_From @rogerclarkmelbourne on November 20, 2016 21:11_ In various lines Winterrupts.c e.g. https://github.com/stm32duino/Arduino_Core_STM32L4/blob/master/cores/arduino/WInterrupts.c#L43 .configured is written but never read. These lines can be removed and `PinDescription g_intPinConfigured[MAX_DIGITAL_IOS];` can be changed to a array of pointers to PinDescription (and the code changed accordingly) _Copied from original issue: stm32duino/Arduino_Core_STM32L4#4_