Software Setup

Open the VSCode from the Applications directory on the flash drive
Click on the small green square in the bottom left corner of the screen
Select the “Connect Current Window to Host…” option
Type “pi@pibot##” and press enter

Replace the text “pibot##” with the label on the pibot

The password to enter when prompted is “DogsAndCatsAreNice2.” without the quotes. The '.' at the end is important!

It may take a couple of minutes while it installs some files on the PiBot
Click the “Open Folder” button
Select the “pibot” folder and click the “OK” button
Select the picar-line-maze.py file in the list on the left
Select File→Save As… and save the file as picar-line-maze-obstacles.py
Use the information below to change the code so that the PiBot will solve the maze with obstacles
After the changes to the code are complete, save it with File→Save

Software Explanation

Copy the GPIO settings for the ECHO and TRIGGER pins as well as the servo setting from the picar-obstacle-avoid.py file
Copy the measure function from the picar-obstacle-avoid.py file
Copy the pwm.set_pwm function calls for the servo from the picar-obstacle-avoid.py file
Copy the ob_range variable from the picar-obstacle-avoid.py file and use it to determine if there is an obstacle that the PiBot needs to avoid
Include debugging prints to help troubleshoot if the distance measured doesn't seem to be working
Make the changes to the intersection decision logic to sense for obstacles and react to any obstacles that are in the path

It may be easiest to only take a sonar measurement after making a decision (and turn if necessary) at an intersection. If there is an obstacle then the PiBot will need to undo the decision (and turn).
Bonus points if you include moving the sonar sensor in the PiBot's “Happy Dance” when it reaches the end of the maze

"Do you see a man skillful in his work? He will stand before kings; he will not stand before obscure men. - Proverbs 22:29"