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The HDP board comes equipped with a 24-pin connector (J14) which carries MIPI signals enabling a MIPI-compatible camera to be fitted to the board.

Compatibility

The MIPI alliance does not define a standard connector type for fitting camera devices.  However, the J14 connector is compatible with the LI-OV5640-MIPI-AF which comprises a 24-way connector (AXK824145), ribbon cable and the OmniVision OV5640 MIPI CMOS Sensor Module.  This is a 5 megapixel sensor module supporting up to 30fps @ 1080p.

Fitting the camera to the board

The Panasonic AXK824145 connector is designed to "click" into its locked position, so when inserting the camera connector into J14 you should feel the connectors "click" together to indicate the mating is completed.

 

Electrical Damage Warning

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The J14 connector is symmetrical and it is therefore possible to incorrectly insert the camera module which may lead to damaging the camera. Take care to ensure the correct pin number alignment by observing the markings (1, 12, 13 and 24) on the ribbon cable and PCB near J14 connector.

 

MIPI camera detection and registration

No software configuration changes should be needed for the camera module to be detected.  The OV5640 is an I2C device with bus address 0x3C and should be detected during boot-up with the following message in the dmesg logs:

[    4.705538] camera ov5640_mipi is found

 

 

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If your camera module is not detected you will see the following in the boot logs:

[ 4.495786] ov5640_read_reg:write reg error:reg=300a
[ 4.495807] camera ov5640_mipi is not found

Go back and check that your camera module is properly connected to J14 and with the right connector orientation.

 

Assuming your camera module has been correctly detected during boot-up we can now load the video capture driver by entering modprobe mxc_v4l2_capture.  This will generate an expected error message ERROR: v4l2 capture: slave not found! (this can be safely ignored).

Normally the camera module will be registered as /dev/video1.  You can confirm this by typing the command cat /sys/class/video4linux/video1/name and you should obtain the output Mxc camera.  If you do not obtain this output then your camera might be registered to a different video device index.

Running a simple test

Assuming your camera is registered as /dev/video1 then we can stream a real-time image to whatever display device is connected (i.e., HDMI or LCD) by entering the following command:

  1. Enter gst-launch mfw_v4lsrc device=/dev/video1 ! mfw_v4lsink to launch a GStreamer pipeline which will output capture video data to the display device.

 

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If the device parameter is omitted, it defaults to /dev/video0. You can substitute device=/dev/video1 for another video device if your camera was not registered as /dev/video1.

 

 

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