.. _changelog_v4_0_2:

v4.0.2
======

v4.0.2 introduces the initial **RP2040** port (Raspberry Pi Pico / Arduino
Nano RP2040 Connect board files), PixArt PAJ6100 and MT9M114 sensor support, a
PDM audio filter library, and :mod:`sensor` improvements. STM32 ADC and the
image-transfer path changed — read the breaking changes below.

.. contents:: On this page
   :local:
   :depth: 1

Highlights
----------

- **Initial RP2040 port** — Raspberry Pi Pico / Arduino Nano RP2040 Connect
  board files.
- **New sensors** — PixArt PAJ6100 and a working MT9M114 driver.
- **PDM audio filter library**; :func:`sensor.set_framerate` works for any FPS.
- **Breaking:** the STM32 ADC driver was aligned with upstream and full MDMA
  image-transfer offload was enabled — see the breaking changes.

New features
------------

- **RP2040 port** — added the RP2040 port with Raspberry Pi Pico and Arduino
  Nano RP2040 Connect board files (initial bring-up; WiFi/Bluetooth land in
  v4.1.0).
- **PixArt PAJ6100** camera sensor support and a working MT9M114 driver.
- **PDM audio filter library** added to the audio path.
- **Sensor** — :func:`sensor.set_framerate` now works for any FPS, a method to
  read the actual XCLK frequency was added, additional sensor resolutions are
  supported, and a ``disable_full_flush`` framebuffer option was added.

Other changes and improvements
------------------------------

- Snapshot error messages were made clearer; Ethernet updates and a
  low-power mode were added (Portenta).

Bug fixes
---------

- Fixed the :class:`pyb.Servo` timer channel state, the LSM6Dx IMU driver, the
  STM32 H7 ``dma_nohal_init``, and a missing framesize init check.

Hardware and board support
--------------------------

- **Raspberry Pi Pico / Arduino Nano RP2040 Connect** — initial board
  files.
- **PixArt PAJ6100** and **MT9M114** camera sensors.

Breaking API changes
--------------------

User-visible API breaks between v4.0.1 and v4.0.2.

Both breaking changes are *behavior* changes (same API, different results) —
re-check affected scripts. Each commit hash links to its diff on GitHub.

.. _v4_0_2_behavior:

STM32 ADC alignment and full MDMA offload *(behavior)*
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

The STM32 ADC driver was aligned with the upstream MicroPython
implementation, so :class:`machine.ADC` behavior/readings may differ slightly from
previous releases. Separately, full MDMA offload of image transfers was
enabled, which speeds up capture but changes the transfer path and timing.
Re-check ADC-dependent code and timing-sensitive captures.

*Commits:* `661169f85 <https://github.com/openmv/openmv/commit/661169f85>`__,
`772bfab26 <https://github.com/openmv/openmv/commit/772bfab26>`__

Migration checklist
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Re-validate any :class:`machine.ADC` readings and timing-sensitive capture code
against the aligned ADC driver and full MDMA offload
(:ref:`the behavior changes <v4_0_2_behavior>`). All other scripts run
unchanged.