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/**
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* Copyright (c) 2007 Colony Project
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*
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* Permission is hereby granted, free of charge, to any person
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* obtaining a copy of this software and associated documentation
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* files (the "Software"), to deal in the Software without
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* restriction, including without limitation the rights to use,
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* copy, modify, merge, publish, distribute, sublicense, and/or sell
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* copies of the Software, and to permit persons to whom the
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* Software is furnished to do so, subject to the following
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* conditions:
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*
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* The above copyright notice and this permission notice shall be
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* included in all copies or substantial portions of the Software.
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*
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* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
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* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES
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* OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
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* NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT
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* HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
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* WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
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* FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
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* OTHER DEALINGS IN THE SOFTWARE.
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**/
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/**
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* @file xbee.c
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* @brief XBee Interface
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*
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* Implementation of low level communication with the XBee in API mode.
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*
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* @author Brian Coltin, Colony Project, CMU Robotics Club
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**/
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#include <xbee.h>
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#include <wl_defs.h>
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#define ROBOT
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#define WL_DEBUG
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#define WL_DEBUG_PRINT( s ) usb_puts( s )
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#define WL_DEBUG_PRINT_INT( i ) usb_puti(i)
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#ifndef ROBOT
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#include <fcntl.h>
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#include <unistd.h>
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#include <pthread.h>
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#include <errno.h>
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#include <termios.h>
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#else
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#include <serial.h>
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#include <avr/interrupt.h>
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#endif
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#include <stdio.h>
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#include <stdlib.h>
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#include <string.h>
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#define XBEE_FRAME_START 0x7E
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#define XBEE_GET_PACKET_TIMEOUT 1000
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/*Frame Types*/
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#define XBEE_FRAME_STATUS 0x8A
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#define XBEE_FRAME_AT_COMMAND 0x08
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#define XBEE_FRAME_AT_COMMAND_RESPONSE 0x88
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#define XBEE_FRAME_TX_REQUEST_64 0x00
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#define XBEE_FRAME_TX_REQUEST_16 0x01
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#define XBEE_FRAME_TX_STATUS XBEE_TX_STATUS
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#define XBEE_FRAME_RX_64 0x80
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#define XBEE_FRAME_RX_16 XBEE_RX
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/*Internal Function Prototypes*/
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/*I/O Functions*/
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static int xbee_send(char* buf, int size);
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static int xbee_send_string(char* c);
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#ifndef ROBOT
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static int xbee_read(char* buf, int size);
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#endif
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/*Command Mode Functions
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* Called during initialization.
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*/
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static int xbee_enter_command_mode(void);
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static int xbee_exit_command_mode(void);
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static int xbee_enter_api_mode(void);
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static int xbee_wait_for_string(char* s, int len);
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static int xbee_wait_for_ok(void);
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/*API Mode Functions*/
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static int xbee_handle_packet(char* packet, int len);
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static void xbee_handle_at_command_response(char* command, char result, char* extra, int extraLen);
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static void xbee_handle_status(char status);
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static int xbee_verify_checksum(char* packet, int len);
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static char xbee_compute_checksum(char* packet, int len);
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static int xbee_send_frame(char* buf, int len);
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int xbee_send_read_at_command(char* command);
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static int xbee_send_modify_at_command(char* command, char* value);
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/*Global Variables*/
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#ifndef ROBOT
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static char* xbee_com_port = XBEE_PORT_DEFAULT;
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static int xbee_stream;
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static pthread_t* xbee_listen_thread;
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#endif
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// TODO: is this a good size?
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#define XBEE_BUFFER_SIZE 128
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#define PACKET_BUFFER_SIZE 108
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// a buffer for data received from the XBee
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char arrival_buf[XBEE_BUFFER_SIZE];
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// location of last unread byte in buffer
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volatile int buffer_last = 0;
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// first unread byte in buffer
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volatile int buffer_first = 0;
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//used to store packets as they are read
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static char xbee_buf[PACKET_BUFFER_SIZE];
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static int currentBufPos = 0;
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//XBee status
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static unsigned int xbee_panID = XBEE_PAN_DEFAULT;
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static unsigned int xbee_pending_panID = XBEE_PAN_DEFAULT;
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static int xbee_channel = XBEE_CHANNEL_DEFAULT;
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static int xbee_pending_channel = XBEE_CHANNEL_DEFAULT;
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static volatile unsigned int xbee_address = 0;
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/*Function Implementations*/
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#ifdef ROBOT
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/**
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* Interrupt for the robot. Adds bytes received from the xbee
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* to the buffer.
