XLoBorg back in stock or similar product recommendation

First you want to create a limit for how close to exactly north/south you want to be matched and some variables to hold the results in before the loop:

tolerance = 5     # How many degrees from exact to match
isNorth = False
isSouth = False

Then in the loop after you have calculated the heading you want to check if the new heading is within the specified limits.

You can see if the previous loop was already pointing the same way to do an action once, or simply repeat the action for each loop while it is pointing that way.

    if (heading >= 360 - tolerance) or (heading <= 0 + tolerance):
        # Pointing north
        if not isNorth:
            # This runs once each time you start facing north
            print("North")
        # This runs each loop while pointing north
        isNorth = True
        isSouth = False
    elif (heading >= 180 - tolerance) and (heading <= 180 + tolerance):
        # Pointing south
        if not isSouth:
            # This runs once each time you start facing south
            print("South")
        # This runs each loop while pointing south
        isNorth = False
        isSouth = True
    else:
        # Not pointing at any of the above
        isNorth = False
        isSouth = False

The whole if (heading >= 360 - 5) or (heading <= 0 + 5): section needs to be indented so that it is within the while True: loop.

For example:

    heading = round(heading)
    
    if (heading >= 360 - 5) or (heading <= 0 + 5):
        # Pointing north
        if not isNorth:
            # This runs once each time you start facing north
            print("North")

Without the indentation this section is not being run during the loop, but after it ends. Since the loop never ends it is never run.

See https://www.askpython.com/python/python-indentation

There are different options depending on if you need to read the sensor at a regular interval, or just when you need an update.

As a starting point, this example adds UltraBorg readings to the Web UI: Diddiborg with Ultraborg over Web UI.

In that code the distances-once block takes the Ultrasonic readings and sends them back. The simplest thing would be to replace the code in this section so it performs a single read of the sensor and sends the result back.

Reading at a regular interval is a bit more work. In that case you would need to create a new thread in which your sensor reading code runs in its own loop. You can use a global value to pass the result back to the main thread. This time the distances-once section just needs to read the global result and send it back.

Very basic example with two threads sharing a global value: https://www.adamsmith.haus/python/answers/how-to-use-a-global-variable-w...