Connecting to Your LumenPnP V3 and Configure Bottom Camera

Now that OpenPnP is installed and the LumenPnP configuration files have been placed in the hidden system folder, OpenPnP can start with some basic preconfigured settings. The next step is to connect your LumenPnP and get familiar with OpenPnP’s user interface..

Then, we will install the N045 and N24 nozzle tips to help us with calibration.

Finally, we will configure your bottom camera by establishing a connection to it, and setting the correct exposure.

Prepare for Connection

Before launching OpenPnP, follow these guidelines to ensure a smooth connection:

USB Connection Order Matters!

Always plug in your LumenPnP’s USB cable before launching OpenPnP.

If OpenPnP is already open, close it before connecting the USB.

Camera USB Ports

Plug cameras directly into your computer using separate USB ports.

Avoid USB hubs, as they may not provide enough bandwidth for the cameras.Use separate USB ports directly into your computer. The cameras require a lot of USB bandwidth, and many USB hubs aren't capable of handling it. For best results, make sure each camera is plugged into a different USB port directly into your computer, ideally on different internal USB hubs.

Connecting to Your LumenPnP V3

Follow these steps in order:

Always Plug In Barrel Jack First

Always plug in the barrel jack before USB power. This ensures the proper power up sequence for the LumenPnP motherboard. When plugging in the barrel jack, always make sure the USB type B connector is unplugged.

Ensure OpenPnP is closed.
Power the LumenPnP by plugging in the barrel jack power cable.
Connect the LumenPnP to your computer using the included USB cable.
Connect both cameras using their USB cables.
Launch OpenPnP. You should now see the OpenPnP user interface:

Configuration the Serial Port

Before OpenPnP can communicate with the LumenPnP, we need to set the correct serial port.

Open Machine Setup
- Click the Machine Setup tab, toward the top right section of OpenPnP.
Expand the Configuration Trees
- Check the Expand checkbox toward the top right of OpenPnP to show all machine configuration options.
- This will expand all of the categories, and sub-categories, in the upper pane of Machine Setup and will require you to scroll to see all of the options mentioned below.
Select the Gcode Driver
- In the upper pane, locate the newly expanded Drivers category and click on GcodeDriver GcodeDriver.
Choose the Correct Port
- Under the Serial Port section in the Configuration tab, select the correct Port from the dropdown menu:
  - Linux: Select the Port formatted as ttyACM#. (Examples ttyACM0, ttyACM1, ttyACM2, etc.)
  - Windows: The Port will be labeled as COM#. (Examples COM1, COM2, COM3, etc.)
  - Mac: Look for a Port in the format of cu.usbmodemXXXX, where XXXX is a series of numbers.
Apply and Save
- Click Apply in the lower right corner to save your changes.
- Save your OpenPnP configuration: File > Save Configuration.

Port Not Found?

If your machine's port isn't listed:

Ensure the USB cable is securely connected on both sides.
Make sure the motherboard is powered on.
Close OpenPnP, press the reset button on the control box, wait a few seconds, and reopen OpenPnP.
Finally, use our Debug Tool and see if you are able to connect your LumenPnP there.

Establishing a Serial Connection

Connect OpenPnP to Your Machine
- Click the green power button in the Machine Controls section (Bottom left of OpenPnP).
Confirm Connection
- If successful, the green power button will turn red. This means OpenPnP has successfully connected to your machine.
- If unsuccessful,review your Serial Port Connection.
Turn On Ring Lights
- In the bottom left corner of OpenPnP, go to Machine Controls.
- Click the Actuators tab.
- Click the LED button.
- Then press On.
- Close the LED window.
- Switch back to the Jog tab so you are ready to move the nozzles in the following steps.
Keep Ring Lights On

Keep the ring lights on for the rest of calibration. All calibrations should be based on the lighting from the ring lights. Once calibration is complete and running a job on the LumenPnP, OpenPnP will automatically control the ring lights as needed, eliminating the need for manual operation during normal use.

Preparing for Homing

Level the nozzles before homing.

🚨 Critical Warning: Level Nozzles Before Homing 🚨

Before pressing the homing button—now and every time in the future—you must ensure that your nozzles are level.

⚠️ Failure to do this can cause crashes and potentially damage your machine.

OpenPnP does not remember the previous nozzle positions from the last homing sequence, meaning it cannot adjust movements based on past alignment. If the nozzles are not level before homing, they may collide with the machine, leading to misalignment or serious hardware damage.

