text: #ifndef USART1_H
  #define USART1_H
  
  #include <stdint.h>
  #include "stm32f1xx.h"
  
  #ifdef __cplusplus
  extern "C" {
  #endif
  
  void usart1Init();
  void usart1WriteChar(char c);
  void usart1WriteString(const char *str);
  void usart1DumpHex(uint32_t v);
  static inline uint32_t usart1Ready() {return USART1->SR & USART_SR_TXE;}
  
  #ifdef __cplusplus
  }
  #endif
  
  #endif // USART1_H
  