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**/
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#ifndef FIREFLY
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ISR(USART1_RX_vect)
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{
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char c = UDR1;
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arrival_buf[buffer_last] = c;
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int t = buffer_last + 1;
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if (t == XBEE_BUFFER_SIZE)
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t = 0;
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if (t == buffer_first)
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{
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WL_DEBUG_PRINT("\nOut of space in buffer.\n");
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}
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buffer_last = t;
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}
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#else
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SIGNAL(SIG_USART0_RECV)
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{
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char c = UDR0;
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arrival_buf[buffer_last] = c;
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int t = buffer_last + 1;
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if (t == XBEE_BUFFER_SIZE)
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t = 0;
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if (t == buffer_first)
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{
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WL_DEBUG_PRINT("Out of space in buffer.\n");
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}
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buffer_last = t;
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}
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#endif
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#else
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// Computer code
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/**
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* Thread that listens to the xbee.
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**/
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static void* listen_to_xbee(void* x)
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{
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char c;
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while (1)
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{
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if (xbee_read(&c, 1) != 0) {
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WL_DEBUG_PRINT("xbee_read failed.\n");
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return NULL;
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}
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arrival_buf[buffer_last] = c;
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int t = buffer_last + 1;
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if (t == XBEE_BUFFER_SIZE)
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t = 0;
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if (t == buffer_first)
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{
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WL_DEBUG_PRINT("Out of space in buffer.\n");
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}
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buffer_last = t;
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usleep(1000);
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}
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return NULL;
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}
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#endif
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/**
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* Initializes the XBee library so that other functions may be used.
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**/
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int xbee_lib_init()
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{
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WL_DEBUG_PRINT("in xbee_init\n");
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#ifdef ROBOT
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//enable the receiving interrupt
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#ifdef FIREFLY
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UCSR0B |= _BV(RXCIE) | _BV(RXEN);
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#else
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#ifdef BAYBOARD
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UCSR1B |= _BV(RXCIE1);
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#else
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UCSR1B |= _BV(RXCIE);
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#endif
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#endif
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sei();
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#else
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xbee_stream = open(xbee_com_port, O_RDWR);
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if (xbee_stream == -1/* || lockf(xbee_stream, F_TEST, 0) != 0*/)
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{
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WL_DEBUG_PRINT("Failed to open connection to XBee on port ");
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WL_DEBUG_PRINT_INT(xbee_com_port);
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WL_DEBUG_PRINT(".\n");
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return -1;
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} else {
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WL_DEBUG_PRINT("Successfully opened connection to XBee on port ");
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WL_DEBUG_PRINT_INT(xbee_com_port);
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WL_DEBUG_PRINT(".\n");
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}
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// set baud rate, etc. correctly
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struct termios options;
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tcgetattr(xbee_stream, &options);
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cfsetispeed(&options, B9600);
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cfsetospeed(&options, B9600);
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options.c_iflag &= ~ICRNL;
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options.c_oflag &= ~OCRNL;
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options.c_cflag |= (CLOCAL | CREAD);
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options.c_cflag &= ~PARENB;
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options.c_cflag &= ~CSTOPB;
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options.c_cflag &= ~CSIZE;
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options.c_cflag |= CS8;
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options.c_lflag &= ~ICANON;
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options.c_cc[VMIN] = 1;
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options.c_cc[VTIME] = 50;
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if (tcsetattr(xbee_stream, TCSANOW, &options))
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{
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WL_DEBUG_PRINT("Error setting attributes.\n");
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return -1;
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}
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xbee_listen_thread = (pthread_t*)malloc(sizeof(pthread_t));
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if (xbee_listen_thread == NULL)
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{
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WL_DEBUG_PRINT("Malloc failed.\n");
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return -1;
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}
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int ret = pthread_create(xbee_listen_thread, NULL, listen_to_xbee, NULL);
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if (ret)
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{
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WL_DEBUG_PRINT("Failed to create listener thread.\n");
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return -1;
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}
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#endif
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WL_DEBUG_PRINT("Entering command mode.\n");
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if (xbee_enter_command_mode() != 0) {
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return -1;
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}
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WL_DEBUG_PRINT("Entered command mode.\n");
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if (xbee_enter_api_mode() != 0) {
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return -1;
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}
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WL_DEBUG_PRINT("Entered api mode.\n");
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if (xbee_exit_command_mode() != 0) {
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return -1;
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}
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WL_DEBUG_PRINT("Left command mode.\n");
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if (xbee_send_read_at_command("MY")) {
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return -1;
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}
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WL_DEBUG_PRINT("Getting ATMY address.\n");
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#ifndef ROBOT
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int i;
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for (i = 0; xbee_address == 0 && i < XBEE_GET_PACKET_TIMEOUT; i++) {
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ret = xbee_get_packet(NULL);
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usleep(1000);
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/* if (ret == -1) { */
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/* WL_DEBUG_PRINT("xbee_get_packet(NULL) failed.\n"); */
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/* return -1; */
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/* } */
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}
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#else
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//wait to return until the address is set
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//TODO: this shouldn't wait indefinitely. There should be some sort of reasonable timeout
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// so if the address is never set right, an error can be returned instead of having the
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// robot hang forever
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while (xbee_address == 0) {
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xbee_get_packet(NULL);
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}
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#endif
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WL_DEBUG_PRINT("Got ATMY address.\n");
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#ifndef ROBOT
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if (i == XBEE_GET_PACKET_TIMEOUT) { // We timed-out.
