Electronics_Projects_For_Dummies

Chapter 11: Controlling a Go-Kart, Infrared Style 251

2.Place five terminal blocks on the breadboard, as shown in Figure 11-9.

The five terminal bocks shown in this figure will be used to connect two wires each to various components in the circuit. The wires go to the battery pack, IR LED, on/off switch, motor R switch, and motor L switch, respectively.

Figure 11-9:

Add terminal blocks to the

breadboard.

3.Insert wires to connect each component and terminal to the ground bus and insert a wire between the two ground buses to connect them,

as shown in Figure 11-10.

On the resonator, the center of the three leads is the ground lead.

Eight shorter wires connect components to ground bus; the long wire on the left connects the two ground buses.

Chapter 11: Controlling a Go-Kart, Infrared Style 253

5.Insert wires to connect the encoder IC, voltage regulator, and resonator, as shown in Figure 11-12.

IC Pin 3 to the other outer resonator pin

Figure 11-12:

Connect the IC, voltage regulator, and resonator.

6.Insert wires to connect the terminal blocks to the IC1 encoder and resistor, as shown in Figure 11-13.

254 Part III: Let There Be Light

Figure 11-13:

Connect terminal blocks to the IC1 encoder and resistor.

Pin 4 of IC1 encoder to motor L terminal block Pin 6 of IC1 encoder to motor R terminal block

7.Drill holes in the transmitter box for the LED and switches.

Figure 11-14 shows holes drilled in the front of the box for the LED and in the top of the box for the switches. The size of drill bit that you use depends upon the diameter of the switches and LED socket you use. We used a 1⁄4" drill bit to drill the hole for the LED and a 5⁄16" drill bit to drill the holes for the switches.

Chapter 11: Controlling a Go-Kart, Infrared Style 255

Figure 11-14:

Drill holes for the LED and switches.

8.Place adhesive-backed Velcro in the box and on the battery pack, as shown in Figure 11-15.

Figure 11-15:

Stick Velcro to attach the battery pack.

256 Part III: Let There Be Light

9.Place the three switches through the holes, as shown in Figure 11-16, and secure them to the box with the nuts included with the switches.

Figure 11-16:

Transmitter box with switches installed.

10.Feed the LED socket through the hole in the front of the box. Slip the LED into the socket from the inside of the box, and then slip the bottom half of the socket over the leads and tighten to secure the LED.

11.Connect one black and one red 6" wire to the LED and solder them.

The secured and soldered LED is shown in Figure 11-17.

The red wire must be connected to the longer of the LED leads. After the wires have cooled, wrap them in electrical tape to prevent the leads from shorting.

Heed all the safety precautions about soldering that we talk about in Chapter 2. For example, don’t leave your soldering iron on and unattended. And for heaven sakes — don’t drop it in your lap when it’s hot!

Chapter 11: Controlling a Go-Kart, Infrared Style 257

Figure 11-17:

Transmitter

box with

LED in

place.

12.Connect 6" wires (any color is okay) to the switches and solder them, as shown in Figure 11-18.

To connect wires to the switches, feed the wire through the lug and twist to secure it.

Figure 11-18:

Attach wires to the switches.

258 Part III: Let There Be Light

13.Secure the breadboard in the box with Velcro. Or, if the breadboard already has adhesive tape on the back like the one we used, just use the tape.

14.Attach the wires from the battery pack snap connector and the LED to the terminal blocks, as shown in Figure 11-19.

Figure 11-19:

Transmitter box with breadboard installed.

15.Attach the wires from the switches to the terminal blocks, as shown in Figure 11-20.

Chapter 11: Controlling a Go-Kart, Infrared Style 259

Leads to on/off switch Leads to motor R switch

Figure 11-20:

Attaching wires to terminal blocks.

Leads to motor L switch

16.Place batteries in the battery holder, connect the snap, and secure the holder in the box with Velcro, as shown in Figure 11-21.

Figure 11-21:

The inside of the completed transmitter box.