Changing setting of the UMSELn bits (for UART mode) and serial config values.

Before, the UMSELn1 bit was being to set to 1, putting the UART into a reserved mode. Now, we only set the high (0x80) bit to 1 for the ATmega8, which is needed to access UCSRnC (whose i/o address is shared with UBRRH).

Also, no longer bitwise-or the new config with the existing register value, because we're actually configuring all the settings in the register. (We're not using UCPOL, but it's supposed to be 0 in asynchronous mode.)

Author: damellis

hardware/arduino/cores/arduino/HardwareSerial.cpp

@@ -393,11 +393,11 @@ void HardwareSerial::begin(unsigned long baud, byte config)
   *_ubrrh = baud_setting >> 8;
   *_ubrrl = baud_setting;
 
-  //set number of data bits
-  current_config = *_ubrrh;
-  current_config = *_ucsrc;
-  current_config |= config;
-  *_ucsrc = current_config;
+  //set the data bits, parity, and stop bits
+#if defined(__AVR_ATmega8__)
+  config |= 0x80; // select UCSRC register (shared with UBRRH)
+#endif
+  *_ucsrc = config;
 
   sbi(*_ucsrb, _rxen);
   sbi(*_ucsrb, _txen);

hardware/arduino/cores/arduino/HardwareSerial.h

@@ -69,30 +69,30 @@ class HardwareSerial : public Stream
 };
 
 // Define config for Serial.begin(baud, config);
-#define SERIAL_5N1 0x80
-#define SERIAL_6N1 0x82
-#define SERIAL_7N1 0x84
-#define SERIAL_8N1 0x86
-#define SERIAL_5N2 0x88
-#define SERIAL_6N2 0x8A
-#define SERIAL_7N2 0x8C
-#define SERIAL_8N2 0x8E
-#define SERIAL_5E1 0xA0
-#define SERIAL_6E1 0xA2
-#define SERIAL_7E1 0xA4
-#define SERIAL_8E1 0xA6
-#define SERIAL_5E2 0xA8
-#define SERIAL_6E2 0xAA
-#define SERIAL_7E2 0xAC
-#define SERIAL_8E2 0xAE
-#define SERIAL_5O1 0xB0
-#define SERIAL_6O1 0xB2
-#define SERIAL_7O1 0xB4
-#define SERIAL_8O1 0xB6
-#define SERIAL_5O2 0xB8
-#define SERIAL_6O2 0xBA
-#define SERIAL_7O2 0xBC
-#define SERIAL_8O2 0xBE
+#define SERIAL_5N1 0x00
+#define SERIAL_6N1 0x02
+#define SERIAL_7N1 0x04
+#define SERIAL_8N1 0x06
+#define SERIAL_5N2 0x08
+#define SERIAL_6N2 0x0A
+#define SERIAL_7N2 0x0C
+#define SERIAL_8N2 0x0E
+#define SERIAL_5E1 0x20
+#define SERIAL_6E1 0x22
+#define SERIAL_7E1 0x24
+#define SERIAL_8E1 0x26
+#define SERIAL_5E2 0x28
+#define SERIAL_6E2 0x2A
+#define SERIAL_7E2 0x2C
+#define SERIAL_8E2 0x2E
+#define SERIAL_5O1 0x30
+#define SERIAL_6O1 0x32
+#define SERIAL_7O1 0x34
+#define SERIAL_8O1 0x36
+#define SERIAL_5O2 0x38
+#define SERIAL_6O2 0x3A
+#define SERIAL_7O2 0x3C
+#define SERIAL_8O2 0x3E
 
 #if defined(UBRRH) || defined(UBRR0H)
   extern HardwareSerial Serial;