some new functions to make the obstacle avoidng car

pulseIn()

##definition

• Reads a pulse (either HIGH or LOW) on a pin. For example, if value is HIGH, pulseIn() waits for the pin to go from LOW to HIGH, starts timing, then waits for the pin to go LOW and stops timing.

  (account the time of HIGH mode)

• it will return the length of the pulse

  data type: unsigned long

Syntax

pulesIn(pin, value, timeout);

#define

##definition

• #define allows the programmer to give a name to a constant value before the program is compiled.
• const is better than #define, it should replace #define.

syntax

#define constantName value

warning

there is no ; after the code

#inculde

##definition

• #include allows you to use outside libraries in your code.
• the main reference page for arduino in here.

syntax

#include <Servo.h>

##warning
there is no ; after the code