serial_ascii_binary app: A few changes to the comments to make it mor…

…e clear which interface is for ASCII and which is for binary for someone who just wants the information fast. Also fixed the conversion to lower case so it is only done in the correct place. Also got rid of unused static variables.

apps/serial_ascii_binary/serial_ascii_binary.c

@@ -1,27 +1,27 @@
 /* serial_ascii_binary app:
- * This app enables your wixel to convert between hex ASCII characters
- * and binary byte data using the interfaces UART0 and UART1.
+ * This app enables your Wixel to convert between hex ASCII characters
+ * and raw binary byte data using the interfaces UART0 and UART1.
  *
  * The flow of bidirectional information can be described as:
  * binary byte data -> UART1 -> converted into ASCII hex digits -> UART0 -> ASCII hex digits
- * ASCII hex digit -> UART0 -> converted into binary byte data -> UART1 -> binary byte data
+ * ASCII hex digits -> UART0 -> converted into binary byte data -> UART1 -> binary byte data
  *
- * When sending ASCII HEX data to UART0, to signal the start of a data stream, send
- * the delimiting character 'H' first, and then proceed to send your ASCII hex
- * characters.
+ * When sending ASCII hex data to UART0, to signal the start of a data stream, send
+ * the delimiting character 'H' first, and then proceed to send an even number
+ * of hex digits.
  *
- * Example input on UART0:  'H','1','F','A','3'
- * Example output on UART1: 0x1F,0xA3
+ * Example ASCII input on UART0:   'H','1','F','A','3'
+ * Example binary output on UART1: 0x1F,0xA3
  *
- * Example input on UART1:  0xA2,0x35
- * Example output on UART0: 'H','A','2','H','3','5'
+ * Example ASCII input on UART1:   0xA2,0x35
+ * Example binary output on UART0: 'H','A','2','H','3','5'
  *
- * For UART0, the following pins are used:
+ * For UART0, the ASCII interface, the following pins are used:
  *
  * P0_3: TX
  * P0_2: RX
  *
- * For UART1, the following pins are used:
+ * For UART1, the binary interface, the following pins are used:
  * P1_6: TX
  * P1_7: RX
  *
@@ -37,15 +37,15 @@
 #define IS_HEX_DIGIT(byte)(((byte) >= 'a' && (byte) <= 'f') || ((byte) >= '0' && (byte) <= '9'))
 
 
-/** Parameters *********************************************************************************/
+/** Parameters ****************************************************************/
 
 // Set UART0 baud rate.
 int32 CODE param_ascii_baud_rate = 9600;
 
 // Set UART1 baud rate. 
 int32 CODE param_binary_baud_rate = 9600;
 
-/** Funcions **********************************************************************************/
+/** Functions *****************************************************************/
 
 uint8 hexDigitToNibble(uint8 digit)
 {
@@ -81,11 +81,9 @@ void asciiToBinaryService()
     // Receive ASCII hex on UART0. Send bytes on UART1.
     while(uart0RxAvailable() && uart1TxAvailable())
     {
-        // If we get a hex letter we convert it to lower case.
-        uint8 byte = uart0RxReceiveByte() | 0x20;
+        uint8 byte = uart0RxReceiveByte();
         if (IS_HEX_DIGIT(byte))
         {
-            // Bounds check.
             if(count == 0)
             {
                 firstHexDigit = byte;
@@ -108,9 +106,6 @@ void asciiToBinaryService()
 // The first byte received is assumed to be the most significant byte. 
 void binaryToAsciiService()
 {
-    static uint8 count = 0;
-    static uint8 firstHexDigit = 0;
-
     while(uart1RxAvailable() && uart0TxAvailable() >= 3)
     {
         uint8 byte = uart1RxReceiveByte();