SunFounder PCA9685 16 Channel 12 bit PWM Servo Driver for Arduino and Raspberry Pi
Quick take
The SunFounder PCA9685 board expands your project with 16 I2C-controlled, free-running PWM outputs (12-bit resolution), making it a practical add-on when your Arduino or Raspberry Pi runs out of PWM pins. It can also be used to chain multiple breakouts for larger channel counts. The main caveat is that you need to match the driver to your servo and load power setup, since power planning issues can cause instability.
Pros and cons
Pros
- Uses I2C control, so it reduces the number of pins your microcontroller needs.
- Free-running PWM outputs, so the signal generation runs on the driver after setup.
- 16 outputs with 12-bit resolution, suitable for servo-style control and PWM applications.
- 5V compliant logic, usable from 3.3V microcontrollers for mixed-voltage projects.
Cons
- Doesn’t eliminate the need for correct power distribution for servos and loads.
- Servo connectors are grouped, so physical stacking may be limited on standard 0.1-inch headers.
- Buyer-review evidence is mostly “it works,” with limited detail on long-term reliability.
What buyers think
Buyer feedback is generally positive about setup and usability, with multiple reports that it integrates smoothly with common maker platforms and runs multiple channels as expected. Users also highlight that they can use the board to control non-servo PWM loads (for example, LED brightness control) without needing extra PWM pins from the controller. Where concerns come up, the recurring theme is not a configuration mystery but power expectations, including a case where inadequate power guidance may have contributed to hardware failure. Overall, review evidence supports that the board is straightforward for typical I2C PWM expansion, but detailed long-term performance patterns are limited.
What this board is for
The PCA9685 is an I2C PWM driver built for projects that need more controllable channels than your microcontroller can provide. If you are planning a multi-servo robot, a small animatronic mechanism, or any setup where you want repeatable PWM outputs (like dimming LEDs through external drivers), this kind of board helps you offload PWM timing.
Key features that matter for real projects
I2C control with fewer microcontroller pins
Instead of using PWM-capable pins for every channel, the driver uses I2C to command the PCA9685. That typically simplifies wiring, especially once your channel count grows.
Free-running outputs
One of the most practical advantages is that the outputs run independently once configured. That means you avoid continuously “bit-banging” PWM signals from the MCU, freeing up processing time for other tasks.
12-bit resolution for finer positioning or PWM steps
Each output supports 12-bit resolution. For servo control, that translates to relatively fine-grained updates. The update rate mentioned for servo-style operation is around 60Hz, and the board’s resolution is described as about 4us per step at that update rate.
5V compliant logic
The board is designed to be 5V compliant, which is helpful when your microcontroller runs at 3.3V. This makes it easier to integrate into mixed-voltage Arduino or Raspberry Pi style setups.
Scales via chaining and compact output grouping
The product is designed so you can control multiple breakouts from the same I2C lines by chaining, increasing the total number of PWM outputs. Outputs are provided via 3-pin connectors grouped in fours, which is convenient for wiring multiple servos at once. Physical spacing can matter on 0.1-inch headers, since servo plugs are described as slightly wider than typical 0.1-inch pitch.
Wiring and power considerations (the part that can make or break the build)
A PWM/servo driver can generate the right timing, but servos and other loads still require correct power sizing and distribution. The board can handle up to 16 servo plugs per unit, but you need to ensure you’re providing the right voltage and enough current for your specific servo models and how many you move at the same time. If you are powering multiple servos, plan on separate, well-grounded power routing rather than relying on USB or a small regulator shared across everything.
Pros and cons for different buyer types
Best for
- Maker projects that need more PWM outputs than Arduino UNO-style boards provide.
- Multi-servo robots or mechanisms where you want stable timing without consuming MCU PWM pins.
- Raspberry Pi or microcontroller builds that use I2C and benefit from offloaded PWM generation.
- Anyone controlling PWM-driven accessories (with external drivers where needed) alongside their MCU.
Who should pause before buying
- If you already have enough PWM channels and don’t need I2C PWM expansion, it may be extra complexity.
- If your project’s power system is not planned (servo current, grounding, regulator capacity), you may run into instability or worse.
- If you require dense, stackable servo connector placement on tight 0.1-inch header layouts, connector spacing could affect how you mount wiring.
Verdict
The SunFounder PCA9685 16-channel 12-bit PWM servo driver is a solid choice when you want to expand servo or PWM control from Arduino or Raspberry Pi using I2C, especially because the board is designed to run outputs continuously after setup. For the best outcome, treat power and wiring as first-class parts of the design, since PWM timing alone does not solve servo load demands.
Want to compare current pricing before you commit? Buy on Amazon.
FAQ
Is the SunFounder PCA9685 16-channel driver only for servos?
No. It is commonly used for servos, but it is also a general-purpose I2C PWM generator. If you have a PWM-driven load that works with your external driver circuitry, you can use the outputs beyond servos.
Do I need to keep sending PWM signals from my Arduino or Raspberry Pi?
Not continuously. The outputs are described as free running, meaning the driver generates PWM after it receives the configuration over I2C.
Can this work with a 3.3V microcontroller?
The board is described as 5V compliant, and it is stated that it can be controlled from a 3.3V microcontroller for certain PWM use cases.
How many PWM channels does this board provide?
It provides 16 PWM outputs per breakout.
What’s the biggest potential drawback for servo projects?
Correct power planning. You need to ensure the servo supply and wiring can handle the current draw and that grounds are managed properly.
Does it support chaining to expand channel count?
Yes. The product is designed so you can chain multiple breakouts to control more PWM outputs from the same I2C setup.
Specifications
| Product Title | SunFounder PCA9685 16 Channel 12 bit PWM Servo Driver for Arduino and Raspberry Pi |
|---|---|
| Category | Electronics > Computers & Accessories > Computer Components > Desktop Barebones |
| Brand | SunFounder |
| Manufacturer | SunFounder |
| Model Name | PCA9685 |
| Model Number | miniLCD |
| Operating System | Linux, Windows 10 IoT Core |
| Item Weight | 0.02 Pounds |
| Processor Speed | 1 KHz |
| Connectivity Technology | I2C |
| Processor Brand | Nuvoton or STMicroelectronics |
| Compatible Devices | Devices with I2C communication support |
| Processor Count | 16 |
| Item Dimensions L x W x H | 5.2"L x 4.3"W x 0.8"H |
| Built-In Media | 1 x PCA9685 16-Channel 12-Bit PWM Servo Driver |
| UPC | 701715367203 |
| Mfr Part Number | miniLCD |
| Warranty Description | 1 Year Guarantee |
| CPU Speed | 1 KHz |
| Included Components | 1 x PCA9685 16-Channel 12-Bit PWM Servo Driver |
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