.. _changelog_v4_2_1:

v4.2.1
======

v4.2.1 adds Nano RP2040 DHT11/DHT22 sensor support and more MT9V0xx camera
variants, plus ImageIO, WiFi, and framebuffer-cache fixes. Image transfer is
now MDMA-offloaded by default — read the breaking change below.

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

Highlights
----------

- **Nano RP2040 Connect** — DHT11 / DHT22 temperature/humidity sensor
  support.
- **More MT9V0xx variants** — MT9V022 / MT9V024 / MT9V032 / MT9V034.
- **ImageIO** now handles all modes and older files; framebuffer-cache and
  ``copy_to_fb`` fixes.
- **Breaking:** image transfer is now MDMA-offloaded by default — see the
  breaking change.

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

- **Nano RP2040 Connect** — added DHT11 and DHT22 sensor support.
- **MT9V0xx camera variants** — the MT9V0xx driver now supports the
  MT9V022 / MT9V024 / MT9V032 / MT9V034 sensors.

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

- The "frozen module not found" console message is no longer printed.
- Nano RP2040 Connect ships with default fresh-filesystem contents.

Bug fixes
---------

- Fixed the built-in person-detector model labels.
- Fixed ``ImageIO`` to support all modes and older recording files.
- Fixed ``copy_to_fb`` when targeting an existing image, and the framebuffer
  cache is now invalidated before use (prevents corrupted image data).
- Fixed the NINA WiFi driver (Nano RP2040 Connect) and a :class:`machine.Timer`
  flag specification bug.

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

- **Arduino Nano RP2040 Connect** — DHT11/DHT22 sensors, default I2C/file
  setup.
- **MT9V0xx** — MT9V022/024/032/034 variant support.

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

User-visible API breaks between v4.2.0 and v4.2.1.

The only breaking change is a *behavior* change (same API, different
results) — re-check timing-sensitive captures.

.. _v4_2_1_mdma:

Image transfer is MDMA-offloaded by default *(behavior)*
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Image transfers are now fully offloaded to MDMA by default on capable boards.
This speeds up capture but changes the transfer path and timing — re-check
scripts that depended on the previous (non-offloaded) capture timing.

*Commit:* `e6cc4223d <https://github.com/openmv/openmv/commit/e6cc4223d>`__

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

Only timing-sensitive capture code is affected: re-validate any timing
assumptions around image capture given the new default MDMA offload
(:ref:`the MDMA-offload change <v4_2_1_mdma>`). All other scripts run
unchanged.