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authorDavid A. Mellis <d.mellis@arduino.cc>2007-10-06 13:02:43 +0000
committerDavid A. Mellis <d.mellis@arduino.cc>2007-10-06 13:02:43 +0000
commit179fcdbda432ff33a921a70994087b08b2a79caa (patch)
treedb62b71d303b5b13876773552451406b13cc66cf /core/arduino/wiring_serial.c
Moving things around - creating the hardware directory and sticking all the avr code, etc. in there.
Diffstat (limited to 'core/arduino/wiring_serial.c')
-rwxr-xr-xcore/arduino/wiring_serial.c212
1 files changed, 212 insertions, 0 deletions
diff --git a/core/arduino/wiring_serial.c b/core/arduino/wiring_serial.c
new file mode 100755
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--- /dev/null
+++ b/core/arduino/wiring_serial.c
@@ -0,0 +1,212 @@
+/*
+ wiring_serial.c - serial functions.
+ Part of Arduino - http://www.arduino.cc/
+
+ Copyright (c) 2005-2006 David A. Mellis
+
+ This library is free software; you can redistribute it and/or
+ modify it under the terms of the GNU Lesser General Public
+ License as published by the Free Software Foundation; either
+ version 2.1 of the License, or (at your option) any later version.
+
+ This library is distributed in the hope that it will be useful,
+ but WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ Lesser General Public License for more details.
+
+ You should have received a copy of the GNU Lesser General
+ Public License along with this library; if not, write to the
+ Free Software Foundation, Inc., 59 Temple Place, Suite 330,
+ Boston, MA 02111-1307 USA
+
+ $Id: wiring.c 248 2007-02-03 15:36:30Z mellis $
+*/
+
+#include "wiring_private.h"
+
+// Define constants and variables for buffering incoming serial data. We're
+// using a ring buffer (I think), in which rx_buffer_head is the index of the
+// location to which to write the next incoming character and rx_buffer_tail
+// is the index of the location from which to read.
+#define RX_BUFFER_SIZE 128
+
+unsigned char rx_buffer[RX_BUFFER_SIZE];
+
+int rx_buffer_head = 0;
+int rx_buffer_tail = 0;
+
+void beginSerial(long baud)
+{
+#if defined(__AVR_ATmega168__)
+ UBRR0H = ((F_CPU / 16 + baud / 2) / baud - 1) >> 8;
+ UBRR0L = ((F_CPU / 16 + baud / 2) / baud - 1);
+
+ // enable rx and tx
+ sbi(UCSR0B, RXEN0);
+ sbi(UCSR0B, TXEN0);
+
+ // enable interrupt on complete reception of a byte
+ sbi(UCSR0B, RXCIE0);
+#else
+ UBRRH = ((F_CPU / 16 + baud / 2) / baud - 1) >> 8;
+ UBRRL = ((F_CPU / 16 + baud / 2) / baud - 1);
+
+ // enable rx and tx
+ sbi(UCSRB, RXEN);
+ sbi(UCSRB, TXEN);
+
+ // enable interrupt on complete reception of a byte
+ sbi(UCSRB, RXCIE);
+#endif
+
+ // defaults to 8-bit, no parity, 1 stop bit
+}
+
+void serialWrite(unsigned char c)
+{
+#if defined(__AVR_ATmega168__)
+ while (!(UCSR0A & (1 << UDRE0)))
+ ;
+
+ UDR0 = c;
+#else
+ while (!(UCSRA & (1 << UDRE)))
+ ;
+
+ UDR = c;
+#endif
+}
+
+int serialAvailable()
+{
+ return (RX_BUFFER_SIZE + rx_buffer_head - rx_buffer_tail) % RX_BUFFER_SIZE;
+}
+
+int serialRead()
+{
+ // if the head isn't ahead of the tail, we don't have any characters
+ if (rx_buffer_head == rx_buffer_tail) {
+ return -1;
+ } else {
+ unsigned char c = rx_buffer[rx_buffer_tail];
+ rx_buffer_tail = (rx_buffer_tail + 1) % RX_BUFFER_SIZE;
+ return c;
+ }
+}
+
+void serialFlush()
+{
+ // don't reverse this or there may be problems if the RX interrupt
+ // occurs after reading the value of rx_buffer_head but before writing
+ // the value to rx_buffer_tail; the previous value of rx_buffer_head
+ // may be written to rx_buffer_tail, making it appear as if the buffer
+ // were full, not empty.
+ rx_buffer_head = rx_buffer_tail;
+}
+
+#if defined(__AVR_ATmega168__)
+SIGNAL(SIG_USART_RECV)
+#else
+SIGNAL(SIG_UART_RECV)
+#endif
+{
+#if defined(__AVR_ATmega168__)
+ unsigned char c = UDR0;
+#else
+ unsigned char c = UDR;
+#endif
+
+ int i = (rx_buffer_head + 1) % RX_BUFFER_SIZE;
+
+ // if we should be storing the received character into the location
+ // just before the tail (meaning that the head would advance to the
+ // current location of the tail), we're about to overflow the buffer
+ // and so we don't write the character or advance the head.
+ if (i != rx_buffer_tail) {
+ rx_buffer[rx_buffer_head] = c;
+ rx_buffer_head = i;
+ }
+}
+
+void printMode(int mode)
+{
+ // do nothing, we only support serial printing, not lcd.
+}
+
+void printByte(unsigned char c)
+{
+ serialWrite(c);
+}
+
+void printNewline()
+{
+ printByte('\n');
+}
+
+void printString(const char *s)
+{
+ while (*s)
+ printByte(*s++);
+}
+
+void printIntegerInBase(unsigned long n, unsigned long base)
+{
+ unsigned char buf[8 * sizeof(long)]; // Assumes 8-bit chars.
+ unsigned long i = 0;
+
+ if (n == 0) {
+ printByte('0');
+ return;
+ }
+
+ while (n > 0) {
+ buf[i++] = n % base;
+ n /= base;
+ }
+
+ for (; i > 0; i--)
+ printByte(buf[i - 1] < 10 ?
+ '0' + buf[i - 1] :
+ 'A' + buf[i - 1] - 10);
+}
+
+void printInteger(long n)
+{
+ if (n < 0) {
+ printByte('-');
+ n = -n;
+ }
+
+ printIntegerInBase(n, 10);
+}
+
+void printHex(unsigned long n)
+{
+ printIntegerInBase(n, 16);
+}
+
+void printOctal(unsigned long n)
+{
+ printIntegerInBase(n, 8);
+}
+
+void printBinary(unsigned long n)
+{
+ printIntegerInBase(n, 2);
+}
+
+/* Including print() adds approximately 1500 bytes to the binary size,
+ * so we replace it with the smaller and less-confusing printString(),
+ * printInteger(), etc.
+void print(const char *format, ...)
+{
+ char buf[256];
+ va_list ap;
+
+ va_start(ap, format);
+ vsnprintf(buf, 256, format, ap);
+ va_end(ap);
+
+ printString(buf);
+}
+*/