Camera interface

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On this page you will find useful informations on how to use the Camera/CMOS Sensor Interface (CSI) of the i.MX chip found on your APF board. Currently only the APF27 & APF6 are supported.

Hardware

APF27

  • All the signals of the i.MX27 CSI interface can be found on the J9 connector of the APF27Dev development board.
  • You should connect an external camera/sensor compatible with the CSI interface (8bits data bus) to see something ;-). Here are the tested sensor models:
  • All these sensors are controllable through an I2C interface. The one on J8 connector of APF27Dev can for example be used.

APF6

  • APF6Dev boards have a wandcam (OV5640) compatible connector (near the PCIexpress one).
  • MIPI bus is used on APF6Dev

Driver

  • From now we consider that you have a supported camera module plugged on your development board
  • CSI interface can be driven through the V4L2 (Video For Linux) standard interface as soon as CSI/MIPI driver is loaded:
APF27 APF6 (kernel 3.19+)
# modprobe mx27_camera
  • Then you have to load your camera driver in order for him to "attach" to the CSI one (for example for the OV9653):
 # modprobe ov96xx
# modprobe -a mx6-camera mipi-csi2 ov5640-mipi


  • Now it's up to you to configure your camera with the tools/API the camera driver is offering...

Test

  • We have a small SDL/V4L2 app to quickly test that your camera is working properly (you will also need a LCD interface): target/demos/camera/capture/
    • it may be installed by default on your rootfs depending on your Buildroot defconfig.
    • to launch it (here to have a 640x480 camera image on a LW700 TFT):
# capture --width 640 --height 480 --cam_width 640 --cam_height 480
  • To trigger autofocus (APF6 with 3.19+ kernel):
# v4l2-ctl -c auto_focus_start=1

Going further

Links