Note

Use the P between the Z-axis up/down arrows located in Machine Controls toward the bottom right of OpenPnP. This ensures the nozzle tips are out of the way.
The P stands for Parking the nozzle out of the way into a safe height that won’t collide with any objects. If nothing happens after you click the P button, that means the nozzles are at a safe height already.

Nozzles not level after parking.

The nozzles may not be level when clicking the “Park” button, which is okay. The nozzle only moves to the point that it reaches the “safe zone” and then stops.
Click the Home button to perform a rough homing sequence.
- The Nozzles will move to X, Y, and Z zero positions (front-left corner of the LumenPnP) and park there.
  
  This image shows a V4 homing, but the end location is the same for both versions.

If your machine does not move fully to the front left

If your LumenPnP does not move all the way to the front left of the machine when you click the Home icon, it could mean that your sensorless homing values need to be adjusted.

Instructions for tuning this setting are here.

Install the Nozzle Tips

Locate Your Nozzle Tips and SuperLube tube.
- Find and remove the N045 and N24 nozzle tips in the nozzle rack that is mounted on the staging plate.
- Remove the SuperLube Tube that comes in the LumenPnP V3 Tool Bag.
Lubricate both brass nozzles.
- Apply a small amount of SuperLube to the brass nozzles. This prevents damage to the rubber O-rings when mounting nozzle tips. We pre-lubricate them before shipping, but adding extra ensures longevity.
Automatic Nozzle Tip Swapping

OpenPnP supports automatic nozzle tip swapping, but we don’t recommend it yet due to inconsistent performance. This feature will be improved in a future update, and the nozzle tip rack will be mounted on the staging plate. Most jobs can be completed using an N045 on one nozzle and an N24 on the other.
Mount the N045 Nozzle Tip onto Nozzle: N1.
- In OpenPnP, navigate to Machine Setup > Heads > ReferenceHead H1 > Nozzles > ReferenceNozzle N1.
- Select the Nozzle Tips tab, and check the Loaded? checkbox for the N045 row.
- Your machine will jog the head to the front of the machine for easy tip loading.
- A ”Task Interrupted:” window will pop up. This is not an error! OpenPnP is just notifying you that the job has been stopped if one is running. This is normal and can be dismissed.
- Slide the N045 nozzle tip (the one with the smaller opening) onto the left nozzle (using red tubing). Rotate the nozzle tip as you mount it to the brass nozzle to evenly distribute the lubricant around the O-rings. It should slide on and off smoothly after working it in.
Mount the N24 Nozzle Tip onto Nozzle: N2.
- In OpenPnP, navigate to Machine Setup > Heads > ReferenceHead H1 > Nozzles > ReferenceNozzle N2.
- Select the Nozzle Tips tab, and check the Loaded? checkbox for the N24 row.
- Don’t forget. It will move to the second nozzle and you’ll see the ”Task Interrupted:” popup window again.
- Slide the N24 nozzle tip (the one with the larger opening) onto the right nozzle (using blue tubing). Rotate the nozzle tip as you mount it to the brass holder to ensure the grease works its way into the tip and around the O-rings. It should slide on and off easily after working it in.
Why These Nozzle Tips?

The N045 and N24 nozzle tips cover the vast majority of parts without needing swaps. We highly recommend keeping them as the default and only swapping when absolutely (e.g., for very heavy parts).

Configuring the Bottom Camera

Before calibration, the bottom camera and exposure must be set up properly. We will need to install a nozzle tip and position it above the bottom camera to properly adjust the exposure.

Which Reticle should I use?

We use the "Ruler" Reticle in the following steps. If you prefer to use the same reticle style that we use, right-click on the top or bottom camera feed and choose Reticle, then "Ruler" to match our docs photos best.

Note

From the LumenPnP V3 and up, machines ship with a more recessed bottom camera, as ween in the photo below. The images in our setup guides mostly show an older mounting solution, but either works the same.

