Ingredient
Servo motor
Also known as: RC servo, hobby servo, MG996R, SG90
Position-controllable rotary actuator with built-in feedback — small geared motor + position-encoder + driver in a single package. Receives a PWM pulse-width signal (1.0–2.0 ms typical) and rotates to a corresponding angle (0°–180° standard, or 360° continuous-rotation variants). The simplest actuator in the toolkit. SG90 (~$3, 1.8 kg·cm torque, plastic gears) for light tasks; MG996R (~$8, 11 kg·cm torque, metal gears) for medium load; industrial servos for heavy work. Standard 3-wire interface: V+, GND, signal.
Inputs / outputs
- Power: 4.8–6V typical (separate supply from MCU; servos draw current spikes that crash logic rails)
- Signal: PWM, 50 Hz frame rate, 1.0–2.0 ms pulse width = 0°–180°
- Torque: SG90 ~1.8 kg·cm; MG996R ~11 kg·cm; industrial up to 100+ kg·cm
- Speed: ~0.1–0.2 sec per 60° typical
Solves / unlocks
- Vent / damper actuation in greenhouses
- Coop / barn door opening
- Drip-line valve operation
- Light-controlled plant-rotation platforms
- Robotic arm joints (small scale; [[farmbot-genesis|FarmBot]] uses steppers for precision but servos for simpler accessories)
- Camera pan-tilt mounts
Constraints
- Power-supply isolation matters — servos pull amps; share rails with a logic board and you’ll reset the MCU.
- Position holding burns current — some applications want a [[stepper-motor|stepper]] or a worm-drive instead.
- Plastic gears strip under repeated heavy load — go metal-gear for anything load-bearing.
- Continuous-rotation servos are speed-controlled, not position-controlled — different application class.
Source
- Reference: https://www.adafruit.com/product/169 (SG90)
- PWM HAT for RPi: https://www.adafruit.com/product/2327
See also
Auto-generated from this entry’s typed relations: frontmatter, grouped by relation type so the editorial signal isn’t flattened.
- Member of: [[ingredient]]
- Combines with: [[arduino-uno]] · [[esp32]] · [[raspberry-pi]] · [[ros2]]
What links here, and how
Inbound connections from across the wiki, grouped by lens and by relationship. These appear automatically — every entity page declares what it links to, and that data populates here on the targets.
Practical
combines with
- Arduino Uno Servo.h library; light-actuated mechanical work
- ROS 2 ROS2 servo controllers expose joint-position interfaces for arm-style robots
contains
- Farm-tech toolkit actuator / position-controlled rotary actuator
combines
- Recipe: closed-loop greenhouse climate controller vent-window actuator; or use linear actuators for heavy roof vents
parallels
- Stepper motor stepper for precision and high-torque holding; servo for simpler position-and-go work
5 inbound links · 5 outbound