08 / OpenCV and AprilTags

VisionPortal Camera Setup

Create a camera pipeline that can stream, process, and report telemetry.

60 minVisionOpenCV and AprilTags

You will

01Explain the role of VisionPortal.
02Attach processors to a camera stream.
03Show processor outputs through telemetry and Dashboard stream.

Why VisionPortal Camera Setup matters

This lesson is about turning camera images into trustworthy robot decisions. The goal is not to make vision seem magical; it is to show how camera setup, processor output, telemetry, and fallbacks make an autonomous decision safe enough to use.

Starting point

VisionPortal owns the camera session

The modern FTC SDK vision stack uses VisionPortal to manage camera opening, streaming, and processors. Students should learn the lifecycle before writing image math.

Streaming is a debugging tool

A camera stream lets teams see what the robot sees. The centerstage code includes stream processors for Dashboard, which is a strong habit for event debugging.

Build path

Start with a visible stream and raw telemetry before making decisions. Then add regions, detections, metadata, or pose estimates. Autonomous should receive a simple result and confidence, not a pile of image-processing details.

For this specific lesson, students should first restate the goal in robot terms, then identify the value or behavior they expect to observe, then run the smallest test that proves the idea. The lesson should feel like a guided lab: predict, run, observe, explain, and only then extend.

VisionPortalSetup.java · Java

AprilTagProcessor aprilTags = new AprilTagProcessor.Builder().build();

VisionPortal portal = new VisionPortal.Builder()
        .setCamera(hardwareMap.get(WebcamName.class, "Webcam 1"))
        .addProcessor(aprilTags)
        .build();

while (opModeIsActive()) {
    telemetry.addData("Portal state", portal.getCameraState());
    telemetry.addData("Tag count", aprilTags.getDetections().size());
    telemetry.update();
}

Debugging and failure modes

Vision fails through lighting, camera placement, exposure, cable issues, wrong tag assumptions, and thresholds that only worked in the shop. The debugging habit is to show the image, print raw scores or detections, and define a safe fallback when the robot is not confident.

Checks

The camera opens without blocking match start.
Telemetry shows camera state.
The team can see the camera stream while testing.

Check your understanding

Module check

What manages camera streaming and vision processors in the current FTC SDK?

0 of 1 answered

References

FTC VisionPortal DocsOfficial VisionPortal overview and examples.FIRST FTC DocsOfficial FTC SDK and robot programming documentation.Game Manual 0Community FTC programming, control, and robot design reference.