I've just modified a Motorola cell phone serial programming cable (Model NKN6560 http://www.google.com/search?hl=en&q...=Google+Search ), to interface with my Thera. I also spliced-in a USB cable so that I could have the best of both worlds.

Essentially, the RS232 to LVTTL interface board in this cable is powered from the Thera's sync connector (3.3 volt source on pin 2).

In building this project, I discovered that you need to place a power switch so that you can shut off the serial interface in the cable. If you don't shut the RS232 converter off, the Thera will sense there is a live RS232 interface when you plug in the cable and it will force the Thera to use the only serial activesync interface. I tried a number of ways to force the Thera to default to USB but none worked. I tried deleting all serial interfaces from the registry but this just produced an activesync error and the unit refused to connect to anything.

After adding the power switch, I was able to verify that with the power to the converter board turned-off, it connected to the USB interface 100% of the time. After pulling the cable out and turning the level converter power back on caused the Thera to auto-switch to the serial interface to sync when the cable is re-inserted.

For those who want to modify one of these Motorola cables (Model NKN6560), please refer to my earlier posts in http://www.pdaphonehome.com/forums/s...0&pagenumber=3 4th entry down, for the pinouts and the exact USB cable (and source) that I used.

I will try to get a few photos and details posted if I have time, but you're all on your own to build this.

Note, if all you own is a Weller Soldering gun, don't even think of building this cable. You need need very good soldering skills/experience and a needle-tip soldering iron to put this together.

Lastly, the reason I built this was to interface my GPS and OBD-II interface to the Thera. I also wanted to be able to charge/power the thera while in the car. So I reused the Motorola serial interface cable and added the USB sync/charging cable I picked up off of Ebay. The charging cable came with the cigarette lighter USB charger interface.

Here is a short document I wrote that gives the wiring information for the cable.

I have pictures of the cable, but have to shrink them down. Will post shortly.

10/6/04 Edit: Updated the document slightly.

Attached Files

motorola to thera pinouts.zip (4.8 KB, 264 views)

Here are the photos of my cable. I tried to upload the individual photos but they were too large, so I put them into a zip file.

Attached Files

photos.zip (425.8 KB, 312 views)