Trying It Out
Here’s the payoff to all your hard work: You
finally get to see the little kart zoom around your living room.
Remove any obstacles before you start!
Follow these steps to operate your go-kart:
1. Slip in the batteries.
2. Turn on the power switch on the kart.
3. Point the transmitter at the kart and press
and release the on/off button.
4. Watch it go!
If nothing happens, here are a few things to
check out:
All
the batteries are fresh, are tight in the battery pack, and face
the right direction.
See
whether any wires or parts have come loose.
Compare your circuit with the photos in this chapter to make
sure you got all the connections
right.
To turn left, press and release the motor L
button; to turn right, press and release the motor R button.
After the kart has turned far enough, press and release the same
button again, and the kart will go forward. If you want the kart
to go backward, just press and release motor button L and
quickly press and release motor button R (or vise versa); ditto
if the kart is moving backward and you want it to move forward.
If these buttons work opposite to the way you
expect, swap the wires from the motors at the terminal blocks on
the receiver.
Just like your car on a cold winter morning, the
kart could take a few moments to warm up. Wait a few beats after
you turn on both on/off switches, and then go for it!
If you plan on keeping the kart working
long-term (rather than using the parts on another project), we
suggest that you remove the Velcro from the motors and from the
base (where you mounted the motors) and glue the motors to the
kart base at the same spot. This will make the kart a little
more stable. You can also glue the wheels onto the motor shaft
to make your kart more permanent.
Taking It Further
Are you so wowed by the go-kart you want to add
to it? Here are some ideas to explore:
Other encoder/decoder ICs are available that have more than the
three input/output pins used here.
One option is the Holtek HT12A encoder
and HT12D decoder; another is Reynolds Electronics IR-DX8
encoder/ decoder. Building a kart
by using one of these lets you add other things to the kart that
you can control: for example, LED headlights or a buzzer
to use just like a car horn.
If
you want to race go-karts with a friend, you can build multiple
karts with one of the other encoder/decoder pairs just
mentioned. These allow you to pick
an address for each kart by tying different pins to
ground or +V on each of the encoder/decoder pairs.
However, you still have to be careful not to activate your
transmitters at the same time or
point your transmitter at your buddy’s car lest you confuse the
receivers.
The only way around this is to use radio control
instead of infrared control, and use different frequencies for
each transmitter. See Chapter 18 for information about using
radio control.
Spiff up the go-kart base and top any way your artistic whim
dictates:
Paint it, add racing stripes, use a different
shape, add decals, or glue fuzzy fur and cute little ears on it.