USB Pin-out
The 920 has a standard mini-USB "B" connector. The pin-out is available here:
http://pinouts.ru/Devices/mini-USB_pinout.shtml. I'm not sure, but you might need to reverse the Data+/Data-, since both the camera and the TomTom are considered "peripheral" devices.
You would need to write and install a program to read the data and display on the TomTom. I don't know anything about that.
There are other issues to consider:
- Does the TomTom actually provide the +5V output needed to power a camera? I suspect not. You might resolve this by splitting the power-supply cable into a Y-cable, with one end providing power to the TomTom and the other bringing power and data to a female connector for the camera.
- Can the TomTom be set to read data while not in "connect to computer" mode?
- Can the TomTom be set to read data while not in "connect to computer" mode?
- The maximum USB cable distance is 4m (~12ft). This would make cable routing difficult in most vehicles. Distance can be extended through the use of a USB hub, but even 8m might be cutting it close for a clean, permanent installation.
What would be really nice is a TomTom unit with a built-in 2.4GHz video receiver for one of the readily-available wireless back-up cameras sold on eBay and elsewhere.
And, if you're accepting wish-list items, a partnership between TomTom and Valentine-1 to provide radar/laser detection with visual location indication on the display.
And please, please, please, a bigger, more accurate POI database with better search capabilities.
We're probably now talking about a device costing $800 (US), but it would clean my dashboard of everything except the TomTom.