Unit 02 · lesson

Typed Sensor Evidence Is More Than a Java Type

This bridge assumes you already know Java primitives, variables, strings, and expressions.

The bridge question is different: what does a sensor value mean, and what evidence supports that meaning?

Use a value such as 0.42 and identify four separate facts:

representation: double
unit: meters
source: local Java state or ROS message field
claim: what this value can actually support

A Java variable named frontRangeMeters is JVM evidence. A sensor_msgs/msg/Range message is ROS runtime evidence. Equal numbers do not prove one produced the other.

Checkpoint

Given one Java value and one ROS message field, record the type, unit, source, timestamp/context if available, and one claim that remains unsupported.

If Java type mechanics are the blocker, return to java-programming before continuing.