Function adafruit_motorkit::init_pwm

pub fn init_pwm(i2c: Option<I2cdev>) -> Result<Pca9685<I2cdev>, MotorError>

Initializes the PWM to control the Motor HAT. This makes a few assumptions:

• Assumes only one Motor HAT as 0x96.
• Assumes only a pre-scale of 4 so the HAT is running at ~1600 Hz.

If no I2C bus is provided to the function, it will attempt to connect to /dev/i2c-1 which will work in most cases.