Camera interfaces on Jetson TK1
The Jetson TK1 board provides several different interfaces that allow camera input:
- USB 3.0 port (supports many USB 2.0 or USB 3.0 webcams). Additional USB 3.0 ports can be added through mini-PCIe, eg: mini-PCIe (untested).
- USB 2.0 port (through a micro-B to female USB-A adapter, that is sometimes included with Jetson TK1).
- Gigabit Ethernet port. Additional Gigabit or Dual-Gigabit Ethernet ports can be added through mini-PCIE, eg: mini-PCIe (untested).
- CSI-2 MIPI dual camera ports (one 4-lane camera port and one 1-lane camera port) through the GPIO expansion port.
- Firewire (available through mini-PCIe), eg: mini-PCIe (untested).
- Analog video capture cards, available through mini-PCIe (eg: mini-PCIe (untested)), USB 3.0 (eg: USB 3.0 (untested)), or USB 2.0 (eg: USB 2.0 (untested)).
USB 2.0 (480 Mbps) is the most common & cheapest method for camera input, since USB 2.0 webcams range from $5 - $200. However, USB 2.0 is the slowest of the possible camera interfaces, so it usually only supports upto 720p 30fps (eg: Logitech C310 $45 (untested)),(except for the few USB 2.0 cameras supporting 1080p video compression, such as Logitech C910 (untested)). Logitech C910 is known to work on Jetson TK1 in uncompressed modes but has not been tested in 1080p compressed mode.
Disabling USB auto-suspend
The L4T 19.2 OS includes automatic suspending of inactive USB ports to save power. This can cause problems with some USB devices & cameras, so you might need to disable USB auto-suspend mode:
sudo bash -c 'echo -1 > /sys/module/usbcore/parameters/autosuspend'
To disable USB auto-suspend on bootup, you could put "echo -1 > /sys/module/usbcore/parameters/autosuspend" into one of your bootup scripts, such as "/etc/rc.local" with root permissions (untested).
USB 3.0 (5 Gbps) has enough bandwidth to allow sending uncompressed 1080p video streams. But USB 3.0 hasn't reached the mass consumer market like USB 2.0 has, so USB 3.0 cameras are still limited to expensive professional-grade cameras. eg: 1080p 120fps (untested) or 1080p 30fps (untested).
Enabling support for USB 3.0
Note that early versions of Jetson TK1 don't come with USB 3.0 support enabled, and thus you might need to enable USB 3.0 support and re-flash your whole L4T system. According to the L4T R19.2 Release Notes, you should modify the odmdata settings in "jetson-tk1.conf" to enable USB 3.0:
# USB 2.0 operation on USB2 port(J1C2 connector)/for use as root device use ODMDATA=0x6009C000; # USB 3.0 operation on USB2 port(J1C2 connector) use ODMDATA=0x6209C000, requires firmware load from userspace or initial ramdisk ODMDATA=0x6209C000;
Then flash your L4T system and reboot.
"IP Cameras" are fairly easy to find and tend to be a good option. Gigabit Ethernet cameras (1 Gbps) has enough bandwidth for uncompressed 1080p video streams. eg: GigE cameras (untested) or regular IP network cameras. Some IP cameras provide a URL where M-JPEG frames are available.
Firewire has been used for professional video capture for a long time, since Firewire cameras do a lot of both the compression and the data transmission in hardware and thus don't put nearly as much stress on the host CPU compared to USB.
CSI is the ideal method for camera input, since the cameras are tiny and the images can be processed directly by the ISP rather than needing to be stored into the computer's DRAM first before processing. eg: 720p 60fps (untested). However there isn't a single standard for CSI cameras, thus each customer typically designs their own connector that is specific to a camera module and a computer or ISP.
Specialized camera sensors
- Stereo cameras (eg: Bumblebee 2) (untested).
- Time-Of-Flight 3D depth "RGBD" cameras (eg: Microsoft Kinect is known to work, see details below).
- Night-vision or Thermal-imaging Infrared cameras, typically with interfaces similar to standard cameras.
Microsoft Kinect TOF 3D Depth camera
Then you need to follow the Kinect Manual Installation Guide rather than the many x86 based guides, since the Tegra CPU uses ARM architecture.
To see which video capture devices you have available:
To see the supported video formats of your webcam:
sudo apt-get install luvcview luvcview -d /dev/video0 -L
You can also use luvcview to record video from your webcam to a video file. It will open a GUI window showing the camera preview. Then along the middle of the bottom row there are 4 rectangle buttons, click the bottom-left of the 4 buttons to start/stop video recording, and the bottom-right button to quit. To record video using the default settings of your webcam:
luvcview -o out.avi
To record video using a custom resolution (of those shown when running luvcview -L above):
luvcview -o out.avi -s 640x480
Normally, guvcview can be used to adjust default camera settings, but it seems that the default guvcview is not working correctly on ARM due to a kernel change.
When testing a "Full HD 1080p" USB 2.0 webcam containing a Realtek chipset, the same speeds & resolutions worked on Jetson TK1 as on the x86 desktop running Linux (ie: 640x480 @ 30 FPS, 960x720 @ 15 FPS, and 1920x1080 @ 15 FPS). Note that many webcams will run slower if there is low lighting, so for example, it might be 30 FPS when pointed at a bright light but only 10 FPS when pointed at a shadow.