107 lines
3.9 KiB
C++
107 lines
3.9 KiB
C++
/*
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* ESP32 Servo Example Using Arduino ESP32 Servo Library
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* John K. Bennett
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* March, 2017
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*
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* This sketch uses the Arduino ESP32 Servo Library to sweep 4 servos in sequence.
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*
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* Different servos require different pulse widths to vary servo angle, but the range is
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* an approximately 500-2500 microsecond pulse every 20ms (50Hz). In general, hobbyist servos
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* sweep 180 degrees, so the lowest number in the published range for a particular servo
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* represents an angle of 0 degrees, the middle of the range represents 90 degrees, and the top
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* of the range represents 180 degrees. So for example, if the range is 1000us to 2000us,
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* 1000us would equal an angle of 0, 1500us would equal 90 degrees, and 2000us would equal 1800
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* degrees.
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*
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* Circuit:
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* Servo motors have three wires: power, ground, and signal. The power wire is typically red,
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* the ground wire is typically black or brown, and the signal wire is typically yellow,
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* orange or white. Since the ESP32 can supply limited current at only 3.3V, and servos draw
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* considerable power, we will connect servo power to the VBat pin of the ESP32 (located
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* near the USB connector). THIS IS ONLY APPROPRIATE FOR SMALL SERVOS.
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*
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* We could also connect servo power to a separate external
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* power source (as long as we connect all of the grounds (ESP32, servo, and external power).
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* In this example, we just connect ESP32 ground to servo ground. The servo signal pins
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* connect to any available GPIO pins on the ESP32 (in this example, we use pins
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* 22, 19, 23, & 18).
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*
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* In this example, we assume four Tower Pro SG90 small servos.
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* The published min and max for this servo are 500 and 2400, respectively.
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* These values actually drive the servos a little past 0 and 180, so
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* if you are particular, adjust the min and max values to match your needs.
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* Experimentally, 550 and 2350 are pretty close to 0 and 180.
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*/
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#include <ESP32Servo.h>
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// create four servo objects
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Servo servo1;
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Servo servo2;
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Servo servo3;
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Servo servo4;
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// Published values for SG90 servos; adjust if needed
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int minUs = 500;
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int maxUs = 2400;
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// These are all GPIO pins on the ESP32
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// Recommended pins include 2,4,12-19,21-23,25-27,32-33
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int servo1Pin = 18;
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int servo2Pin = 19;
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int servo3Pin = 22;
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int servo4Pin = 23;
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int pos = 0; // position in degrees
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void setup()
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{
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servo1.attach(servo1Pin, minUs, maxUs);
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servo2.attach(servo2Pin, minUs, maxUs);
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servo3.attach(servo3Pin, minUs, maxUs);
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servo4.attach(servo4Pin, minUs, maxUs);
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}
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void loop() {
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for (pos = 0; pos <= 180; pos += 1) { // sweep from 0 degrees to 180 degrees
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// in steps of 1 degree
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servo1.write(pos);
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delay(20); // waits 20ms for the servo to reach the position
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}
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for (pos = 180; pos >= 0; pos -= 1) { // sweep from 180 degrees to 0 degrees
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servo1.write(pos);
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delay(20);
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}
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for (pos = 0; pos <= 180; pos += 1) { // sweep from 0 degrees to 180 degrees
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// in steps of 1 degree
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servo2.write(pos);
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delay(20); // waits 20ms for the servo to reach the position
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}
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for (pos = 180; pos >= 0; pos -= 1) { // sweep from 180 degrees to 0 degrees
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servo2.write(pos);
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delay(20);
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}
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for (pos = 0; pos <= 180; pos += 1) { // sweep from 0 degrees to 180 degrees
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// in steps of 1 degree
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servo3.write(pos);
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delay(20); // waits 20ms for the servo to reach the position
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}
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for (pos = 180; pos >= 0; pos -= 1) { // sweep from 180 degrees to 0 degrees
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servo3.write(pos);
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delay(20);
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}
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for (pos = 0; pos <= 180; pos += 1) { // sweep from 0 degrees to 180 degrees
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// in steps of 1 degree
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servo4.write(pos);
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delay(20); // waits 20ms for the servo to reach the position
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}
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for (pos = 180; pos >= 0; pos -= 1) { // sweep from 180 degrees to 0 degrees
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servo4.write(pos);
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delay(20);
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}
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}
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