write a code of arduino uno , with:

trigger , A1

echo, A0

Line Follower Robot - Design and implement a line follower robot using an Arduino microcontroller. - The robot should follow the track accurately and stay at a 20cm away from obstacles placed on the track. - If the obstacle draws nearer to the robot, it should back track to keep the distance. If it is moved away, it should follow it. - The system mainly includes a line follower sensor array, an Arduino microcontroller, and an ultrasonic /I Motor A connections int enA =5; int in1 =2; int in2 =4; I/ Motor B connections int enB =10; int in3 =7; int in4 =8