Follow the steps below to measure and view the results using the RoboCap app.
Measuring Sampson Error
If you're checking the Sampson Error for the first time, you'll need to download RoboCap's original factory calibration data before measuring (Steps 5-6). This one-time setup takes less than 5 minutes.
For future measurements, you can skip Steps 5–6.
Step 1: Check RoboCap Firmware
Before starting, make sure RoboCap is running the latest firmware.
If an update is needed, follow our How to Update RoboCap Firmware guide.
Step 2: Turn On RoboCap
Using the provided USB-C cable, connect RoboCap's rear USB-C power port to a power bank with a 5V/3A (15W) output.
Slide the Power Switch from O (OFF) to I (ON) to turn on RoboCap.
Wait for RoboCap to finish starting up. The green indicator light will turn on when RoboCap is ready.
Step 3: Connect to RoboCap
Step 4: Connect to RoboCap's Wi-Fi
Open your phone's Wi-Fi settings.
Select RoboCap's Wi-Fi network (
Robocap_xxx).Enter the default password:
12345678.Wait for your phone to connect.
Step 5: Connect RoboCap to the Internet (One-time only)
RoboCap needs an internet connection to download the factory calibration data.
In the RoboCap app, tap More → Wi-Fi setup.
Scroll down to Configure WiFi.
Under Network, select a Wi-Fi network with internet access, such as your home or office Wi-Fi.
Enter the network password.
Tap Connect to [network name].
Wait until Current connection displays Connected, along with the network name and IP address.
Note: This connects RoboCap itself to the internet, which is different from connecting your phone to RoboCap's Wi-Fi (Robocap_xxx).
Step 6: Download and Install the Calibration Data (One-time only)
Return to the Calibration tab.
Select Recalibrate.
Scroll down to Factory calibration.
Tap Check the server.
Tap Download to install the factory calibration data.
Wait until the installation finishes.
Confirm that Installed on this device displays v1.
Step 7: Open Sampson Error
Tap Sampson error button next to Recalibrate.
Click Measure now
Step 8: Measure the Sampson Epipolar Error
Follow the preparation instructions displayed in the app.
Wear RoboCap securely on your head.
Face a well-lit environment with plenty of visible objects and details. Avoid reflective surfaces such as mirrors and glass windows.
Make sure no cameras are blocked.
Watch the measurement progress displayed in the app.
The target is 10 still pictures for the front cameras and 10 for the eye cameras.
Tap Start measuring.
Keep your head still until the measurement is complete. This process will take up to 2 minutes.
Step 9: View the Results
Once the measurement is complete, the Sampson Epipolar Error results will appear in the app.
You can review the measurements for both the front camera pair and eye camera pair.
Step 10: Export Sampson Error Results
You can export your Sampson Error measurement history by email or download it directly to your phone.
In the RoboCap app, tap Calibration in the bottom menu.
Open Sampson Error and scroll down to Export Report History.
Choose one of the following options:
Send by Email
Tap Email to open your phone's email app.
Enter the recipient's email address and send the email.
Download to Phone
Select the download option to save the report directly to your mobile phone.
Measuring Sampson Error Again
If you've already completed the initial setup, you can measure the Sampson Error again without downloading the factory calibration data.
Follow the same process starting with Turn On RoboCap, then proceed directly to Open Calibration, Prepare for Measurement, and Start Measuring.
Skip the factory calibration download steps.
If Your Measurement Doesn't Produce Results
If the app reports that RoboCap was not held still enough:
Make sure RoboCap is securely positioned on your head.
Keep your head still throughout the measurement.
Ensure the cameras are not blocked.
Face a well-lit environment with visible objects and details.
Tap Measure now to try again.