Adds better default parameter definitions to Serial Transport

Change-type: minor
Signed-off-by: Alex Bucknall <[email protected]>

notecard/main.go

@@ -16,7 +16,8 @@ const (
 	I2C    = "i2c"
 )
 
-const SerialDevice = "/dev/tty.usbmodemNOTE1"
+const defaultSerialDevice = "/dev/tty.usbmodemNOTE1"
+const defaultSerialBaud = "9600"
 
 type server struct {
 	card      *notecard.Context
@@ -88,9 +89,9 @@ func setupNotecard(protocol string) (*notecard.Context, error) {
 	}
 
 	if protocol == Serial {
-		serialPort := getEnv("NOTECARD_SERIAL_DEVICE", SerialDevice)
+		serialPort := getEnv("NOTECARD_SERIAL_DEVICE", defaultSerialDevice)
 
-		baud, err := strconv.Atoi(getEnv("NOTECARD_SERIAL_BAUD", "9600"))
+		baud, err := strconv.Atoi(getEnv("NOTECARD_SERIAL_BAUD", defaultSerialBaud))
 		if err != nil {
 			return nil, fmt.Errorf("error parsing NOTECARD_SERIAL_BAUD: %v", err)
 		}