Keyestudio ESP32 - 4. Test Code; 5. Test Result; 6. Code Explanation

ESP32 Starter Kit
4. Test Code
Add libraries to Arduino IDE first.
/*
keyestudio ESP32 Inventor Learning Kit
Project 12 Servo
http://www.keyestudio.com
*/
int servoPin = 4;//servo PIN
void setup() {
pinMode(servoPin, OUTPUT);//servo pin is set to output
}
void loop() {
for(int i = 0 ; i <= 180 ; i++) {
servopulse(servoPin, i);//Set the servo to rotate from 0° to 180°
delay(10);//delay 10ms
}
for(int i = 180 ; i >= 0 ; i--) {
servopulse(servoPin, i);//Set the servo to rotate from 180° to 0°
delay(10);//delay 10ms
}
}
void servopulse(int pin, int myangle) { //Impulse function
int pulsewidth = map(myangle, 0, 180, 500, 2500); //Map Angle to pulse width
for (int i = 0; i < 10; i++) { //Output a few more pulses
digitalWrite(pin, HIGH);//Set the servo interface level to high
delayMicroseconds(pulsewidth);//The number of microseconds of delayed pulse width␣
˓→value
digitalWrite(pin, LOW);//Lower the level of servo interface
}
}
5. Test Result
After connecting the wiring and uploading code, the servo starts to rotate from 0° to 180° and then reverse.
6. Code Explanation
void servopulse(int pin, int myangle) : To integrate the code together for easy use and management, the first parameter
is the pin number, the second parameter is the Angle of the servo.
map(myangle, 0, 180, 500, 2500); This is a mapping variable range function used to map the range of myangle variable
from 0-180 to 500-2500, so that we can get a value of 2500 when the servo is set to 180°, 500-2500 is the time that the
servo high level is maintained.
86 Chapter 8. Arduino Tutorial