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WL_DEBUG_PRINT("xbee_get_packet timed out.\n");
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return -1;
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} else {
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return 0;
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}
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#else
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return 0;
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#endif
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}
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/**
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* Call when finished using the XBee library. This releases
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* all sued resources.
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**/
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void xbee_terminate()
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{
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#ifndef ROBOT
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pthread_cancel(*xbee_listen_thread);
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pthread_join(*xbee_listen_thread, NULL);
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free(xbee_listen_thread);
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lockf(xbee_stream, F_ULOCK, 0);
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close(xbee_stream);
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#endif
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}
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/**
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* Send a buffer buf of size bytes to the XBee.
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*
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* @param buf the buffer of data to send
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* @param size the number of bytes to send
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**/
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static int xbee_send(char* buf, int size)
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{
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#ifdef ROBOT
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int i;
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for (i = 0; i < size; i++) {
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xbee_putc(buf[i]);
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}
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return 0;
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#else
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int ret = write(xbee_stream, buf, size);
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//success
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if (ret == size)
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return 0;
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if (ret == -1)
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{
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//interrupted by system signal, probably timer interrupt.
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//just try again
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if (errno == 4)
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{
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return xbee_send(buf, size);
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}
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WL_DEBUG_PRINT("Failed to write to xbee\r\n");
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return -1;
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387 |
}
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388 |
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//write was interrupted after writing ret bytes
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return xbee_send(buf + ret, size - ret);
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#endif
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392 |
}
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393 |
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394 |
/**
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395 |
* Sends a string to the XBee.
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*
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397 |
* @param c the string to send to the XBEE
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398 |
**/
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399 |
static int xbee_send_string(char* c)
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{
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return xbee_send(c, strlen(c));
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}
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403 |
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#ifndef ROBOT
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static int xbee_read(char* buf, int size)
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{
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if (read(xbee_stream, buf, size) == -1) {
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WL_DEBUG_PRINT("Failed to read from xbee.\r\n");
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return -1;
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410 |
}
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411 |
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412 |
return 0;
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413 |
}
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|
414 |
#endif
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415 |
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416 |
/**
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417 |
* Enter into command mode.
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418 |
**/
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419 |
static int xbee_enter_command_mode()
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420 |
{
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421 |
if (xbee_send_string("+++") != 0) {
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422 |
return -1;
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423 |
}
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424 |
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425 |
if (xbee_wait_for_ok() != 0) {
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426 |
return -1;
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|
427 |
}
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|
428 |
return 0;
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|
429 |
}
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|
430 |
|
|
431 |
/**
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|
432 |
* Exit from command mode.
|
|
433 |
**/
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|
434 |
static int xbee_exit_command_mode()
|
|
435 |
{
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|
436 |
if (xbee_send_string("ATCN\r") != 0) {
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437 |
return -1;
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|
438 |
}
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|
439 |
|
|
440 |
xbee_wait_for_ok();
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|
441 |
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|
442 |
return 0;
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|
443 |
}
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|
444 |
|
|
445 |
/**
|
|
446 |
* Enter API mode.
|
|
447 |
**/
|
|
448 |
static int xbee_enter_api_mode()
|
|
449 |
{
|
|
450 |
if (xbee_send_string("ATAP 1\r") != 0) {
|
|
451 |
return -1;
|
|
452 |
}
|
|
453 |
xbee_wait_for_ok();
|
|
454 |
|
|
455 |
return 0;
|
|
456 |
}
|
|
457 |
|
|
458 |
/**
|
|
459 |
* Wait until the string "OK\r" is received from the XBee.
