ESP32-P4 micropython port

[kerekesg]

Just in case anyone would need to run micropython on the ESP32-P4, you can get a build firmware from here:

https://codeberg.org/kerekesg/micropython-olimex-esp32-p4

AI helped me, but it works well on my Olimex ESP32-P4 board.

[LubOlimex]

Thank you for this, I am sure someone will find it helpful!

[puhuri]

I was testing ESP-P4-DevKit (rev D1) ethernet on micropython. Seems that I cannot find the right set of parameters to initialize connection.

With vanilla Micropython ESP32_P4 v1.29 (PRE_V3 variant:(sysname='esp32', nodename='esp32', release='1.29.0', version='v1.29.0 on 2026-08-24', machine='Generic ESP32P4 with pre revision 3 chip with ESP32-P4')) the error message is OSError: esp_eth_driver_install failed with invalid argument for all the cases.

With kerekesg firmware (sysname='esp32', nodename='esp32', release='1.27.0-preview', version='v1.27.0-preview.339.gbe4892097e.dirty on 2025-10-23', machine='Olimex ESP32-P4-DevKit with ESP32-P4') the error is a bit more useful:

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E (30570) esp_eth: esp_eth_driver_install(209): can't set eth->mac or eth->phy to null
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
I've tried several intialization parameters but no luck (leaving some parameters out and trying out variations). The most correct I think is (based on schematic and micropython source):

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lan=network.LAN(0, mdc=Pin(31), mdio=Pin(52), phy_type=network.PHY_IP101, phy_addr=1,  reset=Pin(51), ref_clk=Pin(50), ref_clk_mode=0)
but that fails with above error. With kerekesg firmware there seems to be an issue with GPIO configuration as Pin(52) results "ValueError: invalid pin" (Pin(32) works fine, for example).

The ref_clock_mode is a bit guess, 0 is input AFAIK but tried also 1.

Would just want to use wired network connection for a location as the wifi connection there is a bit spotty.

Have not yet tried to compile own firmware (with updated micropython), just trying to first check that it is not something trivial I'm missing here.

[puhuri]

Now had time to look at it more.

The modifications and instructions from kerekesg is a good base. The major issue is that one need build PRE_REV3 variant.

So my workflow was following. Clone both the micropython and the above repo according to their instructions.

Copy modified files over:

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cd micropython
cp -r ../micropython-olimex-esp32-p4/board-files/OLIMEX_ESP32_P4 ports/esp32/boards/
cp ../micropython-olimex-esp32-p4/board-files/sdkconfig.p4 ports/esp32/boards/
cp ../micropython-olimex-esp32-p4/board-files/sdkconfig.riscv ports/esp32/boards/
cp ../micropython-olimex-esp32-p4/board-files/dependencies.lock.esp32p4 ports/esp32/lockfiles/
cp ports/esp32/boards/ESP32_GENERIC_P4/mpconfigvariant_PRE_REV3.cmake ports/esp32/boards/OLIMEX_ESP32_P4/

I used docker image (with podman) for interactive session (did run low with diskspace so need to check old photos had been backup to NAS  ).

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docker run --rm -v $PWD:/project -w /project -e HOME=/tmp -it espressif/idf:release-v5.5

Then within container commandline run:

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cd ports/esp32 && make BOARD=OLIMEX_ESP32_P4 BOARD_VARIANT=PRE_REV3

And once compilation completed without major error (reported some re#defines warnings), just cd ports/esp32/build-OLIMEX_ESP32_P4-PRE_REV3 and write to board.

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PORT=/dev/serial/by-id/usb-Espressif*
esptool --port $PORT --chip esp32p4 -b 460800 --before default-reset --after hard-reset write-flash "@flash_args"

I'm using MQTT_AS package, so one needs to install github:peterhinch/micropython-mqtt/mqtt_as_eth instead and define

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import mqtt_as_eth in python initialization. The normal mqtt_as does use WLAN-dependent code that won't work. Successfully connects to MQTT server and communicates messages  . Next up some soldering, but that is for later.