STM32 USB Camera (UVC) Evaluation Board and Controller Support ?

[Sakthi_IND]

Hi Team,

We are planning to use an STM32 camera interface over USB using the UVC protocol in our upcoming design. We would like to understand if there are any evaluation or development boards available that can be used for initial testing.

Our key requirements are as follows:

• Image size: up to 5 MB per capture
• Capture interval: one image every 30 seconds (worst case)
• Video streaming is not required; we only need still image capture and transfer
• USB-based camera interface preferred

We would like to know:

1. Whether UVC is suitable for this type of non-streaming, low-frame-rate image transfer
2. If anyone has implemented a simpler or similar design successfully
3. Which STM32 controller models support this use case
4. Availability of any development or evaluation boards for testing the camera over USB

Please share your recommendations, reference designs, or documentation links if available.

Looking forward to your guidance.

Regards,
Sathiya

[Gyessine]

Hello @Sakthi_IND 
you can use the snapshot capture example and modify it a little bit to take a frame each 30 seconds automatically instead of capture mode and lower the fps I think it will be simpler
to answer your questions, for testing purposes, you can start with STM32H747I-DISCO.
This board already includes example for streaming a camera over USB and another example for taking snapshots and displaying them on the board screen.
BUT I doubt that you can get 5MB image size from it, is it a mandatory requirement?
BR
Gyessine

[Sakthi_IND]

Hello Gyessine,

Thank you for your response and the suggestion to use the snapshot capture example. That approach makes sense, and we agree that modifying the example to automatically capture one frame every 30 seconds with reduced FPS should simplify the implementation.

Regarding your question: yes, the 5 MB image size is a mandatory requirement for our application. The image is used for post-processing and analysis on the host side, so reducing resolution or compression significantly may not be acceptable for us.

Based on this requirement, we would like to understand:

1. Is it practically feasible to achieve a 5 MB still image using the STM32H747I‑DISCO (sensor, memory, USB bandwidth, and UVC constraints considered)?
2. Are there any known limitations or issues (RAM, DCMI throughput, USB UVC frame size, latency) when handling such a large image?
3. Is there any proven STM32-based development board or reference design that supports similar image sizes over USB (UVC or alternative USB class)?
4. If UVC becomes too limiting for this use case, would you recommend:
   • A USB bulk transfer–based custom device, or
   • Any alternative STM32 family / external processor solution that has been successfully used for large still-image capture?

Any recommendations for other architectures, controllers, or evaluation boards that could reliably support 5 MB still image capture every 30 seconds would be most welcome.

Looking forward to your guidance.

BR,
Sathiya

[Gyessine]

Hello @Sakthi_IND 
>yes, the 5 MB image size is a mandatory requirement
Can you clarify whether you mean 5 megapixels or 5 megabytes?
If you mean 5 megapixels, the B-CAMS-OMV camera modules already provide 5 MP resolution and are compatible with the provided examples.
If you mean 5 megabytes, can you specify the resolution and image format required to achieve a 5 MB file size?
The existing example of STM32H747_DISCO using B-CAMS-OMV camera modules can support resolutions such as 640 × 480. 
 the STM32N6570_DK also can serve your purposes it also has a Ux_Device_Video example that supports 800*480 resolution using the B-CAM-IMX camera module
If this resolution is insufficient, you can try to modify project and see if it can supports your resolution if you have the proper screen

for STM32N6570-DK, To test other stream change number of included file "ux_device_video.c":

- stream1 FORMAT : MJPEG and Width = 320, Height = 236.

It also have a Snapshot example that supports 800*480 resolution.

>Are there any known limitations or issues (RAM, DCMI throughput, USB UVC frame size, latency) when handling such a large image?
the STM32H747_DISCO supports a 256 Mbit SDRAM and the N6570_DK supports a256-Mbit Hexadeca‑SPI PSRAM so it should be enough to handle this image size
BR
Gyessine

[Sakthi_IND]

Hello Gyessine,

Thank you for the detailed clarification and for sharing information on the available examples and development kits.

To confirm, our requirement is for a 5‑megapixel image (sensor resolution), not a fixed 5‑megabyte file size. The final file size will depend on the selected image format (RGB/JPEG), but maintaining 5 MP resolution is mandatory for our application.

Based on your feedback, we would like to seek clarification on the following points:

1. B‑CAMS‑OMV with STM32H747I‑DISCO
   Can the B‑CAMS‑OMV 5 MP camera module be reliably used with STM32H747I‑DISCO in snapshot mode (non‑streaming) for full 5 MP resolution capture?

2. Snapshot mode vs UVC
   If we focus on snapshot mode rather than UVC streaming, are there any recommended STM32 reference projects or best practices you suggest for USB image transfer?

3. Higher resolution support
   The default examples support resolutions such as 640×480 or 800×480. Have you or the ST team validated support for higher snapshot resolutions (up to 5 MP) with project modifications?

4. Memory considerations
   Given the available external memory (SDRAM on STM32H747I‑DISCO and PSRAM on STM32N6570‑DK), are there any known practical limitations or risks when buffering a full 5 MP frame?

5. Alternative platforms
   If STM32H747I‑DISCO presents limitations at 5 MP, would you recommend STM32N6570‑DK or any other STM32 platform as a more suitable option for high‑resolution snapshot capture over USB?