🚨 Remove Lens Caps 🚨
- ⚠️ Ensure both the top and bottom cameras have their lens caps removed.
Navigate to the Bottom Camera's Device Settings tab in OpenPnP
- Navigate to Machine Setup > Cameras > OpenPnpCaptureCamera Bottom > Device Settings tab.
Choose the Correct Camera Device
- In the Device Settings tab, select LumenPnP Bottom from the Device dropdown.
Duplicate Camera Names

If two cameras appear with the same name, select one—if incorrect, choose the other. This is a bug within OpenPnP.
Set Resolution and Frame Rate
- In the Format drop-down menu, select 1280x720, 10FPS. A low frame rate is crucial to avoid bandwidth/performance issues.
Apply and Verify
- Click Apply to save the Bottom Camera settings. One of the red "X"s in the camera feed should disappear. The image might be entirely black, but we'll fix that in the following steps.

Adjust Bottom Camera Exposure

Other Camera Settings

In the following step, do not modify any camera settings other than exposure. The default values should remain unchanged.

Select Nozzle: N1.
- From the Machine Controls dropdown, select Nozzle: N1 - N045 (Head:H1).
Positioning 'Nozzle: N1' Over the Bottom Camera
- Using the Machine Controls, jog Nozzle: N1 to be roughly centered above the datum board.
- Set the Distance slider to 0.1 or 0.01 for when you need more precise movements.
- Lower Nozzle: N1, using the Z-axis controls, until the nozzle tip is barely touching the datum board. (The very edge of the datum board has been ideal for easily seeing how close it is before Nozzle: N1 barely makes contact). Lowering it to the same height as the datum board ensures the nozzle is at the correct Z-height before calibration.
- Keeping the Z-height unchanged, jog Nozzle: N1 to be centered over the bottom camera feed.
Adjust the bottom camera exposure using the slider.
- Return to Machine Setup > Cameras > OpenPnpCaptureCamera Bottom to adjust the exposure. This will help us through the rest of the calibration.
- 🚨 Keep all other camera settings at their default value, and only adjust the exposure slider.
- In the OpenPnpCaptureCamera Bottom go back to the Device Settings tab.
- Located the Exposure slider and click on the check box labeled Auto. The camera will attempt to find the correct exposure.
- Then, uncheck the Auto box to ensure we are now in "manual adjustment" mode.
- Using the jog controls, fine-tune the nozzle tip location to be perfectly centered over the bottom camera's reticle. You can use your mouse scroll wheel to zoom in on the feed for more precision.
- Right click on the bottom camera's feed and select Show Image Info? to enable the image info card. This will give you the brightness histogram of the image.
- Use the histogram as a general guide rather than a precise measurement—it’s a helpful tool but not exact. For the best results, refer to the comparison photos below, which show examples of 'too bright,' 'too dark,' and 'good exposure' to help you fine-tune your settings after using the histogram.
- In the next step, we'll be aiming for a sharp peak on the right side and a larger cluster to the left in the histogram. See the image below for reference.
🚨 Important 🚨

The reference image above is just an example—your histogram may look very different depending on lighting conditions, camera placement, and other environmental factors. Do not try to match it exactly. Instead, focus on achieving the key characteristics: a distinct peak on the right and a noticeable cluster, or peak, to the left. Adjust gradually until the image is clear and well-exposed.
Set the Correct Exposure.
- Adjust the exposure slider, or enter varying manual exposure values, to ensure the camera can clearly detect the dark hole in the nozzle tip for calibration. The exposure should be balanced—bright enough to distinguish the nozzle tip from the background but not so bright that the hole becomes difficult to detect. Aim for a setting where the brightest areas are visible but do not appear completely white, and the darker areas remain well-defined. Use the following images as a reference for adjusting exposure:
- Close the Histogram window when you are done with it.
Not seeing anything in the bottom camera feed?

If you are not seeing anything after adjusting the bottom camera exposure, ensure the lens caps on the bottom camera has been removed.

For Mac Users

On some Macs, If OpenPnP doesn’t allow exposure adjustments, use the open-source tool, CameraController.
Record the Bottom Camera Exposure Value
- OpenPnP may not retain camera settings after restart Record and save your exposure value by saving them in a text file or writing them down.
- This means every time you boot up OpenPnP you'll have to:
  - Toggle Auto Exposure on, then off. (This puts your camera into manual exposure mode)
  - Type your recorded exposure value into the exposure field beside the slider.
Apply and Save
- Click Apply in the lower right corner to save your changes, if applicable. (OpenPnP may have the button greyed out. That is fine.)
- Save your OpenPnP configuration now. File > Save Configuration.

Next Steps

Now that your LumenPnP V3 is connected, nozzle tips have been installed, and the bottom camera is configured, you're ready to proceed with Configuring Top Camera and Homing Fiducial.