/* based on example from https://github.com/satoshinm/pill_blink */ #include "bluepill.h" #define LED_PIN 13 static inline void delay(unsigned long ms) { for (unsigned long i = 0; i < ms; ++i) __asm__("nop"); } static inline void led_off() { clear_pin(GPIO_C, LED_PIN); } static inline void led_on() { set_pin(GPIO_C, LED_PIN); } int main(void) { *RCC |= (1 << 4); /* enable port C clock */ output_mode(GPIO_C, LED_PIN, OUTPUT_GPP, OUTPUT_MAX_2MHZ); while(1) { led_off(); delay(1000000); led_on(); delay(100000); led_off(); delay(100000); led_on(); delay(100000); } }