As a next step, we plan to begin evaluation using STM32H747I‑DISCO and assess feasibility for 5 MP snapshot capture. Your guidance on recommended camera configuration, pixel format, or USB class choice for this use case would be highly appreciated.

Thank you again for your support.

BR,
Sathiya

[Sakthi_IND]

Hi Gyessine,

Our use case is to connect 5MP Camera over USB using UVC to one of above MCUs variants and stream images (preferably JPEG) over local network. Pls advise if STM32H74, 75, 7A, 7B series can support camera over USB supporting UVC driver (other camera interface like mipi or DCMI are not preferrable)

Will it be still possible to leverage the HW encoder/acceleration support in this case?

BR,
Sathiya

[Gyessine]

Hello @Sakthi_IND 
To conclude
>B‑CAMS‑OMV with STM32H747I‑DISCO
The B-CAMS-OMV and STM32H747I-DISCO are hardware capable of handling 5 MP snapshots every 30 seconds in the worst case. However, modifications are required for the available examples, as they support only up to 800 × 480 resolution.
>Snapshot mode vs UVC
You can use the UVC example directly, as it already implements the USB image transfer function. The STM32H747I-DISCO supports USB high-speed operation, which should be capable of handling the image size load.
 >Memory considerations
Memory requirements depend on the format and compression used. Modifications to the software are necessary for both the UVC and snapshot examples. Using 5 MP resolution with the current examples will cause the SDRAM to overflow. You need to modify the existing project. For the webcam example, you can work on the relevant lines in main.c:

uint8_t pCameraLineBuffer[CAMERA_LINE_SIZE] __attribute__ ((aligned (32), section (".sram1")));
uint8_t pCameraBuff[CAMERA_BUFF_SIZE] __attribute__ ((aligned (32), section (".sdram_bank1")));
uint8_t pCopiedBuff[CAMERA_BUFF_SIZE] __attribute__ ((aligned (32), section (".sdram_bank2")));
uint8_t pYCbCrBuff[YCBCR_BUFF_SIZE] __attribute__ ((aligned (32), section (".sdram_bank2")));
uint8_t pJpegBuff[JPEG_MAX_SIZE] __attribute__ ((aligned (32), section (".sdram_bank2")));

>Alternative platforms 
If the STM32H747-DISCO failed to cover your requirements, yes, I recommend using the STM32N6570_DK
>Will it be still possible to leverage the HW encoder/acceleration support in this case?
All of STM32H7 Series devices support the hardware JPEG decoding.
You can seek UM2222 section 6.5, UM2611 section 3.2.10 and AN4996 for, more details
BR
Gyessine

[Sakthi_IND]

Hi Gyessine,

Thank you for your detailed response and clarifications.

We have one additional clarification request regarding the USB interface and UVC camera support, as well as a question related to the documentation links you referenced.

USB interface & UVC camera support (clarification)

Our understanding is that STM32H7 series variants with USB High‑Speed capability (STM32H74 / STM32H75 / STM32H7A / STM32H7B), as well as the STM32N6570 series, can operate in USB Host mode and are able to interface with a USB camera compliant with the UVC (USB Video Class) standard, using the available USB Host UVC software example.

In other words, these devices should be able to support a camera connected purely over USB, without relying on other camera interfaces such as DCMI or MIPI CSI‑2.
Kindly confirm if this understanding is correct.

Hardware JPEG acceleration – documentation access

You mentioned that:

All STM32H7 Series devices support the hardware JPEG decoding.
You can seek UM2222 section 6.5, UM2611 section 3.2.10, and AN4996 for more details.

At the moment, we are not able to open the referenced links/documents.
Could you please share:

• Direct URLs for these documents, or
• Confirm if there is a more recent or consolidated reference document that describes HW JPEG encoding/decoding usage, especially in a USB UVC camera use case?

This will help us better understand how to leverage the hardware JPEG accelerator in our application.

Thank you again for your support.

Regards,
Sathiya

[Sakthi_IND]

Hi Gyessine,

I hope you are doing well.

Could you please confirm the points discussed in my previous email regarding USB interface support, specifically the ability to connect and operate a USB UVC‑compliant camera in USB Host mode on the mentioned STM32 devices?

Your confirmation will help us finalize the MCU selection and corresponding development board for our design.

Thank you in advance for your support and clarification.

Regards,
Sathiya

[Gyessine]

Hello @Sakthi_IND 
>At the moment, we are not able to open the referenced links/documents.
 have updated the links. Please consult them, as they should contain answers to your JPEG encoder questions. You need to adapt the usage of JPEG encoders and decoders for your USB application.
You can also consult this WIKI if you are referring to the video encoder (VENC), which is available in the STM32N6 series.
>these devices should be able to support a camera connected purely over USB, without relying on other camera interfaces such as DCMI or MIPI CSI‑2.
the STM32N6570-DK has an UVC host example has a UVC host example that you can run to test this functionality. The readme states that you only need to connect a USB webcam to the USB port, so your statement is correct.
>Your confirmation will help us finalize the MCU selection and corresponding development board for our design.
For the final configuration, I recommend checking with your field application engineer (FAE) for the final choice.
I hope that I have answered your questions.
This thread contains a variety of questions, so for moderation reasons and so other users can benefit from this current discussion.  If you have any other questions, please post them in a new thread and accept the reply that answers your question. 
BR
Gyessine