|
|
460 |
**/
|
|
461 |
static int xbee_wait_for_ok()
|
|
462 |
{
|
|
463 |
return xbee_wait_for_string("OK\r", 3);
|
|
464 |
}
|
|
465 |
|
|
466 |
/**
|
|
467 |
* Delay until the specified string is received from
|
|
468 |
* the XBee. Discards all other XBee data.
|
|
469 |
*
|
|
470 |
* ********* Robot often hangs here ****************
|
|
471 |
*
|
|
472 |
* @param s the string to receive
|
|
473 |
* @param len the length of the string
|
|
474 |
**/
|
|
475 |
static int xbee_wait_for_string(char* s, int len)
|
|
476 |
{
|
|
477 |
char* curr = s;
|
|
478 |
while (curr - s < len) {
|
|
479 |
WL_DEBUG_PRINT("waiting for string\r\n");
|
|
480 |
// check if buffer is empty
|
|
481 |
if (buffer_last != buffer_first) {
|
|
482 |
char c = arrival_buf[buffer_first++];
|
|
483 |
if (buffer_first == XBEE_BUFFER_SIZE) {
|
|
484 |
buffer_first = 0;
|
|
485 |
}
|
|
486 |
|
|
487 |
if (c == *curr) {
|
|
488 |
curr++;
|
|
489 |
} else {
|
|
490 |
#ifndef ROBOT
|
|
491 |
//return -1; // Computer is less forgiving.
|
|
492 |
curr = s;
|
|
493 |
#else
|
|
494 |
curr = s;
|
|
495 |
#endif
|
|
496 |
}
|
|
497 |
} // else buffer is empty.
|
|
498 |
|
|
499 |
#ifndef ROBOT
|
|
500 |
usleep(100);
|
|
501 |
#endif
|
|
502 |
}
|
|
503 |
|
|
504 |
return 0;
|
|
505 |
}
|
|
506 |
|
|
507 |
/**
|
|
508 |
* Verifies that the packets checksum is correct.
|
|
509 |
* (If the checksum is correct, the sum of the bytes
|
|
510 |
* is 0xFF.)
|
|
511 |
*
|
|
512 |
* @param packet the packet received. This includes the first
|
|
513 |
* three bytes, which are header information from the XBee.
|
|
514 |
*
|
|
515 |
* @param len The length of the packet received from the XBee
|
|
516 |
*
|
|
517 |
* @return 0 if the checksum is incorrect, nonzero
|
|
518 |
* otherwise
|
|
519 |
**/
|
|
520 |
int xbee_verify_checksum(char* packet, int len)
|
|
521 |
{
|
|
522 |
unsigned char sum = 0;
|
|
523 |
int i;
|
|
524 |
for (i = 3; i < len; i++)
|
|
525 |
sum += (unsigned char)packet[i];
|
|
526 |
return sum == 0xFF;
|
|
527 |
}
|
|
528 |
|
|
529 |
/**
|
|
530 |
* Returns the checksum of the given packet.
|
|
531 |
*
|
|
532 |
* @param buf the data for the packet to send
|
|
533 |
* @param len the length of the packet in bytes
|
|
534 |
*
|
|
535 |
* @return the checksum of the packet, which will
|
|
536 |
* become the last byte sent in the packet
|
|
537 |
**/
|
|
538 |
char xbee_compute_checksum(char* buf, int len)
|
|
539 |
{
|
|
540 |
int i;
|
|
541 |
unsigned char sum = 0;
|
|
542 |
for (i = 0; i < len; i++)
|
|
543 |
sum += (unsigned char)buf[i];
|
|
544 |
return 0xFF - sum;
|
|
545 |
}
|
|
546 |
|
|
547 |
/**
|
|
548 |
* Adds header information and checksum to the given
|
|
549 |
* packet and sends it. Header information includes
|
|
550 |
* XBEE_FRAME_START and the packet length, as two bytes.
|
|
551 |
*
|
|
552 |
* @param buf the packet data
|
|
553 |
* @param len the size in bytes of the packet data
|
|
554 |
*
|
|
555 |
**/
|
|
556 |
static int xbee_send_frame(char* buf, int len)
|
|
557 |
{
|
|
558 |
char prefix[3];
|
|
559 |
prefix[0] = XBEE_FRAME_START;
|
|
560 |
prefix[1] = (len & 0xFF00) >> 8;
|
|
561 |
prefix[2] = len & 0xFF;
|
|
562 |
char checksum = xbee_compute_checksum(buf, len);
|
|
563 |
|
|
564 |
if (xbee_send(prefix, 3) != 0) {
|
|
565 |
return -1;
|
|
566 |
}
|
|
567 |
|
|
568 |
if (xbee_send(buf, len) != 0) {
|
|
569 |
return -1;
|
|
570 |
}
|
|
571 |
|
|
572 |
if (xbee_send(&checksum, 1) != 0) {
|
|
573 |
return -1;
|
|
574 |
}
|
|
575 |
|
|
576 |
return 0;
|
|
577 |
}
|
|
578 |
|
|
579 |
/**
|
|
580 |
* Sends an AT command to read a parameter.
