PCA9685 16 Channel PWM Servo Driver Module

The PCA9685 16-Channel PWM Servo Driver Module is an integrated circuit (IC) that allows a microcontroller to control up to 16 PWM (pulse width modulation) outputs using only two I²C communication pins. This module is ideal for projects that require a large number of PWM outputs, such as robotics with many servo motors or LED lighting systems.

Features:

• 16-channel PWM control: The module provides 16 independent PWM outputs, each with a 12-bit resolution (4096 programmable steps), allowing for precise control.
• I²C communication: It uses the I²C protocol for communication, reducing the number of control pins needed on your microcontroller.
• Built-in clock: The PCA9685 has an onboard clock, which means the microcontroller doesn't need to send continuous signals to maintain the PWM output, freeing it up for other tasks.
• Adjustable frequency: The PWM frequency is adjustable from 24 Hz to 1526 Hz. For servos, a standard frequency is 50–60 Hz.
• Daisy-chainable: Multiple modules can be linked together on the same I²C bus. With its 6 address selection pins, up to 62 modules can be connected, providing a total of 992 outputs.
   
• 5V compliant: It can be controlled by both 3.3V and 5V microcontrollers. 

Pinout

The module's pin configuration is crucial for proper setup and includes power, I²C, address, and output pins. 

Power pins 

• VCC: Powers the module's internal logic. Connect to your microcontroller's power rail (3.3V to 5V).
• GND: Common ground for both the module and the external power supply for the servos.
• V+: External power input for the connected devices (e.g., servos or LEDs). Typically 5V to 6V for standard servos. 

I²C control pins 

• SDA: I²C data line.
• SCL: I²C clock line.
• OE (Output Enable): An optional pin that, when pulled high, disables all outputs. It is active low and is often left unconnected. 

Address selection pins 

• A0–A5: Solder jumpers used to set the unique I²C address for the module. This is necessary for daisy-chaining multiple modules. The default I²C address is 0x40 when none of the jumpers are soldered. 

Output channels

• Outputs 0–15: Each channel has a three-pin header (V+, GND, and PWM) for connecting servos or LEDs. 

How to use with a microcontroller 

Wiring 

1. Connect the module's VCC to your microcontroller's 5V or 3.3V pin.
2. Connect the module's GND to your microcontroller's ground.
3. Connect the module's SDA and SCL pins to your microcontroller's corresponding I²C pins (e.g., Arduino Uno A4/A5, Raspberry Pi GPIO2/3).
4. Connect an external power supply to the module's V+ and GND terminals. This is important when powering multiple servos, as the microcontroller cannot supply enough current.
5. Connect the servo motor signal wires to the desired PWM outputs (0–15) on the module.

Software (Arduino)

1. Install the library: Using the Arduino IDE Library Manager, install the "Adafruit PWM Servo Driver Library".
2. Include the library: At the top of your sketch, include Adafruit_PWMServoDriver.h.
3. Initialize: Create a Adafruit_PWMServoDriver object and begin communication with pwm.begin().
4. Set frequency: For servos, set the PWM frequency to 50 or 60 Hz using pwm.setPWMFreq(50).
5. Set servo position: Use the pwm.setPWM(channel, on_time, off_time) function to control the servo. The on_time and off_time values control the pulse length and, consequently, the servo's angle.

Software (Raspberry Pi) 

1. Enable I²C: First, enable the I²C interface in your Raspberry Pi's configuration.
2. Install library: Use pip to install the required library: pip3 install adafruit-circuitpython-pca9685.
3. Code in Python: Use the board, busio, and adafruit_pca9685 libraries to write your program. Set the frequency and pulse length to control your servos or LEDs.

Package Included:

• 1 x PCA9685 – 16 Channel 12-Bit PWM Servo Motor Driver I2C Module For Arduino