QUESTION: WHAT IS THE CAMERA BUS TYPE

[mjs513]

@iabdalkader - @pillo79 - @facchinm

Kind of curious on something. For the camera configurations I noticed that Zephyr defines bus-type as define in video_interface.h as:

#define VIDEO_BUS_TYPE_CSI2_CPHY 1
#define VIDEO_BUS_TYPE_CSI1      2
#define VIDEO_BUS_TYPE_CCP2      3
#define VIDEO_BUS_TYPE_CSI2_DPHY 4
#define VIDEO_BUS_TYPE_PARALLEL  5
#define VIDEO_BUS_TYPE_BT656     6

so question I have is what is the bus-type on the giga, h7 midcarrier and the nicala vision?

One reason I am asking is that I am trying to get the OV5640 working on the giga and the H7 mid carrier.

On the GIGA camera fails to start no matter what clock I am using.

On the H7 camera is starting but not receiving any frames, i.e., nothing appears queues up

[josuah]

There are several protocols that allow data to be moved between a camera.
The most two widespread are parallel ports (with VSYNC, HSYNC, PCLK and DATA0..7), and MIPI CSI2 (like on Raspberry Pi boards. often with 15-pin and 20-pin flat connectors).

Parallel port is lower tech, does not support going over long distance, and low speed due to each signal just being one pin.
This stops at lower resolution sensors, and this is what most MCUs currently support.

Embedded Linux systems (MPU) as well as some MCUs like i.MXRT1170, STM32N6, ESP32P4... start making use of MIPI-CSI to reach higher resolution, longer cable length, wider choice of sensors, at relatively low power.

For the Arduino Giga or Arduino Portenta H7, this would all be VIDEO_BUS_TYPE_PARALLEL.

Image sensor drivers such as OV5640 have a MIPI variant and a DVP (parallel port) variant. The bus-type allows to specify which variant you actually connect. For instance, MIMXRT1170_EVK comes with a MIPI-CSI OV5640 module, but Adafruit, Waveshare, Arducam... provide OV5640 with parallel ports with this well-known 2-rows of 20/18 pin headers.

It is part of describing which hardware is effectively present, for the sake of configuring drivers accordingly.

Here is one place where you may find where all these configuration parameters are defined:

• https://github.com/zephyrproject-rtos/zephyr/blob/main/dts/bindings/video/video-interfaces.yaml

And here is the source of inspiration for it:

• https://github.com/torvalds/linux/blob/master/Documentation/devicetree/bindings/media/video-interfaces.yaml