STM32N6-DK : what STM does not tell you - you need USB-C power adapter

[tjaekel]

I have ordered STM32N6570-DK board in order to start working on STM32N6 MCU.
But I was confused how to set it up. And STM does not tell you. Here, what I have figured out:

1. Orientation of PFC cable for camera:
Place the contacts of the FPC cable towards the PCB (you should see still the blue plastic cover and the text on cable in normal orientation of setup).
The camera module and its connector is very delicate: make sure not to lose the black bridge used in order to tighten the cable: I lost my one immediately somewhere under my desk.

2. You need an USB-C power supply!

Nobody tells you, but what I found:

The board - WITHOUT the camera activated - draws already 470..480mA of current (e.g., via USB-A from USB hub to USB-C on DK board).

If you activate now the "AI" feature on the demo, where the camera is activated and "should" show you the live video on LCD screen: all remains dark, both LEDs are red and even NRST button does not work (does not bring back the board to live).

You need: a real USB-C wall adapter, an USB-C power supply!
Using USB-A to USB-C from PC or even a powered USB Hub does not provide enough current.
You "must" have a real USB-C power supply, providing above 500mA of current (I have used a Raspberry Pi USB-C power adapter - this works, but USB hub to USB-C does not!).

3. Sharpen the video image

My video image was not sharp: maybe I twisted already the camera lens. Anyway: the lens can be focused: it can be twisted, even you do not feel anything happening. But it is the optical focus for the camera.

No idea what the focal point is: try to focus the camera looking into your face, try to focus the camera with objects in a far distance (it seems to be slightly different how much to twist the lens).
No idea how to get the sharpest image.

Summary
A great MCU, a great board. But why STM does not tell us which power supply to use (a regular one with just 500mA is not enough). No idea first how to assemble the FPC cable. And the camera side connector is very "delicate" (fragile).

Happy AI coding with this great MCU...

[RomainR.]

Hello @tjaekel 

You can follow the UM3300 section 7.4.2 STLK (for compatibility with legacy USB Host port)
Every day, we use the same STM32N6570-DK boards with the out-of-the-box demo and many other applications that require high power on the USB ports of our laptops. I don't have the problems you describe.
For example, I can use 2 DKs simultaneously on my HP laptop, as follows:
- One STM32N6570-DK connected between the STLINK-V3 CN6 USB-C connector to a USB 3.2 Gen 1 port delivering up to 900 mA (4.5 W) as standard, 1.5 A (7.5 W).
- A second DK connected between CN6 and a Thunderbolt 4 Type-C port, delivering up to 3 A (15 W).
Do you have USB enumeration problems that prevent your machine from exceeding 100mA?
Can you try with another computer?

Best regards,

Romain,