16-Channel 12-Bit PWM/Servo Driver Shield (PCA9685, I2C)

Expanding far beyond a microcontroller's own PWM pins

This 16-channel PWM servo driver shield is built around an I2C-controlled chip that manages 16 free-running PWM outputs using only two pins from the host microcontroller, a significant expansion over the handful of PWM-capable pins most Arduino or similar boards offer natively. Each channel has 12-bit resolution, and PWM frequency is adjustable from 40Hz to 1000Hz, letting the module suit both standard hobby servos and LED dimming applications from the same board.

Because the module has 6 address-select pins, up to 62 of these boards can be chained together on the same I2C bus, giving a combined total of 992 outputs if a project genuinely needs that many channels, all still controlled through the same two I2C wires from a single microcontroller.

Power and connections

Logic signal voltage is compatible with 3V to 5V microcontrollers, while servo power input is separate and rated for a maximum of 6V, since servos typically draw far more current than a microcontroller's own 5V rail can safely supply. A terminal block with reverse-polarity protection accepts that separate servo power supply, and a green power-good LED indicator confirms the board is receiving power correctly.

Outputs are grouped in sets of 4 using 3-pin servo connectors, each with a 330-ohm series resistor for protection, and solder jumpers allow the address to be configured for chaining. Outputs can also be configured as push-pull or open-drain depending on what a specific project needs.

Who it suits

Robotics builders needing many servo channels for a hexapod leg, a robot arm with several joints, or any project running more servos or LEDs than a microcontroller's native PWM pins can handle will find this PCA9685-based shield a practical, well-documented expansion option.

Questions buyers ask

How many channels does it have?

16 per module, chainable up to 992 total across 62 modules.

How is it controlled?

Over I2C, using just two pins from the host microcontroller.

What is the maximum servo power input?

6V maximum, supplied separately from logic power.