Servo 9G — Python Reference

9G Micro Servo Motor

Wiring:

Servo Wire Colour	Connect To
Red	5V
Brown or Black	GND
Orange or Yellow (signal)	GPIO 13

{: .note } Servos can draw significant current when moving under load. If your ESP32 resets when the servo moves, power the servo from a separate 5V supply (keep GND connected to the ESP32's GND).

How PWM works for servos: Send a 50Hz signal. The pulse width (time the signal is HIGH) sets the angle: - 0.5ms pulse ≈ 0° - 1.5ms pulse ≈ 90° (centre) - 2.5ms pulse ≈ 180°

Code:

from machine import Pin, PWM
import time

servo = PWM(Pin(13), freq=50)

def set_angle(angle):
    """Move servo to angle (0–180 degrees)."""
    # Map 0–180° to duty cycle 40–115 (0–1023 range, 50Hz)
    # Adjust these values to calibrate your specific servo
    min_duty = 40
    max_duty = 115
    duty = int(min_duty + (angle / 180) * (max_duty - min_duty))
    servo.duty(duty)

# Move through positions
for angle in [0, 45, 90, 135, 180]:
    set_angle(angle)
    print(f"Angle: {angle}°")
    time.sleep(1)

servo.deinit()   # Release PWM when done

Calibrating your servo: If 0° and 180° aren't quite right, adjust min_duty and max_duty. Try values between 30–50 for min and 110–130 for max.

Simpler example

import time
from machine import Pin,PWM

servo1 = PWM(Pin((13)), freq=50)

# Move to 90 degrees
servo1.duty(int(30 + (90 / 180) * (125 - 30)))
time.sleep(1)

# Move to 0 degrees
servo1.duty(int(30 + (0 / 180) * (125 - 30)))
time.sleep(1)

# Move to 180 degrees
servo1.duty(int(30 + (180 / 180) * (125 - 30)))
time.sleep(1)