Figure 7. Add a Move block, and wire the output of the Steer
variable to the Steering data hub of the Move block.
So close! It’s time to download our programs and
configure our Bluetooth. Here’s how:
• Download BT_Control_Test to the controller.
66 SERVO 06.2011
Figure 8. Finally, add a Wait For Time block at the very end of
the program, setting it for .1 seconds. This will make sure that
Eddie doesn't try to look for Bluetooth signals too fast, when
they aren't there yet.
• On one NXT, select Search from the Bluetooth menu.
When the other NXT shows up in the search results,
select it and connect.
• Now both devices are connected. If either one is
turned off, you’ll have to re-establish the connection
by going into Bluetooth > My Contacts, and selecting
the other NXT.
• Run the control program on the remote control, and
the bot program on Eddie.
If all goes well, pressing the orange Enter button on
the controller should make Eddie move forward; either
arrow should make him turn in the specified direction; and
holding the touch sensor should make him stop in place
until it’s released.
We just learned how to connect two NXTs via
Bluetooth, and make one act as a remote control for the
other. In the next edition of The NXT Big Thing, we’ll take
Bluetooth control even further — so stay tuned!
In the meantime, here’s a few cool challenge ideas for
you to keep your brain in gear:
• Make Eddie’s remote use a variety of sensors instead
of the NXT buttons.
Greg "LEGO" Intermaggio lives in the Bay
Area, CA, where he runs a business
called Techsplosion, bringing hands-on
science to all ages and walks of life. In
his spare time, Greg likes to unicycle,
juggle, unicycle juggle, and battle killer
robots! More information about Greg can
be found at Intermaggio.com. More
information about Techsplosion can be
found at Techsplosion.org