Fixes#2086
When the frequency of a `PWMOut` is change it re-sets the PWM's duty cycle as
well, since the registers have to be re-calculated based on the new frequency.
Unfortunately, `common_hal_pulseio_pwmout_get_duty_cycle`
will return a value very close to, but not exactly, the value passed to `common_hal_pulseio_pwmout_set_duty_cycle`. If the frequency is modified
without the calling code also re-setting the duty cycle then the duty cycle
will decay over time. This fixes that problem by tracking the unadjusted duty
cycle and re-setting the duty cycle to that value when the frequency is changed.
Its slimmed down by removing the qstr and bit packing TCC info.
The trinket m0 build actually grows by 20 bytes. The arduino zero
build shrinks by 188 bytes.
This evolves the API from 2.x (and breaks it). Playback devices are now
separate from the samples themselves. This allows for greater playback
flexibility. Two sample sources are audioio.RawSample and audioio.WaveFile.
They can both be mono or stereo. They can be output to audioio.AudioOut or
audiobusio.I2SOut.
Internally, the dma tracking has changed from a TC counting block transfers
to an interrupt generated by the block event sent to the EVSYS. This reduces
the overhead of each DMA transfer so multiple can occure without using up TCs.
Fixes#652. Fixes#522. Huge progress on #263
Jeff Epler
Dan Halbert
Thea Flowers
Thea Flowers
sommersoft
Scott Shawcroft
Scott Shawcroft
Roy Hooper