11,0x11,0x01,0x00,0x05}
RIGHT 0xbe04 {0xbe,0xef,0x10,0x05,0x00,0x04,0xbe,0x11,0x11,0x01,0x00,0x06}
RSYNC 0x7fc4 {0xbe,0xef,0x10,0x05,0x00,0xc4,0x7f,0x11,0x11,0x01,0x00,0x07}
SOURCE 0x3fc0 {0xbe,0xef,0x10,0x05,0x00,0xc0,0x3f,0x11,0x11,0x01,0x00,0x08}
VOLUP 0xfe00 {0xbe,0xef,0x10,0x05,0x00,0x00,0xfe,0x11,0x11,0x01,0x00,0x09}
VOLDN 0xbe01 {0xbe,0xef,0x10,0x05,0x00,0x01,0xbe,0x11,0x11,0x01,0x00,0x0a}
ZOOMIN 0x7fc1 {0xbe,0xef,0x10,0x05,0x00,0xc1,0x7f,0x11,0x11,0x01,0x00,0x0b}
ZOOMOUT 0x3e03 {0xbe,0xef,0x10,0x05,0x00,0x03,0x3e,0x11,0x11,0x01,0x00,0x0c}
MUTE 0xffc3 {0xbe,0xef,0x10,0x05,0x00,0xc3,0xff,0x11,0x11,0x01,0x00,0x0d}
FREEZE 0xbfc2 {0xbe,0xef,0x10,0x05,0x00,0xc2,0xbf,0x11,0x11,0x01,0x00,0x0e}
HIDE 0x7e02 {0xbe,0xef,0x10,0x05,0x00,0x02,0x7e,0x11,0x11,0x01,0x00,0x0f}
VIDMODE 0x3fca {0xbe,0xef,0x10,0x05,0x00,0xca,0x3f,0x11,0x11,0x01,0x00,0x10}
HKEYSTUP 0xfe0a {0xbe,0xef,0x10,0x05,0x00,0x0a,0xfe,0x11,0x11,0x01,0x00,0x11}
HKEYSTDN 0xbe0b {0xbe,0xef,0x10,0x05,0x00,0x0b,0xbe,0x11,0x11,0x01,0x00,0x12}
VKEYSTUP 0x7fcb {0xbe,0xef,0x10,0x05,0x00,0xcb,0x7f,0x11,0x11,0x01,0x00,0x13}
VKEYSTDN 0x3e09 {0xbe,0xef,0x10,0x05,0x00,0x09,0x3e,0x11,0x11,0x01,0x00,0x14}
PIPONOFF 0xffc9 {0xbe,0xef,0x10,0x05,0x00,0xc9,0xff,0x11,0x11,0x01,0x00,0x15}
PIPSWAP 0xbfc8 {0xbe,0xef,0x10,0x05,0x00,0xc8,0xbf,0x11,0x11,0x01,0x00,0x16}
ASPECT 0x7e08 {0xbe,0xef,0x10,0x05,0x00,0x08,0x7e,0x11,0x11,0x01,0x00,0x17}

Actually controlling the projector:

Unfortunately, these commands do the exact same thing as pushing the buttons on the remote control. So, for example, if you use the source command it just switches to the next source input. If your program doesn't know what input was active before, you don't know what input you are going to switch to. This means that you can't write a program to "SelectNTSC" for example.

Because of the way the power button works you have more control over the power. A single power command will turn the projector on, and two power commands seperated by a short gap are required to turn the projector off. So, if you send a single power command you are guaranteed to turn the projector on. If you know that it is on, sending two power commands in quick succession will turn the projector off.

If you look at the above listed documents you will see that there is a lot mor control over those projectors. You can turn them on with one command and off with another. You can also select specific inputs.

(Another document I found with control commands for a different projector is here: http://prickartz.medium.de/downloads/pages/RS232Protokolle/BenQ/benq_protocol_pb2120_1000pb2120.doc)

All these projectors are DLP (digital light processing) models made with Texas Instruments chipsets. I am hoping that some of their commands will also work with the Dell 4100mp. I haven't had any luck yet, but if I figure something else out I'll post it here.

Max Behensky

Hi, again-

The formatting on my cable schematic got messed up. Here is a better version:

PC DB9 Pin#......4100mp (Don't know pin numbers)

RD.......3.........TxD
TD.......3.........RxD
GND....5.........Gnd (both)

This is great! Thanks - I've been trying, but unsuccesfully.

I'm not sure I understand as it says pin 3 twice.   Are thos the DB9 pins?

I'll try the commands too.

Tom

Hi, Tom-

My first post was correct, my reformatted one wrong. Here's the correct wiring again:

Connect pin 2 (RD) on the DB9 connector to TxD on the Dell 4100MP.
Connect pin 3 (TD) on the DB9 connector to RxD on the Dell 4100MP.
Connect pin 5 (SGND) on the DB9 connector to both grounds on the Dell 4100MP.

Good luck..

Max Behensky

Here ya go fellas, by the way after a little searching at dell I found a pdf with the ENTIRE command string.  I don't know why it wasn't in the manual,  for some reason I can't find the link now.  Here is some very useful information including a few pin diagrams.  I will post it if I find it.  It contained all missing info in the manual.

http://www.lammertbies.nl/comm/cable/RS-232.html

Connections are as follows (these are typical settings on both ends).

db9  ------------------------> miniDin

(TX)  3 ---------------------------------> (RX)

(RX) 2 ----------------------------------> (TX)

(GD) 5 -----------------------------------> (GD)

The mini Din Diagram is as follows (From Solder side)

Male End - solderside        

      o      H      TX

 o                     RX

         o      GD        

 

The DB9 is as follows female:  (solderSide)

1   2   3   4   5

   6   7   8   9

HTH

Pin order on a miniDin is usually (solderSide)

        6 (external carry)   H     5 (Rx 1200)

4 (Rx 9600)                                 3 (PTT/RTS)

    2(GD)                              1(TX)

   

-S

 

Found it fellas.  Here is the link to the page at Dell support

 

HTH

Hi, spharis-

If you have a copy of that pdf file you found at Dell (maybe it is in your browser cache directory if nowhere else??) could you email it to me? My email address is maxb@twinlanes.com.

Thanks,

Max Behensky