|
|
581 |
*
|
|
582 |
* @param command the AT command to send. For exmaple,
|
|
583 |
* use ID to read the PAN ID and MY to return the XBee ID.
|
|
584 |
* See the XBee reference guide for a complete listing.
|
|
585 |
**/
|
|
586 |
int xbee_send_read_at_command(char* command)
|
|
587 |
{
|
|
588 |
return xbee_send_modify_at_command(command, NULL);
|
|
589 |
}
|
|
590 |
|
|
591 |
/**
|
|
592 |
* Sends the given AT command.
|
|
593 |
*
|
|
594 |
* @param command the AT command to send (e.g., MY, ID)
|
|
595 |
* @param value the value to pass as a parameter
|
|
596 |
* (or NULL if there is no parameter)
|
|
597 |
**/
|
|
598 |
static int xbee_send_modify_at_command(char* command, char* value)
|
|
599 |
{
|
|
600 |
char buf[16];
|
|
601 |
int i;
|
|
602 |
|
|
603 |
buf[0] = XBEE_FRAME_AT_COMMAND;
|
|
604 |
buf[1] = 1;
|
|
605 |
buf[2] = command[0];
|
|
606 |
buf[3] = command[1];
|
|
607 |
int valueLen = 0;
|
|
608 |
if (value != NULL)
|
|
609 |
{
|
|
610 |
valueLen = strlen(value);
|
|
611 |
if (valueLen > 8)
|
|
612 |
{
|
|
613 |
WL_DEBUG_PRINT("AT Command too large.\r\n");
|
|
614 |
return -1;
|
|
615 |
}
|
|
616 |
|
|
617 |
for (i = 0; i < valueLen; i++) {
|
|
618 |
buf[4 + i] = value[i];
|
|
619 |
}
|
|
620 |
}
|
|
621 |
|
|
622 |
return xbee_send_frame(buf, 4 + valueLen);
|
|
623 |
}
|
|
624 |
|
|
625 |
/**
|
|
626 |
* Send the specified packet.
|
|
627 |
*
|
|
628 |
* @param packet the packet data to send
|
|
629 |
* @param len the number of bytes in the packet
|
|
630 |
*
|
|
631 |
* @param dest the ID of the XBee to send the packet to,
|
|
632 |
* or XBEE_BROADCAST to send the message to all robots
|
|
633 |
* in the PAN.
|
|
634 |
*
|
|
635 |
* @param options a combination of the flags
|
|
636 |
* XBEE_OPTIONS_NONE, XBEE_OPTIONS_DISABLE_RESPONSE and
|
|
637 |
* XBEE_OPTIONS_BROADCAST_ALL_PANS
|
|
638 |
*
|
|
639 |
* @param frame the frame number to associate this packet
|
|
640 |
* with. This will be used to identify the response when
|
|
641 |
* the XBee alerts us as to whether or not our message
|
|
642 |
* was received.
|
|
643 |
**/
|
|
644 |
int xbee_send_packet(char* packet, int len, int dest, char options, char frame)
|
|
645 |
{
|
|
646 |
char buf[5];
|
|
647 |
char prefix[3];
|
|
648 |
int i;
|
|
649 |
unsigned char checksum = 0;
|
|
650 |
|
|
651 |
if (len > 100)
|
|
652 |
{
|
|
653 |
WL_DEBUG_PRINT("Packet is too large.\r\n");
|
|
654 |
return -1;
|
|
655 |
}
|
|
656 |
|
|
657 |
//data for sending request
|
|
658 |
buf[0] = XBEE_FRAME_TX_REQUEST_16;
|
|
659 |
buf[1] = frame;
|
|
660 |
buf[2] = (dest >> 8) & 0xFF;
|
|
661 |
buf[3] = dest & 0xFF;
|
|
662 |
buf[4] = options;
|
|
663 |
|
|
664 |
//packet prefix, do this here so we don't need an extra buffer
|
|
665 |
prefix[0] = XBEE_FRAME_START;
|
|
666 |
prefix[1] = ((5 + len) & 0xFF00) >> 8;
|
|
667 |
prefix[2] = (5 + len) & 0xFF;
|
|
668 |
|
|
669 |
for (i = 0; i < 5; i++)
|
|
670 |
checksum += (unsigned char)buf[i];
|
|
671 |
for (i = 0; i < len; i++)
|
|
672 |
checksum += (unsigned char)packet[i];
|
|
673 |
checksum = 0xFF - checksum;
|
|
674 |
|
|
675 |
if (xbee_send(prefix, 3) != 0) {
|
|
676 |
return -1;
|
|
677 |
}
|
|
678 |
|
|
679 |
if (xbee_send(buf, 5) != 0) {
|
|
680 |
return -1;
|
|
681 |
}
|
|
682 |
|
|
683 |
if (xbee_send(packet, len) != 0) {
|
|
684 |
return -1;
|
|
685 |
}
|
|
686 |
|
|
687 |
if (xbee_send((char*)&checksum, 1) != 0) {
|
|
688 |
return -1;
|
|
689 |
}
|
|
690 |
|
|
691 |
return 0;
|
|
692 |
}
|
|
693 |
|
|
694 |
/**
|
|
695 |
* Reads a packet received from the XBee. This function
|
|
696 |
* is non-blocking. The resulting packet is stored in dest.
