v3.8.0

v3.8.0 updates the core to MicroPython 1.13, freezes a large set of helper libraries into the firmware, adds Portenta Ethernet (with networking examples), HDMI CEC support to the lcd module, pyb.CAN baudrate/sampling-point configuration, and a wave of H7 low-power and HAL fixes. The time / utime modules were merged and F4 pyb.DAC DMA was disabled — read the breaking changes below.

Highlights

  • MicroPython 1.13 — the bundled MicroPython core was updated.

  • Frozen libraries — uasyncio, mqtt, rpc, rtsp, modbus, bno055, pid, ssd1306, and more are now frozen into the firmware.

  • Portenta Ethernet — Ethernet support plus HTTP / SSL / peer-to-peer examples.

  • HDMI CEC — new CEC API in the lcd module (Pure Thermal).

  • pyb.CAN — bit timing from baudrate / sampling_point keywords.

  • Breaking: the time / utime modules were merged and F4 pyb.DAC DMA functions were disabled — see the breaking changes.

New features

  • Frozen manifest — uasyncio, mqtt, rpc, rtsp, modbus, bno055, mutex, pid, ssd1306, tb6612, and vl53l1x are now frozen into the firmware on OpenMV 3 / 4 / 4 Plus / Pure Thermal / Portenta.

  • Portenta Ethernet — enabled Ethernet with http_client, http_client_ssl, and peer_to_peer examples.

  • HDMI CEC — added an HDMI CEC API to the lcd module (Pure Thermal).

  • pyb.CAN — the constructor / init() now derives bit timing from baudrate and sampling_point keywords (the manual prescaler form still works); CAN examples updated accordingly.

Other changes and improvements

  • The REPL banner now includes the HAL version string; the Audio FFT example was updated for the newer ulab API.

Bug fixes

Camera and sensors:

  • Fixed the OV2640 sensor clock and OV5640 PCLK frequency scaling on STM32H7 rev Y devices; recover the FIR I2C bus from an arbitration-lost state by pulsing SCL, and retry AMG8833 init on an F7 soft-reset.

Power and timers:

  • Fixed H7 low-power (stop/standby) entry — voltage scaling for rev V, re-enabling the oscillator/PLL on wake, SDRAM low-power with DRAM retention, disabling Systick on stop entry, and enabling DBGMCU only in debug builds. Fixed the machine.Timer HAL state after the H7 HAL update and reverted the SD read/write IRQ priority change.

Display and connectivity:

  • Fixed the F4 SPI LCD 8/16-bit data-size config (wrong MCU_SERIES define), returned an error on WINC1500 SPI bus-init failure instead of silently continuing, and used a static SPI handle to avoid WINC1500 SPI bus conflicts. Fixed a MicroPython GC-collect bug.

System:

  • unittests.py no longer marks the suite failed when a test is disabled or unavailable; removed the broken Thermopile-shield camera_lcd examples.

Hardware and board support

  • OpenMV Pure Thermal — board updated and renamed (OPENMVPURETHERMAL → OPENMVPT), with HDMI CEC.

  • OpenMV 2 — OV2640 camera driver enabled.

  • Arduino Portenta H7 — Ethernet support.

Breaking API changes

User-visible API breaks between v3.7.0 and v3.8.0. Scope: Python C-modules in modules/ and Python libraries in scripts/libraries/.

Each change is tagged with its impact:

  • minor — narrow API; only affects scripts that used it.

  • behavior — same API, different results; re-check tuned scripts.

Changes are grouped by impact in that order. If you just want to port your code, jump to the migration checklist at the end. Each commit hash links to its diff on GitHub.

time / utime modules merged (minor)

The time and utime modules were merged and the OpenMV clock class moved to utime. All bundled examples were updated to import utime / clock = utime.clock(). Scripts that relied on import time for the clock class should import utime instead.

Commits: 20587f308

F4 pyb.DAC DMA functions disabled (minor)

On F4-based boards, pyb.DAC functions that require DMA were disabled because the F4 heap lives in CCM, which is not DMA-accessible. F4 scripts that used DAC DMA-buffer writes must avoid those functions.

Commits: d61f236f2

MicroPython updated to 1.13 (behavior)

The bundled MicroPython core was updated to 1.13. Standard-library and language behavior follows upstream MicroPython 1.13; re-check scripts that depend on version-specific micropython / standard-module behavior.

Commits: fb0a5e26d

cpufreq supported frequencies are revision-dependent (behavior)

More CPU frequencies were added and made silicon-revision aware: cpufreq.get_supported_frequencies() now returns a revision-dependent list on the H7 (50/100/200/400 MHz on rev X/Y, 60/120/240/480 MHz on rev V). Scripts that hard-coded a frequency from the old fixed list should query the supported list at runtime.

Commits: 825dd0742

Migration checklist

For a clean port to v3.8.0 the typical work is:

  1. Change import time to import utime where you use the clock class (the time/utime merge).

  2. On F4 boards, stop using pyb.DAC DMA-buffer functions (the F4 DAC change).

  3. Re-validate scripts that depend on version-specific MicroPython behavior against 1.13 (the MicroPython bump) and query cpufreq.get_supported_frequencies() at runtime instead of hard-coding (the cpufreq change).

All other scripts run unchanged.