Interfacing a Servo to the Atmega 128
Interface a servo to the Atmega 128 and control its movement under program control Use a 74HC4017 decade counter as multiplexer and explain how it could be used to control up to five servos
Components
Qty. Item
1 Atmel Atmega 128 microcontroller with STK 500 and STK 501 interface boards,
1 Serial port cable
1 Futaba FP-S148 servo
1 74HC4017 decade counter chip
Introduction
In this lab you will explore the workings of a radio control (R/C) servo and how the Atmega 128 can be used to control one.
An R/C servo consists of a dc motor, gear train, potentiometer, and some control circuitry all mounted compactly in a case. R/C servos are commonly used in radio-controlled cars, airplanes, and boats to provide limited rotational motion to steer, move control surfaces, etc.
R/C servos are attractive for educational use in mechatronics, because they are relatively inexpensive (about $12-$20), they can put out reasonably high torque (about 42 oz/in for standard sizes), they can easily be modified to produce continuous shaft rotation at relatively slow speeds, and they can easily be controlled by a microcontroller. There are three wires, white, red, and black on the servo leading from a 3-pin female connector to the case. These carry the control signal, power, and ground return respectively.
Interface a servo to the Atmega 128 and control its movement under program control Use a 74HC4017 decade counter as multiplexer and explain how it could be used to control up to five servos
Components
Qty. Item
1 Atmel Atmega 128 microcontroller with STK 500 and STK 501 interface boards,
1 Serial port cable
1 Futaba FP-S148 servo
1 74HC4017 decade counter chip
Introduction
In this lab you will explore the workings of a radio control (R/C) servo and how the Atmega 128 can be used to control one.
An R/C servo consists of a dc motor, gear train, potentiometer, and some control circuitry all mounted compactly in a case. R/C servos are commonly used in radio-controlled cars, airplanes, and boats to provide limited rotational motion to steer, move control surfaces, etc.
R/C servos are attractive for educational use in mechatronics, because they are relatively inexpensive (about $12-$20), they can put out reasonably high torque (about 42 oz/in for standard sizes), they can easily be modified to produce continuous shaft rotation at relatively slow speeds, and they can easily be controlled by a microcontroller. There are three wires, white, red, and black on the servo leading from a 3-pin female connector to the case. These carry the control signal, power, and ground return respectively.