Introduction to Sensors What are sensors Your answers

Introduction to Sensors

What are sensors? • Your answers here!

What are sensors? • A sensor tells a robot one simple thing about it’s environment – Temperature – Distance – Light intensity • Allow robots to see and feel the physical world through which they travel • Two main types of sensors: digital and analog

Analog Sensors • Can provide a range of feedback • The robot will interpret feedback from the sensor as a number from 0 to a predefined maximum (1024 for most Vex sensors) • A light sensor has many states: – If it is very bright, the sensor will return a number close to 30 – If it is very dark, the sensor will return a number close to 1000

Digital Sensors • Can distinguish between two different “states” • The meaning of the states depends on the sensor • A bumper sensor has two “states” – If it is pressed, it is a 0 – If it is not pressed, it is a 1

Variables • A value-holding “container” with a label • You can retrieve the value in this “container” when it is needed » There are different types of values you can store in variables. » You will use the “int” type, which allows you to store any whole number from 0 to a large number (positive or negative) » You can assign a starting value to your variable which will store that value at the start of the program

Bump Sensor Introduction • Open the project “BUMPERTEST. ECP” • Download it to your robot and open the terminal window

Understanding bump sensor code • Comments - allows you to leave notes to yourself and others about your code • The compiler ignores comments

Understanding bump sensor code • While Loop – block of code that repeats itself as long as the condition inside the parenthesis is true – The == operator returns true if both sides are equal, and false if they are not equal – In our code loop will always equal 1, so this loop will run forever

Understanding bump sensor code • Bumper sensor – stores the value of the digital input 6 to the variable “bumper” – Now the robot knows if the bump sensor is being pressed in (0) or not (1)

Understanding bump sensor code • Print to screen – displays information in the terminal window – This particular code displays the value of the bump sensor For now, make sure your settings are as follows: * Directive: %d * Type-cast: int * Variable: the variable you want to display * Message: the message with the variable

Writing your own code • We are going to write a program that runs one motor until a bump sensor is pressed in • Begin by opening easy. C