PCA9685 16-Channel 12-Bit PWM Servo Driver Module

The PCA9685 16-Channel Servo Driver Module generates 16 independent PWM signals through an I2C interface. Therefore, it provides an efficient solution for robots, animatronics, RC projects, and automation systems.

The onboard PCA9685 chip provides 12-bit PWM resolution with 4096 steps per channel. In addition, it generates the PWM signals internally. This feature reduces the processing load on the main microcontroller.

Key Features

• Controls up to 16 servos or PWM channels
• Provides 12-bit resolution with 4096 steps
• Communicates through the I2C interface
• Requires only SDA and SCL control lines
• Generates PWM signals independently
• Offers a programmable PWM frequency
• Includes six configurable address jumpers
• Supports multiple modules on one I2C bus
• Provides separate connections for logic and servo power
• Works with Arduino, ESP32, STM32, and Raspberry Pi

Technical Specifications

• Main IC: PCA9685
• Number of Channels: 16
• PWM Resolution: 12-Bit, 4096 Steps
• Communication Interface: I2C
• Default I2C Address: 0x40
• Logic Supply Voltage: 2.3–5.5V DC
• Input Logic Tolerance: Up to 5.5V
• Typical PWM Frequency Range: Approximately 24–1526Hz
• Common Servo Frequency: 50–60Hz
• Address Selection: A0 to A5 Solder Jumpers
• Maximum Modules: Up to 62 on one I2C bus
• Maximum Theoretical Channels: 992
• Servo Power: External supply according to servo requirements
• Operating Temperature of IC: -40°C to +85°C

Connections

• VCC: Logic supply for the PCA9685 chip
• GND: Common ground connection
• SDA: I2C data line
• SCL: I2C clock line
• OE: Active-low output enable
• V+: External power input for the servos
• PWM0–PWM15: Servo or PWM signal outputs

Each servo header normally provides:

• GND: Servo ground
• V+: External servo power
• PWM: Servo control signal

Powering the Servos

Use the VCC pin only to power the module’s logic circuit. Meanwhile, connect a separate regulated supply to the V+ terminal for the servos.

For example, many standard servos require a 5–6V supply. However, always check the voltage and current rating of your specific servo.

Connect the controller ground and servo-power ground together. Otherwise, the PWM signals may not work correctly.

Expanding the Number of Channels

The six address jumpers allow up to 62 PCA9685 devices on one I2C bus. As a result, one controller can theoretically address up to 992 PWM channels.

However, large systems require careful power distribution. Cable resistance, supply current, I2C capacitance, and electrical noise may limit the practical number of connected boards.

Applications

The PCA9685 module suits projects such as:

• Multi-servo robotic arms
• Hexapod and quadruped robots
• Animatronic systems
• RC vehicles and models
• Pan-and-tilt mechanisms
• Automated mechanical systems
• Low-current LED dimming
• Arduino and Raspberry Pi projects
• STEM and educational experiments

Important Notes

• Do not power several servos directly from the Arduino 5V pin.
• Use a separate supply with enough current for the connected servos.
• Connect all grounds together before operating the system.
• Large servos can draw high startup and stall currents.
• Add sufficient power-supply capacity for simultaneous servo movement.
• Check the polarity before connecting power to the V+ terminal.
• The PCA9685 controls servo signals but does not provide the servo operating current.
• Use external drivers for high-power LEDs and other high-current loads.
• All channels share the same PWM frequency, but each channel has an independent duty cycle.

Package Includes

• 1× PCA9685 16-Channel 12-Bit PWM Servo Driver Module