|
|
697 |
* Only returns transmission response packets and
|
|
698 |
* received packets. The returned packet does not include
|
|
699 |
* header information or the checksum. This method also
|
|
700 |
* handles special packets dealt with by the XBee library,
|
|
701 |
* and so should be called frequently while the XBee is in
|
|
702 |
* use.<br><br>
|
|
703 |
*
|
|
704 |
* The first byte of the packet will be either
|
|
705 |
* XBEE_TX_STATUS or XBEE_RX to indicated
|
|
706 |
* a response to a sent message or a received message,
|
|
707 |
* respectively.<br><br>
|
|
708 |
*
|
|
709 |
* For a status response packet:<br>
|
|
710 |
* The first byte will be XBEE_TX_STATUS.<br>
|
|
711 |
* The second byte will be the frame number.<br>
|
|
712 |
* The third byte will be the result. 0 indicates success,
|
|
713 |
* and nonzero indicates that an error ocurred in
|
|
714 |
* transmitting the packet.<br><br>
|
|
715 |
*
|
|
716 |
* For a received packet:<br>
|
|
717 |
* The first byte will be XBEE_RX.<br>
|
|
718 |
* The second and third bytes will be the 16-bit
|
|
719 |
* address of the packet's sender.<br>
|
|
720 |
* The fourth byte is the signal strength.<br>
|
|
721 |
* The fifth byte is 1 if the packet were sent to
|
|
722 |
* a specific address, and 2 if it is a broadcast packet.<br><br>
|
|
723 |
*
|
|
724 |
* @param dest set to the packet data
|
|
725 |
* @return the length of the packet, or -1 if no packet
|
|
726 |
* is available
|
|
727 |
**/
|
|
728 |
int xbee_get_packet(unsigned char* dest)
|
|
729 |
{
|
|
730 |
int ret;
|
|
731 |
//start reading a packet with XBEE_FRAME_START
|
|
732 |
if (currentBufPos == 0)
|
|
733 |
{
|
|
734 |
do
|
|
735 |
{
|
|
736 |
if (buffer_first == XBEE_BUFFER_SIZE)
|
|
737 |
buffer_first = 0;
|
|
738 |
// check if buffer is empty
|
|
739 |
if (buffer_first == buffer_last) {
|
|
740 |
return -1;
|
|
741 |
}
|
|
742 |
} while (arrival_buf[buffer_first++] != XBEE_FRAME_START);
|
|
743 |
|
|
744 |
if (buffer_first == XBEE_BUFFER_SIZE) {
|
|
745 |
buffer_first = 0;
|
|
746 |
}
|
|
747 |
xbee_buf[0] = XBEE_FRAME_START;
|
|
748 |
currentBufPos++;
|
|
749 |
}
|
|
750 |
|
|
751 |
int len = -1;
|
|
752 |
if (currentBufPos >= 3) {
|
|
753 |
len = (int)xbee_buf[2] + ((int)xbee_buf[1] << 8);
|
|
754 |
}
|
|
755 |
|
