At the Hamvention fleamarket, Dustin got an amazing price on a Handheld Products 3800r barcode scanner, probably because the cable wasn’t included. The connector on the bottom of the scanner is a nonstandard 10p10c (aka RJ50), so most folks wouldn’t just be able to make one, but buying a $57 cable for a $1 scanner seemed silly. Further frustrating the situation is that Handheld (acquired by Honeywell) is pretty tight-lipped about certain info. The pinout for the RS232 cable (p/n 42206300) was easy enough to find, but the innards of the USB cable (p/n 42206161 or 42206203) proved elusive.
Luckily for Dustin’s iTrackMine habit, i3′s electronics lab had a set of 10p10c crimpers and a box of connectors (and a resourceful mentor geek), waiting to solve just such a problem. After building a little 10p10c breakout cable and a USB breakout cable, some breadboard jumper wires made it relatively straightforward to investigate every permutation until the device enumerated. (Note that ‘straightforward’ does not equate to ‘quick’.)
For the purpose of saving some hapless future scanner technician some time, the pinout is as follows:
|USB pin number||function||color||10p10c pin number|
Two construction tips:
First, it’s difficult to position the wires in a modular connector if you’re not using every position. Stuffing the unused ones with little stubs of wire made it easy to guide the relevant wires into position.
Second, modular connectors can be reinforced by flooding the back with hot-melt glue. (This works very well on cat-5 patch cords.) Since this build used a flexible, thin USB cable in a giant 10p10c connector, the glue is the only reason it didn’t fall right out.