.. _changelog_v3_4_0:

v3.4.0
======

v3.4.0 adds an **SSD1306 OLED driver**, enables the MicroPython :mod:`framebuf`
module, raises the H7 to **480 MHz**, lets **Ctrl-C interrupt scripts over a
UART REPL**, and improves the CMSIS-NN library and MAVLink optical-flow
examples. It introduces **no breaking API changes** — v3.3.1 scripts run
unchanged.

.. contents:: On this page
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Highlights
----------

- **SSD1306 OLED driver** added.
- :mod:`framebuf` module enabled.
- **H7 at 480 MHz** — higher clock for more performance.
- **Ctrl-C over UART REPL** — scripts can be interrupted from a UART REPL.
- **No breaking API changes** — reflash and your v3.3.1 scripts run
  unchanged.

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

- Added an SSD1306 OLED display driver.
- Enabled the MicroPython :mod:`framebuf` module.
- Added TV-shield, distance-shield, and IMU-shield examples.

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

- Raised the H7 to 480 MHz (updated H7 clocks); updated the CMSIS-NN library
  to use non-square NN functions and updated the NN / CIFAR-10 models (with
  logging enabled in the NN scripts); include ``frozen_mpy.o`` when compiling
  a frozen module.

Bug fixes
---------

Camera and system:

- Fixed the SCCB / I2C timing for the F7 and H7 (moved SCCB timing into the
  board config files), the H7 SD clock, and the OpenMV 2 filesystem.

Scripting and connectivity:

- Allowed Ctrl-C to interrupt scripts over a UART REPL, set the WINC
  ``ioctl`` function, fixed a missing ``break`` in ``py_net_search``, and
  fixed the MAVLink optical-flow example scaling/direction (with a green
  flashing LED and always sending flow packets regardless of quality).

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

v3.4.0 introduces **no breaking Python API changes**. Scripts that ran on
v3.3.1 run unchanged on v3.4.0 — just reflash the firmware. (Note: the bundled
MAVLink optical-flow example's scaling/direction was corrected; re-check
downstream consumers of its output.)