|
756 |
while (len == -1 //packet length has not been read yet
|
|
757 |
|| currentBufPos < len + 4)
|
|
758 |
{
|
|
759 |
if (currentBufPos == 3)
|
|
760 |
{
|
|
761 |
len = (int)xbee_buf[2] + ((int)xbee_buf[1] << 8);
|
|
762 |
if (len > 120)
|
|
763 |
{
|
|
764 |
WL_DEBUG_PRINT("Packet too large. Probably error in XBee transmission.\n");
|
|
765 |
currentBufPos = 0;
|
|
766 |
return -1;
|
|
767 |
}
|
|
768 |
}
|
|
769 |
|
|
770 |
// check if buffer is empty
|
|
771 |
if (buffer_first == buffer_last) {
|
|
772 |
return -1;
|
|
773 |
}
|
|
774 |
xbee_buf[currentBufPos++] = arrival_buf[buffer_first++];
|
|
775 |
if (buffer_first == XBEE_BUFFER_SIZE) {
|
|
776 |
buffer_first = 0;
|
|
777 |
}
|
|
778 |
}
|
|
779 |
|
|
780 |
currentBufPos = 0;
|
|
781 |
|
|
782 |
if (!xbee_verify_checksum(xbee_buf, len + 4))
|
|
783 |
{
|
|
784 |
WL_DEBUG_PRINT("XBee checksum failed.\r\n");
|
|
785 |
return -1;
|
|
786 |
}
|
|
787 |
|
|
788 |
//we will take care of the packet
|
|
789 |
|
|
790 |
ret = xbee_handle_packet(xbee_buf+3, len);
|
|
791 |
if (ret == 1) {
|
|
792 |
return 3;
|
|
793 |
}
|
|
794 |
|
|
795 |
if (dest == NULL) {
|
|
796 |
return -1;
|
|
797 |
}
|
|
798 |
|
|
799 |
int i;
|
|
800 |
for (i = 3; i < len + 3; i++) {
|
|
801 |
dest[i - 3] = xbee_buf[i];
|
|
802 |
}
|
|
803 |
return len;
|
|
804 |
}
|
|
805 |
|
|
806 |
/**
|
|
807 |
* Handles modem status packets.
|
|
808 |
*
|
|
809 |
* @param status the type of status packet received.
|
|
810 |
**/
|
|
811 |
void xbee_handle_status(char status)
|
|
812 |
{
|
|
813 |
switch (status)
|
|
814 |
{
|
|
815 |
case 0:
|
|
816 |
WL_DEBUG_PRINT("XBee hardware reset.\r\n");
|
|
817 |
break;
|
|
818 |
case 1:
|
|
819 |
WL_DEBUG_PRINT("Watchdog timer reset.\r\n");
|
|
820 |
break;
|
|
821 |
case 2:
|
|
822 |
WL_DEBUG_PRINT("Associated.\r\n");
|
|
823 |
break;
|
|
824 |
case 3:
|
|
825 |
WL_DEBUG_PRINT("Disassociated.\r\n");
|
|
826 |
break;
|
|
827 |
case 4:
|
|
828 |
WL_DEBUG_PRINT("Synchronization lost.\r\n");
|
|
829 |
break;
|
|
830 |
case 5:
|
|
831 |
WL_DEBUG_PRINT("Coordinator realignment.\r\n");
|
|
832 |
break;
|
|
833 |
case 6:
|
|
834 |
WL_DEBUG_PRINT("Coordinator started.\r\n");
|
|
835 |
break;
|
|
836 |
}
|
|
837 |
}
|
|
838 |
|
|
839 |
/**
|
|
840 |
* Handles AT command response packets.
