How to control duty cycle precision?

[pixpop]

The RP2040 allows 16 bit precision for PWM.

How do I control the PWM precision with this library? Specifically, I need to get 16 bit duty cycle precision. Can you explain? The API calls seem to take a float for duty cycle, but no way to specify the precision.

[khoih-prog]

Currently, the Arduino rp2040-related mbed cores (mbed_nano, mbed_rp2040) don't provide a way to specify the resolution, and I believe, as common sense, they will use the best 16-bit resolution.

The DC is using float to provide the better precision.

You can reduce, IMO not what you'd like, the precision by using fake mapping such as analogWrite() by

void analogWrite(PinName pin, int val)
{
  pin_size_t idx = PinNameToIndex(pin);
  if (idx != NOT_A_PIN) {
    analogWrite(idx, val);
  } else {
    mbed::PwmOut* pwm = new mbed::PwmOut(pin);
    pwm->period_ms(2); //500Hz
    float percent = (float)val/(float)((1 << write_resolution)-1);
    pwm->write(percent);
  }
}

[pixpop]

Okay, understood. It's only a few lines of code for the pico sdk, so I'll just use that instead.