Arduino Uno Quick Start Manual page 244

void loop() {
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const unsigned int
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char degrees[MAX_ANGLE + 1];
20
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if (Serial.available()) {
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int i = 0;
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while (Serial.available() && i < MAX_ANGLE + 1) {
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const char c = Serial.read();
25
if (c != -1 && c != '\n')
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degrees[i++] = c;
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delay(SERIAL_DELAY);
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}
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degrees[i] = 0;
30
int value = atoi(degrees);
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if (value == 0)
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value = 1;
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Serial.print(value);
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Serial.println("
35
servo.write(value);
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delay(MOTOR_DELAY);
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}
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}
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We include the Servo library, and in line 8, we define a new
the setup function, we initialize the serial port, and we
to the pin we have defined in
so the servo motor has enough time to process our command. Then we call
write to move the servo back to 1 degree. We could also move it back to 0
degrees, but some of the servos I ve worked with make some annoying noise
in this position.
The main purpose of the
serial port. These values are in a range from 0 to 180, and we read them as
ASCII values. So, we need a string that can contain up to four characters.
(Remember, strings are null-terminated in C.) That s why we declare the
string with a length of four in line 20.
Then we wait for new data to arrive at the serial port and read it character
by character until no more data is available or until we have read enough.
We terminate the string with a zero byte and print the value we ve read to the
serial port. Finally, we convert the string into an integer value using
pass it to the write
for the servo to do its job.
Compile and upload the sketch, then open the serial monitor. After the servo
has initialized, send some degree values, such as 45, 180, or 10. See how the
MAX_ANGLE = 3;
degrees.");
MOTOR_PIN . After that, we wait for 15 milliseconds
loop function is to read new degree values from the
method of the Servo object in line 36. Then we wait again
www.it-ebooks.info
First Steps with a Servo Motor
Servo object. In
attach the Servo object
degrees
atoi and
229
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