| Intermediate Technology Education | Control Technology | Pre-Design | Topic 3 | Activity 8 |
Computer Control Systems
The following example illustrates basic computer control components and concepts. An explanation follows the figure.
Explanation
This module uses the following computer control components. Additional ones may be used if desired.
Phidgets Motor Control. This interface can be used to control motors, lights, and LEDs. It has 4 inputs for digital devices such as switches. It has 2 outputs to control two devices simultaneously. It has a USB connector to connect to a USB port in the computer, and it has a power supply input that can take from 5 to 9 volts DC. The power supply is used to supply electricity to the outputs. The interface itself gets its power from the computer. The following pictures illustrate the interface.
Two DC motors are supplied. The picture below shows them mounted on a chassis. If you look closely you can see through the clear plastic housing and find the motor and the plastic reduction gears.
There should be a ribbon cable with 4 wire strands, a USB cable and a 6 Volt DC power supply.
In addition a set of wheels are supplied for the motors, along with friction bands which need to be mounted on them.
The following examples of computer control employ the kit of parts described above.
This example uses the Phidgets Motor Control interface and one of the motors from the supplied kit. One of the wheels is mounted on the shaft and has a mark so that rotation is clearly visible. The motor is being controlled by a Visual Basic program which appears as an inset on the video clip. A person is manipulating the sliders in the program.
Video Computer Controlled Motor
This example uses the Phidgets Motor Control interface and two lights. In the first part, two incandescent bulbs are used. In the second part, two LEDs (light emitting diodes) are used. The same program is used in both cases. If you look closely you can see the pointer move as the person manipulates the screen controls to modify the light settings. As you can see, the two outputs can be controlled independently.
Video Computer Controlled Lighting
This example uses the Phidgets Motor Control interface and two of the DC motors with wheels mounted on them. The motors are mounted on a plastic chassis, and a roller is mounted at the other end. A post is used to hold the ribbon cable up higher and out of the way of the wheels
Video Computer Controlled Buggy
When you are ready, move to Your Turn