text: #ifndef DELAY_H
  
  #define DELAY_H
  // about the default CPU frequency, see
  // https://stackoverflow.com/questions/34258254/msp430-delay-cycles-is-slow-mclk-might-be-slow
  // in order to make delay more accurate, set CPU frequency to 25MHz
  #define CPU_Freq            ((double)25000000)
  #define delay_us(x)         __delay_cycles((long)(CPU_Freq * (double)x / 1000000.0))
  #define delay_ms(x)         __delay_cycles((long)(CPU_Freq * (double)x / 1000.0))
  
  #endif
  