Passive Infra-Red (PIR) sensors are used to detect motion based on the infrared heat in the surrounding area. This makes them a popular choice when building a system to detect potential intruders or people in general. These sensors can take for 10-60 seconds to warm up, so try to avoid motion during that time.
Basic motion detection.
The H8054 PIR motion detection module provides basic motion detection in a small package. Compatible with the Arduino and Raspberry Pi
This is a very small light sensor. A photo resistor (also known as a photodector, or photocell) changes resistance depending on the amount of light it is exposed to.
2WD self balancing robot! This kit is a perfect plataform for learning Arduino, PID control, serial communications(Serial, I2C, SPI), PWM signals, IMU filtering, etc.
This is a direct drive 4WD base Programmable robot kit that uses Nexus mecanum wheels. It is an Arduino robot platform for indoor robotics. It can vector in any direction. Includes a choice of Arduino for making a great Autonomous Robot.