455: simple_playback api from nrf sdk r=Dirbaio a=jacobrosenthal
Port of the nrf_drv_pwm_simple_playback call from the nordic sdk that allows you to set up a sequence to play across leds with no interaction necessary using the 'shorts' registers to trigger looping sequences
Co-authored-by: Jacob Rosenthal <jacobrosenthal@gmail.com>
Rustflags apply to ALL the crates in the graph, while we only need
them for the toplevel crate which is the only one getting linked.
Rustflags are not equal for all crates, this caused cargo to re-build the
same dependency crate multiple times uselessly. After this change, deps
are reused more, making builds faster.
Note that this only applies when sharing the target/ dir for multiple crates
in the repo which is not the default.
- Removed ConfigurableChannel and added capacity numbers to the channels
- Replaced the PPI api with a new one using the DPPI terminology (publish & subscribe)
- Updated all tasks and event registers for DPPI
Implements continuous sampling for the nRF SAADC and also renames `OneShot` to `Saadc`. The one-shot behaviour is retained with the `sample` method and a new `run_sampler` method is provided for efficiently (i.e. zero copying) sampler processing. A double buffer is used for continuously sampling, which wlll be swapped once sampling has taken place.
A sample frequency is provided and will set the internal timer of the SAADC when there is just the one channel being sampled. Otherwise, PPI will be used to hook up the TIMER peripheral to drive the sampling task.
One-shot mode now permits the sampling of differential pins, and the sampling of multiple pins simultaneously.
A new ChannelConfig structure has been introduced so that multiple channels can be configured individually. Further, the `sample` method now accepts a buffer into which samples are written.
Along the way, I've reset some default configuration to align with Nordic's settings in their nrfx saadc driver. Specifically, the channel gain defaults to 6 (from 4) and the time defaults to 10us (from 20us).
