SG90 Servo

• Brown / Black: GND
• Red: +5 V to 6 V
• Orange / Yellow: Signal (PWM)

Note: Wire colors vary by brand; check your cable. Always share ground with the controller.

External 5–6 V supply to servo power, signal from controller pin, grounds tied together.

Basic Sweep

#include <Servo.h>
Servo s;
void setup(){ s.attach(9); }      // signal on D9
void loop(){
  for(int a=0;a<=180;a+=2){ s.write(a); delay(10); }
  for(int a=180;a>=0;a-=2){ s.write(a); delay(10); }
}

Microsecond Control (fine trim)

#include <Servo.h>
Servo s;
void setup(){ s.attach(9); }  // D9
void loop(){
  // Typical SG90 range ≈ 500–2500 µs (may vary; start 700–2300 µs)
  for(int us=700; us<=2300; us+=20){ s.writeMicroseconds(us); delay(15); }
  for(int us=2300; us>=700; us-=20){ s.writeMicroseconds(us); delay(15); }
}

Tip: If the servo buzzes at the ends, reduce the travel (e.g., 10–170° or 800–2200 µs).

For stable pulses, use a library that generates accurate servo timing (e.g., pigpio).

pigpio: Servo pulses

# sudo apt install pigpio python3-pigpio
# sudo systemctl start pigpiod
import time, pigpio
PIN = 18  # BCM pin with hardware PWM
pi = pigpio.pi()
pi.set_servo_pulsewidth(PIN, 1500)  # center (~1.5 ms)
time.sleep(1)
for us in range(800, 2301, 50):
    pi.set_servo_pulsewidth(PIN, us); time.sleep(0.03)
for us in range(2300, 799, -50):
    pi.set_servo_pulsewidth(PIN, us); time.sleep(0.03)
pi.set_servo_pulsewidth(PIN, 0)     # stop pulses
pi.stop()

RPi.GPIO PWM (simple)

# sudo apt install python3-rpi.gpio
import time, RPi.GPIO as GPIO
PIN = 18  # BCM
GPIO.setmode(GPIO.BCM)
GPIO.setup(PIN, GPIO.OUT)
p = GPIO.PWM(PIN, 50)  # 50 Hz
p.start(0)
def write_us(us):
    duty = (us / 20000.0) * 100.0  # 20 ms frame
    p.ChangeDutyCycle(duty)
try:
    for us in range(800, 2301, 50): write_us(us); time.sleep(0.03)
    for us in range(2300, 799, -50): write_us(us); time.sleep(0.03)
finally:
    p.stop(); GPIO.cleanup()

• Power: Use a separate 5–6 V supply; don’t draw servo current from the Pi.
• Grounds: Tie servo supply GND to Pi GND.

ESP32/ESP8266: Drive SG90 with 50 Hz pulses. Use a separate 5–6 V rail and common ground. ESP32 has ledc PWM; ESP8266 can use Servo or software PWM.

ESP32 (Arduino core): LEDC servo sweep

#include <Arduino.h>
const int SERVO_PIN = 25;     // any PWM-capable pin
const int CH = 0;
void setup(){
  ledcSetup(CH, 50, 16);      // 50 Hz, 16-bit
  ledcAttachPin(SERVO_PIN, CH);
}
void writeUS(int us){         // map µs to 16-bit duty
  // 50 Hz frame = 20,000 µs -> duty = us/20000 * 65535
  uint32_t duty = (uint32_t)((us * 65535UL) / 20000UL);
  ledcWrite(CH, duty);
}
void loop(){
  for(int us=800; us<=2300; us+=20){ writeUS(us); delay(15); }
  for(int us=2300; us>=800; us-=20){ writeUS(us); delay(15); }
}

ESP8266 (Arduino core): Servo library

#include <Arduino.h>
#include <Servo.h>
Servo s;
void setup(){ s.attach(D5); }  // choose a suitable pin
void loop(){
  for(int a=10;a<=170;a+=2){ s.write(a); delay(10); }
  for(int a=170;a>=10;a-=2){ s.write(a); delay(10); }
}

ESP-IDF (C): LEDC 50 Hz helper

// Minimal ESP-IDF example (component: driver/ledc)
#include "driver/ledc.h"
#include "esp_err.h"
#define SERVO_PIN 25
static void servo_init(){
  ledc_timer_config_t t = {
    .speed_mode=LEDC_LOW_SPEED_MODE, .timer_num=LEDC_TIMER_0,
    .duty_resolution=LEDC_TIMER_16_BIT, .freq_hz=50, .clk_cfg=LEDC_AUTO_CLK
  };
  ledc_timer_config(&t);
  ledc_channel_config_t c = {
    .gpio_num=SERVO_PIN, .speed_mode=LEDC_LOW_SPEED_MODE, .channel=LEDC_CHANNEL_0,
    .timer_sel=LEDC_TIMER_0, .duty=0, .hpoint=0
  };
  ledc_channel_config(&c);
}
static void servo_write_us(uint16_t us){
  uint32_t duty = (us * ((1<<16)-1)) / 20000;  // 16-bit
  ledc_set_duty(LEDC_LOW_SPEED_MODE, LEDC_CHANNEL_0, duty);
  ledc_update_duty(LEDC_LOW_SPEED_MODE, LEDC_CHANNEL_0);
}
// call servo_init() once, then sweep 800..2300 µs in your task

See Espressif docs in Resources → Espressif for full ledc and examples.

No drivers are needed for the servo itself. If you’re using a USB-serial bridge for control or logging:

• CH341 Driver (GitHub)

Arduino

• Arduino Project Hub
• Arduino Playground
• Arduino IDE Download
• Install Arduino Libraries

Raspberry Pi

• Raspberry Pi Projects
• GPIO Zero Docs
• Raspberry Pi Docs
• Raspberry Pi Software
• Pi Getting Started

Espressif

• ESP-IDF Programming Guide (Official)
• Espressif Technical Docs / Datasheets / Design Guidelines
• ESP-IDF GitHub Repository
• Arduino Core for ESP32 (GitHub)
• PlatformIO + ESP-IDF

Drivers / Other

• CH341 Driver (GitHub)

Note: Specs vary slightly by manufacturer. Always test travel limits gently to avoid binding.

Important Notice For educational, prototype, experimental, laboratory and R&D use only. (non-RoHS).

WEEE

Not subject to WEEE marking; obligations apply to final equipment.

Manufacturer

Little Muffins Things Limited
166 River Heights, 90 High Street
London E15 2GQ
littlemuffinsthings.com

EU Responsible Person

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hello@eucompliancepartner.com