DART-MX8M Android Camera

DART-MX8M - Android Oreo - Camera

Overview

The DART-MX8M is capable of driving video input via MIPI CSI-2 cameras.

The CSI-2 Host Controller is a digital core that implements all protocol functions defined in the MIPI CSI-2 specification,
providing an interface between the system and the MIPI D-PHY,
this allows communication with a MIPI CSI-2 compliant camera sensor to host processor bus.
The Key features include:

• Module provides Two four-lane MIPI camera serial interfaces.
• MIPI D-PHY specification V1.2 (Board Approved).
• Compliant to MIPI CSI2 Specification V1.3 except for C-PHY feature (Board Approved).
• Support primary and secondary Image format.
  • YUV420, YUV420 (Legacy), YUV420 (CSPS), YUV422 of 8-bits and 10-bits.
  • RGB565, RGB666, RGB888
  • RAW6, RAW7, RAW8, RAW10, RAW12, RAW14
  • All User-defined Byte-based Data packet.
• Support up to 4 lanes of D-PHY, which operates up to a maximum bit rate of 1.5 Gbps/lane.
• Interfaces:
  • Compatible to PPI (Protocol-to-PHY Interface) in MIPI D-PHY Specification.
  • AMBA3.0 APB Slave for Register configuration.
  • Image output data bus width: 32 bits.
• Image memory:
  • The size of SRAM is 4KB.
• Pixel clock can be gated when no PPI data is coming.

Note:

• At present OV5640 supports only YUV 422 image format.

MIPI-CSI2

The DART-MX8M exposes two MIPI-CSI input ports of the SOC.
Refer to: https://www.variscite.com/wp-content/uploads/2018/03/DART-MX8M-datasheet.pdf for more details.

Hardware Availability and Setup

Make sure you have the camera(s) connected to the board before booting.

• DART-MX8M Development Kit:
  • CSI1 - MIPI Clock + 4 Data lanes are accessible via the Carrier board header.
  • J11: MIPI - 4 Lane + CLK + I2C + GPIOs.
    
  • MIPI Camera Accessories Required: https://www.variscite.com/product/accessories/var-ext-cb8/

Note:

• DART-MX8M platform doesn't have the SOC-based Image Signal Processing (ISP) unit to convert bayer data to RGB and YUV.
• DART-MX8M platform relies on the MIPI camera to convert the Bayer data to YUV format.
• For maximum, supported resolution and combinations refer to the datasheet.

Software Setup

Make sure you have the required hardware as per above.

MIPI Cameras

By default, MIPI cameras are supported out of the box.
Android System / Vendor images contain Camera HAL already support for OV5640 5MP support available.
You don't need to do any special build/addition below HAL if you are using the standard camera.
Unless you wish to modify it for your custom camera type,

• For Android Oreo:

Source Path: <android_build>/vendor/nxp-opensource/imx/libcamera3/

Note:

• Android 8.0 and above Camera2 APIs are standard.
• Camera2 APIs are supported out of the box.
• Legacy Camera1 APIs should also work.
• Auto Focus, Manual Focus, Auto Exposure, and Manual Exposure are not supported at present.

Testing Camera

If the camera is connected/configured correctly. Once you click the Android Camera Application mentioned below.

It will ask you for location, and storage permissions, click on allow and then click next.

• The camera preview should start
  
• Click on the Camera icon, it will take a JPEG snapshot.

If you wish to record/video, click on the leftmost side of the preview screen you will see moving UI.
Click on the Video Recording Button.
Snapshot:

• JPEG snapshot with maximum 5MP supported

Video Recording:

• Encoding upto 480@30fps (Software based)