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Diffstat (limited to 'cores/arduino/wiring_serial.c')
| -rwxr-xr-x | cores/arduino/wiring_serial.c | 212 |
1 files changed, 212 insertions, 0 deletions
diff --git a/cores/arduino/wiring_serial.c b/cores/arduino/wiring_serial.c new file mode 100755 index 0000000..9392a09 --- /dev/null +++ b/cores/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); +} +*/ |