Important! You must also download and install several Arduino libraries, required by the sketches in this installment. These libraries are provided in Lesson 3, so if you’ve been following along in this series, you should already have them. This lesson does not require any additional libraries other than those provided for in Lesson 3.
This is a companion discussion topic for the original entry at https://community.robotshop.com/index.php/blog/show/arduino-powered-desktop-pal-lesson-4-adding-stereo-ultrasonic-vision-and-passive-infrared-sensing