28123 Parallax Inc, 28123 Datasheet - Page 161

• Manufacturer Part Number: 28123
• Description: TEXT WHAT'S A MICROCONTROLLER
• Manufacturer: Parallax Inc
• Type: Programmingr

Specifications of 28123

• Style: Book
• Title: What's a Microcontroller?
• Contents: Whats a Microcontroller? Text
• Product: Microcontroller Accessories
• Core Processor: PIC16C57c
• Flash: 128 Bytes
• Operating Supply Voltage: 9 V
• Board Size: 31 mm x 16 mm
• Lead Free Status / RoHS Status: Not applicable / Not applicable

An example of a model airplane and its radio controller are shown in Figure 5-13. The
model airplane has servos to control all its flaps and the gas engine’s throttle settings.
These servos are controlled using the radio control (RC) unit in front of the plane. This
RC unit has potentiometers under a pair of joysticks that are used to control the servos
that in turn control the plane’s elevator and rudder flaps.
Potentiometer Controlled Servo Parts
(1) Potentiometer – 10 kΩ
(1) Resistor – 220 Ω (red-red-brown)
(1) Capacitor – 0.1 µF
(1) Parallax Standard Servo
(1) LED – any color
(2) Jumper wires
HomeWork Board users will also need:
(1) 3-pin male-male header
How the RC Unit Controls the Airplane: The potentiometers under the joysticks are
monitored by a circuit that converts the position of the joystick into control pulses for the
servo. These control pulses are then converted to radio signals and transmitted by the
handheld controller to a radio receiver in the model airplane. The radio receiver converts
these signals back to control pulses which then position the servos.
Figure 5-13
Model Airplane and
Radio Controller