Hello Martin,
Your code worked! Today, I changed the line to the code that you suggested and set the altitude to -9; when the altitude readings changed up and down, the flaps opened and closed as intended.
I am going to try the library that you suggested in the earlier post too.
Do you think the DEV library that you created would be a better suit for my project goal? I am afraid I didn't understand too well about blocking functions vs non-blocking.
Thanks again for your time and your very helpful responses!