Synthesize-your-own NXT® connector plug

The LEGO NXT kit uses connector that are very similar to regular telephone plugs. For safety reasons, LEGO could not use telephone plug, so they chosen a variant with the latch offset to the right side. Unfortunately, this connector is not available anywhere, even if yet another version (called "DEC" connector) can be easily found... but with the latch on the wrong side!





Mindsensors now sells NXT-style RJ12 connectors!
Warning: You will need to customize a regular RJ12 crimping tool (for example this low cost one) to use these connectors. More on this when I have hacked mine!




...and they also offer NXT compatible sockets to build your own NXT compatible devices.
Warning: contrarily to most RJ sockets, pins have two staggered lines of 2mm pitch pins (instead of 2.54mm pitch).



As NXT cables were in short supply, and as I wanted to experiment with the new sensors and motors, I crafted a few connectors from regular RJ-12 phone connectors... here is how. I have converted about 10 connectors, it's rather easy if you have the right tool and are reasonably skilled. I can now convert a connector in less than 5 minutes (glue curing time not included)...

We start with a regular RJ-12 plug, already crimped on its cable (plugs, cable and inexpensive crimping tools are available from many electronics shops). The plug and cable must have 6 wires available, and to follow LEGO color coding, it's better that the wires color order (from left to right) be blue/yellow/green/red/black/white.
Warning: If you crimp your connectors, it's better to verify that the contacts between wires and connector are good before converting the plug!

If you compare a RJ-12 plug to a NXT plug, there are two differences:
the latch must be moved to the right of fhe connector
RJ-12 latch is wider and will need to be shrunk to match NXT latch size.
The tongue of the latch is also wider on the RJ-12 plug, but since it fits the NXT socket, it doesn't matter.

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