Why isn't my Finch Robot 1 detecting an obstacle?

The Finch 1 uses two infrared LEDs and an infrared receiver to detect obstacles. Using infrared is a low-cost and effective way to detect most obstacles, but it is limited. We strongly recommend using lightly colored obstacles like cardboard boxes or white office paper. Covering obstacles in tin foil increases responsiveness significantly.

Additionally:

• The obstacle must be approximately 2”-4” from the sensor to be detected.
• Dark and non-reflective objects are harder to detect.
• Narrow vertical objects like chair legs may not be detected.
• Certain black plastics transmit infrared light (they look like glass in the IR spectrum) and don’t reflect sufficiently to be detected.