You can use OpenPnP's Actuator system to turn lights on and off in response to camera capture events.

1. For new machine configurations, the light actuators are already setup.
2. Otherwise, add an actuator for the lights you want to control. Go to the Machine Setup tab and then look for the Camera you want to assign the light to. You'll find it either attached to the Machine (up-looking Camera) or to the Head (down-looking Camera). Got to the Actuators branch besides the Cameras branch and then click the green + button to add a new Actuator.
3. Expand the Actuators list and select the new Actuator.
4. Set up the Actuator as described in the Actuators page. If you have multi-channel lights, be sure to read about the Actuator Profiles.

If both camera lights are switched by the same controller output, you need a shared light actuator, otherwise OpenPnP will be confused about the actuator switching state. In this case you best delete the LIGHT_TOP actuator and also use the LIGHT_BOTTOM actuator for the Top camera. You need to enable the Allow Machine Actuators? checkbox for it to be selectable (by default only head mounted actuators are selectable for head mounted cameras). Also, you need to disable Anti-Glare? on both cameras:

Of course, you can then rename the shared actuator to simply LIGHT or similar.

The created Light Actuator can now be assigned to the camera:

There are various ON and OFF actuation Options:

• ON at Before Capture: actuate the Light Actuator before computer vision captures a camera image. This happens before the Camera Settling. See the ImageCapture Stage section to control pipeline specific light actuation values and profiles. NOTE: This option should almost always be enabled.
• ON at User Camera Action: actuate the Light Actuator ON when a user action is deliberately positioning or otherwise using the camera.
• OFF at After Capture: actuate the Light Actuator OFF after computer vision captured a camera image.
• OFF at Anti-Glare: prevent this camera light from blinding another camera, it is actuated OFF before any other camera is capturing an image. Only cameras looking the other way (up/down) are taken into consideration (see the Looking field).

As soon as a Light Actuator is assigned, the Camera View will display a new overlay light symbol in the upper right corner. It shows the camera light status and can be clicked to turn the light on or off:

Alternatively, go to Main Window -> Machine Controls -> Actuators and click the button named after the created Actuator. Your lights should come on. Click it again and they should turn off. If this doesn't work, adjust your settings until it does, or ask for help.

Every computer vision pipeline typically contains the ImageCapture stage to capture an image from the camera:

As soon as the camera has a Light Actuator assigned, the ImageCapture stage can control the lighting.

If the defaultLight property is switched on (default) the Default ON value of the actuator will be used to determine the lighting. If it is switched off, the light property comes into play.

The light property controls the lighting for this specific pipeline (if defaultLight is off). The user interface responds to the Value Type of the actuator, i.e. it can be a checkbox for lights that can only switch ON/OFF, it can be a number for lights that can be controlled in intensity, or it can be an Actuator with Profiles combo box to control multi-channel lights:

As an alternative to controlling the actuators directly from OpenPnP, you can use scripts to do so. This was the only option in earlier versions of OpenPnP, so this documentation is mostly kept in order to support the older versions.

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Not recommended for new machines!

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The following is for (legacy) OpenPnP 2.0 version only, for versions 1.0 see further below.

For newer versions of OpenPnP 2.0, you must use the Camera.BeforeSettle/Camera.AfterSettle scripts, instead of the Capture ones. See also Scripting#CameraBeforeSettle, Scripting#CameraAfterSettle and the page about Camera Settling.

1. Download the zipfile containing the scripts
2. Expand the zipfile. There should be two scripts inside.
3. Go to Main Menu -> Scripts -> Open Scripts Directory.
4. In the folder that opens, open the Events directory.
5. Copy the two scripts into the Events directory.

Now, whenever OpenPnP needs to capture an image from your Up looking camera it will run the Camera.BeforeSettle.js script, settle the camera and capture an image and then run the Camera.AfterSettle.js script. The first one will turn the lights on and the second will turn the lights off.

You can customize the way this works by modifying the scripts or the Gcode that controls the lights.

If you want to control the Down camera lights, just add another Actuator called DownCamLights. The script is already set up to use it.

The following is for OpenPnP 1.0 only:

1. Download the zipfile containing the scripts to your desktop or somewhere else you can easily find it.
2. Expand the zipfile. There should be two scripts inside.
3. Go to Main Menu -> Scripts -> Open Scripts Directory.
4. In the folder that opens, open the Events directory.
5. Copy the two scripts into the Events directory.

Now, whenever OpenPnP needs to capture an image from your Up looking camera it will run the Camera.BeforeCapture.js script, capture an image and then run the Camera.AfterCapture.js script. The first one will turn the lights on and the second will turn the lights off.

You can customize the way this works by modifying the scripts or the Gcode that controls the lights.

If you want to control the Down camera lights, just add another Actuator called DownCamLights. The script is already set up to use it.

Here is a short video showing the steps above: https://www.youtube.com/watch?v=Y4DbYY9a9BQ

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