OK, It took two evenings instead of one, but my thoroughness paid off. The touch screen worked perfectly the first time I plugged it in! Here's the scoop:
1. Ignore all the technical documentation that comes on the CD. The controller that came with my touchscreen was different than all of the various controllers covered in the documentation.
2. Pull off the power connector with the bare red and black wires. You won't need it. There is also a black chassis ground wire with a little metal ring at the end. You don't need it so desolder it or just cut it off.
3. You will need to modify the controller's serial logic to work with the i-opener. The controller uses RS232 level voltages but the i-opener expects TTL level (5v) signals. The i-opener's Tx and Rx lines are also inverted logically compared to the controller's RS232 Tx and Rx lines. Luckily this is a really easy mod. All you need to do is bypass the RS232 line driver chip on the touchscreen controller. The serial Tx and Rx lines coming out of the touchscreen's microcontroller are exactly what the i-opener needs.
You don't need to remove the line driver chip to bypass it. I made a total mess of things removing the chip (pulled up three pads and parts of two traces) only to learn that I could have gotten away with simply cutting 4 traces. So learn from my mistake and leave the line driver chip in it's place.
The line driver is a LT1381 http://www.linear-tech.com/prod/datasheet.html?datasheet=68. You'll need to look at the datasheet and study the board to make sense of these directions (sorry I don't have a camera to post pictures). Cut the traces leading to pins 7,8,9,10 of the LT1381. These traces are pretty easy to find. You will probably need a multi-meter though because some traces run under the chip and cannot be followed visually. Once you've cut the traces, connect a jumper wire from the trace that went to pin 7 to the trace that went to pin 10 (bypassing the LT1381 Tx driver). Connect a second jumper wire from the trace that went to pin 8 to the trace that went to pin 9 (bypassing the Rx driver). After this mod is complete, pins 7,8,9,10 of the LT1381 should connect to nothing. The easiest way to connect the jumper wires is to find a via hole along the trace, poke a wire-wrap wire through the hole, and solder it. You will need to lightly scrape the protective coating off the via hole on the bottom of the board to make a contact point for the solder.
Great! now the controller board is ready to go. We just need to connect it to the i-opener.
4. Cut the DB9 end off of the COM cable leaving enough wire to run from CN12 to where you will mount the controller board. I know, it pained me too, cutting such a nice cable, but it has to be done. Strip the outer rubber tube and shield braid off the wire freeing the inner colored wires. You will only need 4 wires, the Blue (5v), Orange (Gnd), Red (Rx), and Brown (Tx). You can remove the extra wires by lifting the tabs on the Molex connector and pulling the wires out. It's a really screwy color scheme and I don't trust it to stay consistent so for a sanity check: on the Molex connector Blue is pin 9, Orange pin 5, Red pin 3, Brown pin 2. Pin 1 on the Molex connector has a square solder pad.
Run the 4 COM cable wires to CN12 in the i-opener as follows:
Blue - pin 10 (+5v)
Orange - pin 9 (gnd)
Brown - pin 2 (connects controller's Tx to i-opener's Rx)
Red - pin 1 (connects controller's Rx to i-opener's Tx)
Don't have anything handy to connect to the CN12 header? I came up with a solution that worked pretty well. Strip about 4mm from the end of each of the colored wires. Next get a piece of slightly bigger wire (22 awg worked perfectly) and strip 8mm sections of insulation off. Push a piece of the 22awg insulation onto the end of each colored wire, until the bare end of the colored wire just pokes out of the 22awg insulation. You can now press the newly insulated end of each colored wire over a pin of CN12. The 22awg insulation will grip the pin and hold the bare end of the wire in contact.
That's it! Turn on the i-opener and install the touchscreen drivers. If you want to verify that the panel is working, you can use HyperTerminal at 9600 baud. Each time you touch the touchscreen, you will get a bunch of "garbage" characters in HyperTerminal.
NOTE: I learned tonight that there is a "top" and "bottom" of the touchscreen. With the touch side up, the control cable should come out of the right side of the screen. If you try to use the screen upside-down, the calibration won't work.
