Servo
library
for
controlling servo motors
Functions
Description
Attach the Servo variable to a pin.
Note that in Arduino 0016 and earlier, the
Servo library supports only servos on only two pins: 9 and 10.
Syntax
servo
.attach(pin)
servo
.attach(pin, min, max)
Parameters
servo: a variable of
type Servo
pin: the number of the
pin that the servo is attached to
min (optional): the
pulse width, in microseconds, corresponding to the minimum (0-degree)
angle on the servo (defaults to 544)
max (optional): the
pulse width, in microseconds, corresponding to the maximum (180-degree)
angle on the servo (defaults to 2400)
Example
#include <Servo.h>
Servo myservo;
void setup()
{
myservo.attach(9);
}
void loop() {}
Description
Writes a value to the servo, controlling
the shaft accordingly. On a standard
servo, this will set the angle of the shaft (in degrees), moving the
shaft to that orientation. On a
continuous rotation servo, this will set the speed of the servo (with 0
being full-speed in one direction, 180 being full speed in the other,
and a value near 90 being no movement).
Syntax
servo
.write(angle)
Parameters
servo: a variable of
type Servo
angle: the value to
write to the servo, from 0 to 180
Example
#include <Servo.h>
Servo myservo;
void setup()
{
myservo.attach(9);
myservo.write(90); // set servo to mid-point
}
void loop() {}
Description
Writes a value in
microseconds (uS) to the servo, controlling the shaft accordingly.
On a standard servo, this will set the angle
of the shaft. On standard servos a
parameter value of 1000 is fully counter-clockwise, 2000 is fully
clockwise, and 1500 is in the middle.
Note that some
manufactures do not follow this standard very closely so that servos
often respond to values between 700 and 2300. Feel free to increase
these endpoints until the servo no longer continues to increase its
range. Note however that attempting to
drive a servo past its endpoints (often indicated by a growling sound)
is a high-current state, and should be avoided.
Continuous-rotation
servos will respond to the writeMicrosecond function in an analogous
manner to the
write function.
Syntax
servo
.writeMicroseconds(uS)
Parameters
servo: a variable of
type Servo
uS: the value of the
parameter in microseconds ( int
)
Example
#include <Servo.h>
Servo myservo;
void setup()
{
myservo.attach(9);
myservo.writeMicroseconds(1500); // set servo to mid-point
}
void loop() {}
Description
Read the current angle
of the servo (the value passed to the last call to write()).
Syntax
servo .read()
Parameters
servo: a variable of
type Servo
Returns
The angle of the
servo, from 0 to 180 degrees.
Description
Check whether the
Servo variable is attached to a pin.
Syntax
servo
.attached()
Parameters
servo: a variable of
type Servo
Returns
true if the servo is
attached to pin; false otherwise.
Description
Detach the Servo
variable from its pin. If all Servo
variables are detached, then pins 9 and 10 can be used for PWM output
with analogWrite().
Syntax
servo
.detach()
Parameters
servo: a variable of
type Servo
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