Camera interface

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:
  • OV9653 / OV9655
  • OV7670
  • OV3640
• 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 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 you 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
# 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 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

Going further

• Using the i.MX27 video codec

Links

• Video4Linux