Using Arduino to control a servo motor is a relatively simple and common task, mainly involving two aspects: hardware connection and programming. The following is a detailed step-by-step guide:
I. Hardware Connection
1. Servo Motor Pin Identification:
- Most servo motors have three wires: power wire (usually red or orange), ground wire (usually black or brown), and signal wire (usually yellow, white, or orange).
- The power wire is connected to the positive terminal of the power supply, the ground wire is connected to the negative terminal of the power supply, and the signal wire is connected to the digital pin of the Arduino.
2. Connecting to Arduino:
- Connect the power wire (red or orange) of the servo motor to the 5V pin of the Arduino.
- Connect the ground wire (black or brown) of the servo motor to the GND pin of the Arduino.
- Connect the signal wire (yellow, white, or orange) of the servo motor to any digital pin of the Arduino (such as D9).
3. Power Supply Considerations:
- For some high-torque servo motors, their current demand may exceed the current that the Arduino onboard 5V pin can provide (usually about 500mA). In this case, it is recommended to use an external power supply to power the servo motor, while ensuring that the ground wire is shared.
II. Programming control
1. Include the servo library:
- Arduino IDE provides the Servo library to simplify the control of servo motors. At the beginning of the code, include the Servo library:
//cpp
#include <Servo.h>
2. Define the servo object:
- Create a Servo object and associate it with the Arduino pin connected to the servo motor:
//cpp
Servo myservo; // Create a servo object
myservo.attach(9); // Connect the servo object to digital pin 9
3. Control the servo motor:
- Use the `write()` function to control the angle of the servo motor. The angle value is usually between 0 and 180 degrees, but the specific range depends on the specifications of the servo motor.
//cpp
void loop() {
myservo.write(90); // Rotate the servo motor to the 90 degree position
delay(1000); // Wait for one second
myservo.write(0); // Rotate the servo motor to the 0 degree position
delay(1000); // Wait for one second
// You can continue to add other angle controls as needed
}
III. Notes
- Pulse Width Modulation (PWM): Although users do not need to directly process PWM signals to control servo motors (because the Servo library has already encapsulated these operations), it is helpful to understand that PWM is the basic principle of controlling servo motors. Servo motors change their position by receiving PWM signals of different widths.
- Power Management: As mentioned earlier, for servo motors with high current requirements, an external power supply should be used, and ensure that the power supply is stable and the ground line is shared.
- Debugging: During the connection and programming process, if you encounter problems, you can use a multimeter to check the connection of the power and signal lines, as well as the voltage and current output of the Arduino pins.
With the above steps, you should be able to successfully control the servo motor with Arduino. If the servo motor does not work as expected, check that the connections are correct, the power supply is stable, and the code is correct.