WIP New module: Esp32HardwarePwm

[pljakobs]

Summary

This PR adds Esp32HardwarePwm, a comprehensive C++ wrapper for the ESP32 LEDC PWM peripheral, to Arch/Esp32/Components

Motivation

The ESP32 LEDC hardware is significantly more capable than the ESP8266 PWM — it supports up to 20-bit resolution, frequencies up to 40 MHz, hardware-accelerated linear fading, and phase shifting across multiple independent timer+channel groups. The pre-existing HardwarePWM API surface does not expose these capabilities on Esp32. This component provides a native Esp32-specific driver that takes full advantage of the hardware.

Features

• Multiple independent instances — each with its own timer configuration (frequency, resolution, speed mode, timer index); multiple instances coexist by using non-overlapping channel ranges
• Flexible duty cycle control — both channel-indexed and legacy pin-indexed analogWrite API; configurable 1–20-bit resolution
• Phase shifting — OFF, AUTO (evenly distributed), or MANUAL (per-pin hpoint values) to reduce inrush current spikes and EMI
• Spread spectrum — optional frequency dithering around the base frequency for EMI reduction
• Hardware fade — hardware-accelerated linear transitions via the LEDC fade engine; ISR installed lazily on first use
• Per-channel fade queue — chain multiple fades per channel without application polling:
  • FIFO mode: plays entries once in order, auto-starts on first enqueue, fires onQueueEmpty callback when drained
    CYCLIC mode: loops the entry set endlessly, fires onCyclicWrap each loop, requires explicit startQueue() after seeding
  • Per-channel configurable queue depth (default 10, uint16_t); runtime resize while queue is empty
  • Three callback slots: onFadeDone, onQueueEmpty, onCyclicWrap — dispatched via System.queueCallback (task context, ISR-safe)

[what-the-diff]

PR Summary

• Introduction of "Esp32HardwarePwm" Submodule
  A new module named "Esp32HardwarePwm" has been added to further enhance the project functionalities. This new component will be incorporated from another repository as a submodule.

• Establishment of "Esp32HardwarePwm" Submodule Directory
  This refers to the creation of a dedicated space or directory for the "Esp32HardwarePwm" submodule. It helps to organize different modules effectively. This specific initialization is linked to a particular update or change noted as a "commit".

[pljakobs]

This has become pretty massive but it's also now very functionally complete.
It covers the minimal functionality of configuring a set of channels for PWM and sentting both percentage and absolute value.
It also allows to leverage the Esp32 ledc's functionality to set a variety of PWM frequencies and bit widths (tested to 64kHz and 8Bit).
Additional features:

• automatic or manual hpoint setting to allow phase shifting channels
• spread spectrum to reduce the peak spectral load and "smear" it out
• CIE 1931 curve to allow for linear perception brightness fading
• hardware fade support
• queued fade support with Sming native callbacks
• experimental timing correction support with companion application to calculate SOC specific timing parameters

[pljakobs]

the build errors are changed function names int he sample app. I'll fix these in ab it.