#include "WProgram.h" extern "C" int main(void) { #if !defined(ARDUINO) // To use Teensy 3.0 without Arduino, simply put your code here. // For example: pinMode(13, OUTPUT); while (1) { digitalWriteFast(13, HIGH); delay(500); digitalWriteFast(13, LOW); delay(500); } #else // Arduino's main() function just calls setup() and loop().... setup(); while (1) { loop(); yield(); } #endif }