Constant dma_gpio::pi::DEFAULT_PWM_DIVISOR

pub const DEFAULT_PWM_DIVISOR: usize

= 500. Default value for pwm div.

PWM runs at the frequency of 500 MHz. So setting this as 500 will give us 500MHz/500 = 1 MHz. You can change this configuration with [BoardBuilder::divide_pwm(mut self, divisor)](struct.BoardBuilder.html#method.divide_pwm: usize)