This howto demonstrates how the Solar Panel adapter for the dSolar can be used to power the NXTBee Pro or the WIFI.  One might want to use this setup to power a long-range vehicle or autonomous vehicle that communicates information back to a computer or another NXT.

First up, you’ll need a few items.

9v battery wire:

RJ-45 cable (regular household telephone wire).  I used about 0.5m but the length can vary based on the needs of your design:

Wire trimmers:

Soldering gun + solder:

OR 2xbutt connectors:

Electrical tape

Now that we’ve got that together, we can get started!

First, trim the battery coupling off of the 9v battery wire, like this:

Strip a small bit (10 mm) of protective coating off the red and black wire ends.

Now cut off one end of the RJ-45 cable.  Strip 2cm of the outer protective coating off.  There should be 4 colored wires within.

Now look at the other end, with the RJ-45 connector still attached.  Our view is top-down, from the back.  The middle wires aren’t needed, and can be cut down to the outer coating on the other side.  The leftmost wire is positive (in this case, yellow), and pairs with the red 9v wire.  The right is negative (in this case, black) and pairs with the black 9v wire.

Strip the ends of the these interior telephone wires.  Now you’re ready to attach the two cables to each other.  If you solder the ends together, make sure to work in a well-ventilated area, open windows or fans are good here.  I usually splice the ends before soldering so they won’t separate before the solder cools.

If you use this method, wrap the joints separately in electrical tape once they cool.  This prevents shorting the connection while your cool LEGO MINDSTORMS creation is moving around.

If you use butt connectors, make sure to really mash down hard to get a good connection.  This joint is weak to pulling on the ends so you may want to tape it if there’s any foreseeable strain.

Now we’re done!  I get a lot of good strong sunlight in the afternoon so I can power the NXT unit and an NXTBee Pro or a WIFI unit with one 4w solar panel using a parallel.  If you get less direct sunlight, or if you have motors or extra sensors to run, you’ll probably need an extra panel to power everything.

If you have any questions or comments, please contact me at adam <at> dexterindustries <dot> com.