* Add basic interrupt_disable+spinlock critical-section
* Update impl based on feedback from jannic
* Get rid of count variable, switch to AtomicU8 for lock state
* Remove interrupt::disable that isn't necessary for safety
* Rename variables, re-write most of the comments
* Add fences to ensure ordering
If GPIO23 is low, the power supply is in low-power mode. But it
generates some noise. If GPIO23 is high, the power supply is less
efficient, but it generates less noise too.
Start to address #186 (Safety requirement must be verbosely advertised to not be overlooked in future changes).
#177 (Mark PIO StateMachine, Rx and Tx as Send) added the Send trait to StateMachine, Tx and Rx, That documentation was expanded as suggested.
PIO, UninitStateMachine, Interrupt were marked Send before #177, added some documentation to those as well.
* Implement peripheral support for i2c and an advanced example for the pico board.
* Simplify i2c peripheral bootstrap and add a "free" function to allow switching modes.
* Set dependency to futures & nostd_async to specific version/revision.
* move enum & struct to the start of the file
* Add a bit of documentation to the pico_i2c_controller_peripheral demo.
* Migrate to pico_i2c_controller_peripheral to embassy & simplify the peripheral support
nostd_async is broken since last stable roll out.
The pico_i2c_controller_peripheral is being migrated to use embassy's executor.
The Controller Async API is now aligned with embassy's traits to facilitate integration.
The peripheral no longer require async to run and now appears as an event iterator.
Embassy's support relies on unstable features (generic_associated_types and type_alias_impl_traits)
and is therefore gated behind the `embassy-traits` feature flag.
* make futures & embassy optional for the pico board too
* Pin embassy to a specific rev.
* Impl embassy_traits::i2c::WriteIter & enable unlimited transfer size on i2c
* Applies comment suggestion from @9names for the advanced i2c example.
Co-authored-by: 9names <60134748+9names@users.noreply.github.com>
* use `I2C block` instead of `IP`.
* Fix formatting (unnecessary space at end of line)
* Enhance explanation for why `rd_req()` is not cleared in `Iterator::next`'s
implementation.
Co-authored-by: 9names <60134748+9names@users.noreply.github.com>
