I just spend a day on a annoying problem.
I had a code that was working with a Arduino Due and a SIM808 GSM modul, using THINGER_TINY_GSM libary.
I compiled the code for a teensy LC and it worked right out of the box.
Then I switched to a Teensy 3.2 and nothing was working. The debug out put stoped at “Can’t connect to APN!”
After checking powersupply, changing GSM Modul etc, I noticed a option in the arduino IDE when the teensy drivers are installed: Their are optimization settings for the code: fast, faster, fastest, debug and smallest code.
I never touched this settings and it was set to “faster”. When I changed it to debug everything worked. Later I checked if it also works for the other settings and noticed that I only experienced the problem with the standart settings “faster”.
Perhaps this post will save somebody one day!
But nevertheless I still love this thinger project.