Support for CSI-2

[Will_Robertson]

I'm wondering if anyone has any advice re. microcontroller (#MCU) support for #CSI-2?

ST application note AN5478 "STM32MP135 line interfacing with a MIPI® CSI-2 camera" written in 2023 seems to be the best reference that I can find on this and uses the STMIPID02 MIPI CSI-2 deserializer.

https://www.st.com/resource/en/application_note/DM00697325.pdf

SD do provide an internal peripheral for CSI-2:

https://wiki.st.com/stm32mpu/wiki/CSI_internal_peripheral

ST application note AN5470 on #STM32MP15x "STM32MP15x Series interfacing with a MIPI® CSI-2 camera" written in 2020 and updated in 2023 uses the same deserializer and says that:

"it is possible to extend the range of addressable camera sensors for instance MIPI® CSI-2 cameras (camera serial interface), thanks to the STMIPID02 MIPI CSI-2 deserializer discrete component"

https://www.st.com/resource/en/application_note/dm00693021-stm32mp15x-series-interfacing-with-a-mipi-csi2-camera-stmicroelectronics.pdf

The "D3 DesignCore camera mezzanine board OV5640" referred to in AN5470 was designed in 2017 and no longer seems to be available in 2024.

ST made this CSI-2 camera board available in August 2024:

https://www.st.com/en/evaluation-tools/steval-cam-m0i.html

One workaround for microcontrollers that don't support CSI-2 may be that some cameras support #I2C - I2C fast mode or I2C fast-mode plus - I don't know if these can reach the same transmission rates as CSI-2 though nor how well supported they are - and careful design can be needed to avoid problems with interference in I2C buses.

One other option I'm looking at is the #SAMA7G54 "New 1 GHz SAMA7G54 is the First Single-Core MPU with MIPI CSI-2 Camera Interface" which was launched in 2022.

https://www.microchip.com/en-us/about/news-releases/products/new-1ghz-sama7g54-is-the-first-single-core-mpu-with-mipi-csi-2

The Analog Devices #MAX78002 data sheet dated 2022 states

"Multiple high-speed and low-power communications interfaces are supported, including I2S, MIPI® CSI-2® serial camera"

https://www.analog.com/media/en/technical-documentation/data-sheets/MAX78002.pdf

This field is rapidly changing so I've included dates in the above.

CSI-2 is supported by SBCs for example the Raspberry Pi Camera Module 3 (Sony #IMX708 ) with a Raspberry Pi SBC however the power consumption of SBCs is significantly higher than microcontrollers and I haven't found any SBC that can rapidly wake from a low power sleep mode in the way that some microcontrollers can.

https://datasheets.raspberrypi.com/camera/camera-module-3-product-brief.pdf

[STOne-32]

Dear @Will_Robertson ,

You can refer to our STM32MP25 : Arm® based dual Cortex®-A35 1.5 GHz + Cortex®-M33 MPU, AI, 3D GPU,
video encoder/decoder, TFT/DSI/LVDS, USB 3.0, PCIe

 

Datasheet - STM32MP251A/D STM32MP253A/D STM32MP255A/D STM32MP257A/D - Arm® based dual Cortex®-A35 1.5 GHz + Cortex®-M33 MPU, AI, 3D GPU, video encoder/decoder, TFT/DSI/LVDS, USB 3.0, PCIe®

It supports natively Camera CSI-2 

Hope it helps you.

STOne-32.

 

[Will_Robertson]

Dear @STOne-32 ,

Thank you very much! That looks a great match for what we need!

Would this be the best evaluation board to try?

https://wiki.st.com/stm32mpu/wiki/Category:STM32MP25_Evaluation_boards

Will

[PatrickF]

Hi @Will_Robertson 

 

Both boards listed below are suited for STM32MP2 Camera evaluation :

STM32MP257F-EV1

STM32MP257F-DK (available in some weeks)

Choice between both depend on which final application you want to evaluate before going to develop your own board/product.

EV1 is more industrial oriented (3 x Ethernet, DDR4 USB2.0, PCIe, FDCAN, DSI, CSI, LVDS)

DK is more consumer oriented (USB3.0, LPDDR4, HDMI, WLAN/BT, audio, CSI, LVDS)

 

You might need to purchase camera and display separately:

7" LVDS 1024x600 Display B-LVDS7-WSVGA

5MP CSI Camera + inertial motion unit + Time‑of‑Flight sensor B-CAMS-IMX

 

Note that STM32MP2x products are not MCUs but MPU. I.e. intended first to run Linux on Cortex-A processor and bare metal coprocessing on Cortex-M processor.

Many information also on ST MPU wiki : https://wiki.st.com/stm32mpu/wiki/Main_Page

 

Regards.

[Avgerinos]

Hello,

I had the same question and the STM32MP25 seems a solution to use for a MIPI CSI-2 input.
But I was wondering if there is an alternative IC to the STMIPID02 MIPI CSI-2 deserializer?

My main goal is to be able to interface a MIPI CSI-2 video input to a STM32F7 series MCU.
For this reason I am looking for a solution on how can I convert a MIPI CSI-2 to parallel interface that would be compatible with the DCMI peripheral.

Thank you

[Will_Robertson]

HI @Avgerinos 

I was also looking at using the STMIPID02 MIPI CSI-2 deserializer between a CSI-2 camera and high end MCU but I was hoping that I could find a monolithic solution that avoids the extra complexity of a separate deserializer chip.

For our application it looks like the STM32MP25 may be able to wake fast enough from a low power sleep state to be a viable alternative to an MCU but I think you're right that there will be some applications where getting CSI-2 directly into a high-end MCU like the STM32F7 series would be valuable.

Will