hmmm... I think it would be wise to create a boolean and to check if its still the same, right?
Something like that, yes. You need to Compare the current value to the threshold. If above, print the value (if the above flag is false), set the above flag to true, and set the below flag to false.
If below, print the value (if the below flag is false), set the below flag to true, and set the above flag to false.
What should the sketch look like?
I'm sure that you can figure it out. Or, you go first. Post your code.