FastLED freezes program with Teensyduino 1.59.0



I recently recompiled a mature, working program for a Teensy 3.5, using Arduino IDE 2.3.2 and Teensyduino 1.59.0. It had last been compiled about two years ago, on whatever were the latest versions at that time. While it did compile ok, I found that the program would immediately freeze. I was able to determine that the FastLED 'addLeds' instruction was the culprit.

I tried a few things: First, eliminating the 'addLeds' and other FastLED instructions allows the program to run. Then I compared the code against the FastLED examples (looks good) and tried a number of FastLED library versions, all to no avail. Then I changed Teensyduino from 1.59.0 to 1.58.2, and the issue resolved itself. I do see in the 1.59.0 release notes the comment "FastLED fix C++17 compiler warnings", so I expect a bug was introduced with this version.

Please let me know if you have any questions!