METEO P4 frequently asked questions

Windows does not detect the device

Connect METEO P4 directly to the computer with a USB data cable. Try another cable and USB port. Then open Device Manager → “Ports (COM & LPT)”.

If a COM port already appears, the CH341SER driver is usually not required.

Two COM ports appear. Which one should I use?

METEO P4 may appear as two USB JTAG/serial debug unit ports, for example:

For flashing and Serial Monitor, use the lower COM number — COM11 in this example. Always confirm the selected port using chip-id before erasing flash.

“Access is denied” or COM port is busy

Close ESP-IDF Monitor, Arduino IDE, PuTTY, another terminal, or any program that may be using the COM port. Then retry the command.

BIN file is not found

Verify the full firmware file path before erasing the device:

Continue only when the command returns True.

esptool does not detect ESP32-P4

Check the cable, selected COM port and direct PC connection. Use:

Do not erase flash until the command displays ESP32-P4 information.

Flashing fails at 460800

Use a lower write speed:

Python or esptool does not start

Close regular PowerShell and open ESP-IDF 6.0.1 PowerShell from the Start menu.

If the commands still fail, open Espressif Installation Manager and repair ESP-IDF 6.0.1.

Screen remains off after flashing

Wait for the automatic reboot. If the display still remains off, press RESET once or reconnect power.

Wi-Fi does not connect immediately

After entering the Wi-Fi password, wait 1–2 minutes. Do not press buttons or restart the device during this time.

MQTT data does not arrive

Check the MQTT broker address, Wi-Fi connection and device status. On the server, you can inspect publishing with:

When everything works, you will see meteo_p4/status online and sensor values.

Home Assistant cannot see METEO P4

Make sure the Home Assistant MQTT integration uses the same broker. METEO P4 publishes Discovery configuration through homeassistant/.../config topics.