Altered range to send values from 110 Hz (A below low C) to 621 Hz (D above high C). The python script will have to convert these frequencies into note keys and note names.

project/main.c

@@ -2,6 +2,7 @@
 
 #define   TXD       BIT2
 #define   RXD       BIT1
+#define   LED       BIT0
 
 #define   US        1000000
 
@@ -22,26 +23,21 @@ void main(void) {
   UCA0MCTL  = UCBRS0;           // Modulation UCBRSx = 1
   UCA0CTL1 &= ~UCSWRST;         // Initialize USCI state machine
 
-  P1DIR    |= TXD;
+  P1DIR    |= TXD | LED;
   P1OUT    |= TXD;
 
-  P1DIR |= BIT0;
-
   TACTL     = TACLR;            // reset clock
   TACTL     = TASSEL_2 | MC_2;  // set SMCLK timer to count up at 1 MHz
   TACCTL0   = CM1 | SCS | CAP | CCIE;   // set capture mode to rising edge and enable interrupts
   
   while (1) {
     TAR = 0;
-    P1OUT ^= BIT0;
+    P1OUT ^= LED;
     __enable_interrupt();
     __bis_SR_register(LPM0_bits + GIE);
-    TXByte = US/TACCR0;                 // frequency in Hz
-    
-    TXByte /= 2;                        // frequency won't fit in a byte
+    TXByte = US/TACCR0;                 // frequency in Hertz
     while (!(IFG2 & UCA0TXIFG));        // wait for TX buffer to be ready for new data
-    UCA0TXBUF = TXByte;           
-
+    UCA0TXBUF = (TXByte - 110)/2;       // send range of 110 Hz (A below low C) to 621 Hz (D above high C)
     __delay_cycles(100000);             // wait >10 ms before measuring again
   }
 }