.. _changelog_v4_3_1:

v4.3.1
======

v4.3.1 adds VL53L5CX multi-zone time-of-flight support, improved CAN FD, an
auto-closing ``ImageIO`` finalizer, and a broad set of camera, USB, and
soft-reboot reliability fixes.

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

Highlights
----------

- **VL53L5CX** multi-zone time-of-flight sensor support (Python module +
  examples).
- **Improved CAN FD** support on STM32.
- ``ImageIO`` auto-close — streams now close themselves when garbage
  collected.
- **Breaking:** stdout is now buffered — see the breaking change.

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

- **VL53L5CX** — new VL53L5CX multi-zone ToF sensor Python module, ST driver,
  and ToF example scripts.
- ``ImageIO`` finalizer — an ``ImageIO`` stream is now closed
  automatically when the object is garbage collected.
- **CAN FD** — improved CAN FD support on STM32.
- **Multi-device I2C buses** — the camera bus scan can return multiple
  devices, and the FIR thermal sensors support buses shared with other
  devices; the RP2 port gained I2C general-call support.

Bug fixes
---------

Image processing:

- Fixed a ``quad_segment_maxima`` memory leak (AprilTag/quad detection), the
  SIMD YCbCr→RGB color conversion, black lines on the first frame, and LCD
  cache usage on the OpenMV Pure Thermal.

Camera and sensors:

- Fixed MLX9064x frame-read synchronization, VSYNC EXTI handling on the
  Portenta H7 / STM32, and the Arduino Nicla Vision power-supply mode and
  HSE clock value.

System and USB:

- Fixed the USB High-Speed endpoint descriptor offset, module de-init on the
  ``main.py`` → IDE transition, soft-reboot cleanup (``mp_deinit()`` and CDC
  buffer reset), the nRF ``sys.path`` initialization, and the RP2 I2C
  fast-mode-plus frequency.

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

- **VL53L5CX** multi-zone ToF sensor.
- **OpenMV Cam H7** — larger frame line buffer (handles wider images).
- **Arduino Nicla Vision** — power-supply and clock fixes.

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

User-visible API breaks between v4.3.0 and v4.3.1.

The only breaking change is a *behavior* change (same API, different timing).

.. _v4_3_1_stdio:

Buffered stdout *(behavior)*
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Standard output is now buffered. ``print()`` output may not appear on the
host/IDE immediately — it is flushed on a newline or when the buffer fills.
Scripts that depended on character-by-character unbuffered output should add
an explicit flush (or print a newline) where immediate output is required.

*Commit:* `8cddada54 <https://github.com/openmv/openmv/commit/8cddada54>`__

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

Only output timing is affected: add an explicit flush where you rely on
immediate ``print()`` output (:ref:`the buffered-stdout change <v4_3_1_stdio>`).
All other scripts run unchanged.