This page will cover the content on the official website’s “Getting Started” page.
Limelight takes a 12V input, but is built to function down to 6V. Its LEDs have a constant brightness down to 7V.
Limelight will receive software updates for improvements and features to accomodate the game if necessary.
Only connect the microUSB cable while imaging. Limelight enters a special flash mode while the microUSB cable is connected. You will not be able to access the web interface while Limelight is in flash mode.
We highly reccomend following the static IP instructions for reliability during events.
Follow these steps before starting:
- Go to add/remove programs in windows, and search for “bonjour”
- How many items do you see?
- If there are two (2) items with “bonjour” in their names, uninstall “bonjour print services”
- If there are no (0) items with “bonjour” in their names, install bonjour from our Downloads page.
- Reboot your robot and computer.
- Download the Limelight Finder Tool
- Follow the steps listed below.
- Why do we reccommend a static IP?
- First, it shaves multiple seconds off Limelight’s boot time. Second, teams have historically had issues with DHCP assignment and mDNS responders on actual FRC fields and with event radio firmware.
We recommend setting static IP addresses on your robo-rio and driverstation as well. The networking settings to use on all of these devices can be found near the bottom half of this web page: https://wpilib.screenstepslive.com/s/currentCS/m/troubleshooting/l/319135-ip-networking-at-the-event
- How do I reset the IP address?
- After your Limelight has booted, hold the config button on the front face of the camera until the LEDs start blinking. Power-cycle your robot, and your Limelight will have an automatically-assigned IP address.
- If the above steps do not fix the problem, install Angry IP scanner and find the address for your limelight.
- Go to <limelightaddress>:5801, and give your limelight a .11 static IP.
- From this point onward, you can rely on the static IP to access the page.
For now, we just need to get data from the camera to your robot. Limelight posts targeting data to Network Tables at 100hz. The default update rate for NetworkTables is 10hz, but Limelight automatically overwrites it to allow for more frequent data transfer.
To get started, we recommend reading four values from the “limelight” Network Table as frequently as possible. Our code samples will show you exactly how to do this. The offsets to your target (in degrees) are sent as “tx” and “ty”. These can be used to turn your robot, turn a turret, etc. The target’s area, sent as “ta”, may be used a rough indicator of distance to your target. Area is a value between 0 and 100, where 0 means that your target’s hull area is 0% of the total image area, and 100 means that your target’s hull fills the entire image. The rotation or “skew” of your target is returned as “ts”. If all values are equal to zero, no targets exist.
In addition, you may control certain features by setting values in NetworkTables. See the complete NT API here: Complete NetworkTables API
Read the following from the “limelight” table
|tv||Whether the limelight has any valid targets (0 or 1)|
|tx||Horizontal Offset From Crosshair To Target (-27 degrees to 27 degrees)|
|ty||Vertical Offset From Crosshair To Target (-20.5 degrees to 20.5 degrees)|
|ta||Target Area (0% of image to 100% of image)|
Write the following to the “limelight” table
|ledMode||Sets limelight’s LED state|
|0||use the LED Mode set in the current pipeline|
|camMode||Sets limelight’s operation mode|
|1||Driver Camera (Increases exposure, disables vision processing)|
|pipeline||Sets limelight’s current pipeline|
|0 .. 9||Select pipeline 0..9|