Waveshare Infrared Proximity Sensor, Obstacle Avoiding

Obstacle avoidance is one of the most basic requirements for any wheeled or walking robot, and this sensor handles exactly that job - emitting infrared and reading the reflection to detect whether something solid is in range ahead of it, without needing the complexity of a full distance-ranging sensor when a simple presence/absence detection is all the application calls for. Straightforward and inexpensive, it's the sensor to reach for when a robotics build just needs to know 'is something in my way' rather than exactly how far away that something is.