MyRoboPathOpen Robotics Lab
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ActuatorsQUICK REFERENCE

SG90 Servo

Three wires, a control pulse and a power supply that can handle motion.

Position controlMyRoboPath / Robotics field notes
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01Connections

Brown / black
Ground; join servo supply and MCU grounds.
Red
External regulated supply appropriate to the servo; original SG90 nominal operation is 4.8 V.
Orange / yellow
Control signal from the MCU. Confirm colors on your unit.

02Control pulses

Frame
Typically ~50 Hz: one pulse every ~20 ms.
Center
About 1500 us pulse width.
Travel
Start around 1000–2000 us; endpoints vary. Increase range only after checking mechanical limits.
Not motor PWM
Position depends on HIGH pulse width, not analogWrite duty alone.

03Practical setup

Power
Size the external supply for stall current; add local bulk capacitance.
Motion
Use small position steps; disconnect load during initial centering.
Arduino
Servo library: attach(signalPin); writeMicroseconds(1500).

Datasheets & further reading

Tower Pro SG90