Hi everyone,
I would like to report a reproducible fan control issue on my Arduino VENTUNO Q.
Hardware and software:
- Arduino VENTUNO Q (16 GB RAM / 64 GB eMMC)
- Ubuntu 24.04.4 LTS
- Arduino App Lab 0.10.0
- Arduino Zephyr board platform 1.0.0
- STM32H5 MCU
- Tested both with and without the Arduino UNO Media Carrier
1. Normal operation – MPU only
When running an Arduino App Lab application containing only main.py, without sketch.ino, the fan operates normally.
The application runs normally and displays:
Hello world!
Fan measurements:
fan1_input = 0 RPM
pwm1 = 0
fan1_fault = 0
The Hello world! output is simply a basic example showing that an MPU-only application runs correctly.
I have also successfully developed and tested a more complete MPU-only application for recording and playing WAV audio files, using a custom Brick, ALSA and a WebUI.
This application works correctly, with no abnormal fan behavior observed.
The fan issue appears when launching an application that also uses the MCU, even with an empty Arduino sketch.
I have also used Firefox and Arduino App Lab for more than five hours without using the MCU, with no abnormal fan behavior observed.
2. Abnormal operation – MCU enabled
I created another App Lab application containing a minimal, empty Arduino sketch:
void setup() {
}
void loop() {
}
No additional Bricks are required.
When launching this application, the fan starts running at high speed and remains there.
Measurements taken during the issue:
fan1_input = 5368 RPM
pwm1 = 0
fan1_fault = 0
On another occasion, I measured 5274 RPM, also with pwm1=0 and fan1_fault=0.
During previous occurrences, CPU temperature was approximately 28°C, despite the fan running at high speed.
The problem has also occurred with my GPS application and another test application. It is therefore not specific to the code of a particular sketch.
In previous tests, a complete power-off and power-on restored normal fan behavior.
Once the fan starts running at full speed after launching an MCU sketch, stopping the application in Arduino App Lab does not stop the fan. Even completely closing Arduino App Lab has no effect: the fan continues running at approximately 5,300 RPM.
In my tests, only a complete power-off and power-on of the VENTUNO Q restored normal fan behavior.
Despite the OpenOCD errors and the abnormal fan behavior, the application runs correctly, including the MCU sketch. The issue appears to affect the fan control rather than the application's functionality.
3. OpenOCD errors
During MCU programming, Arduino App Lab reports errors including:
Error: [stm32h5x.cpu] Execution of event examine-end failed
Error: Translation from khz to adapter speed not implemented
Error: [stm32h5x.cpu] Execution of event reset-start failed:
.../target/stm32h5x.cfg:250: Error:
{adapter speed} 480
The log also identifies the STM32H5 MCU and continues through the flashing procedure and application container startup.
I do not know whether these OpenOCD errors are related to the fan issue, but I am including them because they occur during the same MCU launch sequence.
4. Observations
- MPU-only applications: normal fan behavior in the tests performed.
- Applications using the MCU: fan runs at approximately 5300 RPM.
- The issue occurs even with an empty sketch.
- The Arduino Q Media Carrier is not required to reproduce the issue.
- The fan speed remains high despite
pwm1reporting zero.
I would appreciate any guidance on whether this could be related to the MCU programming/reset sequence, OpenOCD, or the fan controller.
I can provide additional diagnostic measurements if needed.
Before attempting a complete system reflash, I would prefer to wait for my NVMe SSD, which should arrive shortly, so I can first investigate backup options for my current installation.
Thanks in advance!
P.S. I only noticed this fan issue very recently. Until now, I have mainly been developing and testing applications that use the MPU only, without involving the MCU.
As far as I remember, I have used very few applications involving both the MCU and MPU, possibly only my UNO-Q-GPS project.
Therefore, I cannot say when this issue first appeared or whether it was already present before the recent system updates.