* using `stm32-hal`:
```rust
let _pwm_pin = gpioa.new_pin(PinNum::P0, PinMode::Alt(AltFn::Af1));

// Set up a PWM timer that will output to PA0, run at 2400Hz in edge-aligned mode,
// count up, with a 50% duty cycle.
let mut ec_timer = Timer::new_tim2(dp.TIM2, 2_400., &clock_cfg, &mut dp.RCC);
ec_timer.enable_pwm_output(Channel::One, OutputCompare::Pwm1, CountDir::Up, 0.5);
    ec_timer.enable();

// Setting auto reload preload allow changing frequency (period) while the timer is running.
ec_timer.set_auto_reload_preload(true);
ec_timer.set_freq(1_000.); // Change freq to 1000Hz.

// Or set PSC and ARR manually, eg to set freq, while preventing additional calculations.
ec_timer.set_auto_reload(100);
ec_timer.set_prescaler(100);
```