I saved your requirements in IR Sensor Array Requirements: 16 IR reflectance sensors arranged in an arc for a fast line-following robot. No components or PCB layout have been created yet; the next inputs needed are sensing width, arc depth, and sensor height above the track.
Sensor research and PCB design require Agent mode. Execution stopped because your ACUs ran out.
What is Agent mode?
Agent mode lets Flux build, do deep research, validate designs, and work through complex assignments.
Chat mode is just as smart and has the same engineering knowledge, but it cannot work autonomously.
Only Agent mode consumes your plan's included AI usage (measured in ACUs).