.. _changelog_v4_8_1:

v4.8.1
======

v4.8.1 is a maintenance release on top of v4.8.0 — camera and IDE-streaming
fixes, a PAG7936 image-quality improvement, and a new GenX320 event-mode
bias-tuning script. It introduces **no breaking API changes**: scripts that ran
on v4.8.0 run unchanged on v4.8.1.

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

Highlights
----------

- **OV5640 fixed on 400 MHz OpenMV H7 cameras** — the pixel clock is now scaled
  for 400 MHz H7 parts instead of being driven at the 480 MHz rate.
- **PAG7936 image quality** — the sensor driver now applies bad-pixel
  correction.
- **IDE frame-buffer streaming fixes** — raw transfer over the legacy V1
  protocol and the raw-stream → JPEG fallback both work correctly again.
- **New GenX320 bias-tuning script** for event-streaming mode.
- **No breaking API changes** — reflash and your v4.8.0 scripts run unchanged.

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

- **GenX320 event-mode bias tuning** — a new
  ``genx320_event_mode_biases.py`` example for tuning the GenX320 event sensor's
  biases while running in event-streaming mode.
  (`f2e4e234c <https://github.com/openmv/openmv/commit/f2e4e234c>`__)

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

- **PAG7936 bad-pixel correction** — the PAG7936 global-shutter sensor driver
  now applies bad-pixel correction, improving image quality on boards using
  that sensor.
  (`b405fa176 <https://github.com/openmv/openmv/commit/b405fa176>`__)
- **Alif Device Family Pack updated to 1.3.4** — the Alif I2C/I3C driver was
  updated to match, affecting :class:`machine.I2C` on Alif (AE3) boards.
  (`7388ef403 <https://github.com/openmv/openmv/commit/7388ef403>`__,
  `d79086cdc <https://github.com/openmv/openmv/commit/d79086cdc>`__)

Bug fixes
---------

Camera and sensors:

- OV5640 pixel clock is now reduced for 400 MHz STM32H7 OpenMV H7 cameras
  (H7 Plus boards are 480 MHz); it was previously driven too fast on 400 MHz
  parts.
  (`cd9bb2d09 <https://github.com/openmv/openmv/commit/cd9bb2d09>`__)
- Fixed the one-shot capture configuration on the STM32 DMA multi-buffer path.
  (`61ffb7403 <https://github.com/openmv/openmv/commit/61ffb7403>`__)

Host/IDE streaming:

- Fixed the raw-stream → JPEG fallback: the destination image width/height and
  ``PIXFORMAT_JPEG`` are restored after raw-stream processing, so JPEG capture
  and streaming after a raw stream work correctly.
  (`36a8b627b <https://github.com/openmv/openmv/commit/36a8b627b>`__)
- Fixed raw frame-buffer transfer over the legacy V1 (USBDBG) protocol,
  restoring reliable IDE frame-buffer preview.
  (`75963a623 <https://github.com/openmv/openmv/commit/75963a623>`__)

Firmware update:

- Fixed the bootloader not exiting its main loop after a DFU detach on some
  hosts (a USB-polling thread on the host kept the device mounted), so
  ``dfu-util`` / OpenMV IDE reliably reset the board after flashing.
  (`3a1e8dab7 <https://github.com/openmv/openmv/commit/3a1e8dab7>`__)

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

- **OpenMV H7** — the OV5640 pixel clock is now scaled for 400 MHz H7 units
  (480 MHz on H7 Plus).
- **PAG7936** — bad-pixel correction is applied by the sensor driver.
- **Alif (AE3)** — Device Family Pack 1.3.4 with an updated I2C/I3C driver.

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

v4.8.1 introduces **no breaking Python API changes**. Scripts that ran on
v4.8.0 run unchanged on v4.8.1 — just reflash the firmware. The only
fork-facing changes are build/tooling.

.. _v4_8_1_tooling:

Build / tooling *(tooling)*
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

None of this affects MicroPython scripts. ``.dfu`` image generation was dropped
from the STM32 and i.MX RT ports (the files were unused). The bootloader now
embeds a header and encodes its version in the USB ``bcdDevice`` so host tools
and firmware can identify the bootloader version at runtime; an STM32
combined-image padding bug was fixed, the ROMFS resource build (``mkromfs``)
was parallelized, and the Alif Device Family Pack moved to 1.3.4. See the
`firmware repository <https://github.com/openmv/openmv>`__ history for
fork-relevant detail.

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

Nothing to do — reflash the firmware; your v4.8.0 scripts run unchanged.