|
|
841 |
* @param command the two character AT command, e.g. MY or ID
|
|
842 |
* @param result 0 for success, 1 for an error
|
|
843 |
* @param extra the hex value of the requested register
|
|
844 |
* @param extraLen the length in bytes of extra
|
|
845 |
**/
|
|
846 |
static void xbee_handle_at_command_response(char* command, char result, char* extra, int extraLen)
|
|
847 |
{
|
|
848 |
if (result == 1)
|
|
849 |
{
|
|
850 |
WL_DEBUG_PRINT("Error with AT");
|
|
851 |
WL_DEBUG_PRINT(command);
|
|
852 |
WL_DEBUG_PRINT(" packet.\r\n");
|
|
853 |
}
|
|
854 |
WL_DEBUG_PRINT("AT");
|
|
855 |
WL_DEBUG_PRINT(command);
|
|
856 |
WL_DEBUG_PRINT(" command was successful.\r\n");
|
|
857 |
|
|
858 |
if (command[0] == 'I' && command[1] == 'D')
|
|
859 |
{
|
|
860 |
xbee_panID = xbee_pending_panID;
|
|
861 |
WL_DEBUG_PRINT("PAN ID set to ");
|
|
862 |
WL_DEBUG_PRINT_INT(xbee_panID);
|
|
863 |
WL_DEBUG_PRINT(".\r\n");
|
|
864 |
return;
|
|
865 |
}
|
|
866 |
|
|
867 |
if (command[0] == 'C' && command[1] == 'H')
|
|
868 |
{
|
|
869 |
xbee_channel = xbee_pending_channel;
|
|
870 |
WL_DEBUG_PRINT("Channel set to ");
|
|
871 |
WL_DEBUG_PRINT_INT(xbee_channel);
|
|
872 |
WL_DEBUG_PRINT(".\r\n");
|
|
873 |
return;
|
|
874 |
}
|
|
875 |
|
|
876 |
if (command[0] == 'M' && command[1] == 'Y' && extraLen != 0)
|
|
877 |
{
|
|
878 |
xbee_address = 0;
|
|
879 |
int i;
|
|
880 |
for (i = 0; i < extraLen; i++) {
|
|
881 |
xbee_address = (xbee_address << 8) + extra[i];
|
|
882 |
}
|
|
883 |
|
|
884 |
WL_DEBUG_PRINT("XBee address is ");
|
|
885 |
WL_DEBUG_PRINT_INT(xbee_address);
|
|
886 |
WL_DEBUG_PRINT(".\r\n");
|
|
887 |
|
|
888 |
if (xbee_address == 0)
|
|
889 |
{
|
|
890 |
WL_DEBUG_PRINT("XBee 16-bit address must be set using ATMY.\r\n");
|
|
891 |
#ifndef ROBOT
|
|
892 |
exit(0);
|
|
893 |
#endif
|
|
894 |
}
|
|
895 |
}
|
|
896 |
}
|
|
897 |
|
|
898 |
/**
|
|
899 |
* Attempts to handle the packet if it is dealt with
|
|
900 |
* by the library.
|
|
901 |
* We will handle the following packet types:
|
|
902 |
* Modem Status
|
|
903 |
* AT Command Response
|
|
904 |
*
|
|
905 |
* @param packet the packet to handle
|
|
906 |
* @param len the length of the packet
|
|
907 |
*
|
|
908 |
* @return 1 if we have handled the packet, 0 otherwise
|
|
909 |
*/
|
|
910 |
static int xbee_handle_packet(char* packet, int len)
|
|
911 |
{
|
|
912 |
|
|
913 |
char command[3] = {1, 2, 3};
|
|
914 |
if (len <= 0) //this should not happend
|
|
915 |
{
|
|
916 |
WL_DEBUG_PRINT("Non-positive packet length.\r\n");
|
|
917 |
return 0;
|
|
918 |
}
|
|
919 |
|
|
920 |
switch ((unsigned char)packet[0]) //packet type
|
|
921 |
{
|
|
922 |
case XBEE_FRAME_STATUS:
|
|
923 |
xbee_handle_status(packet[1]);
|
|
924 |
return 1;
|
|
925 |
case XBEE_FRAME_AT_COMMAND_RESPONSE:
|
|
926 |
command[0] = packet[2];
|
|
927 |
command[1] = packet[3];
|
|
928 |
command[2] = 0;
|
|
929 |
xbee_handle_at_command_response(command, packet[4], packet + 5, len - 5);
|
|
930 |
return 1;
|
|
931 |
}
|
|
932 |
return 0;
|
|
933 |
}
|
|
934 |
|
|
935 |
/**
|
|
936 |
* Sets the personal area network id.
|
|
937 |
*
|
|
938 |
* @param id the new personal area network (PAN) id
|
|
939 |
**/
|
|
940 |
int xbee_set_pan_id(int id)
|
|
941 |
{
|
|
942 |
char s[3];
|
|
943 |
s[0] = (id >> 8) & 0xFF;
|
|
944 |
s[1] = id & 0xFF;
|
|
945 |
s[2] = 0;
|
|
946 |
xbee_pending_panID = id;
|
|
947 |
return xbee_send_modify_at_command("ID", s);
|
|
948 |
}
|
|
949 |
|
|
950 |
/**
|
|
951 |
* Get the PAN ID for the XBee.
|
|
952 |
*
|
|
953 |
* @return the personal area network id, or
|
|
954 |
* XBEE_PAN_DEFAULT if it has not yet been set.
|
|
955 |
**/
|
|
956 |
unsigned int xbee_get_pan_id()
|
|
957 |
{
|
|
958 |
return xbee_panID;
|
|
959 |
}
|
|
960 |
|
|
961 |
/**
|
|
962 |
* Set the channel the XBee is using.
|
|
963 |
*
|
|
964 |
* @param channel the channel the XBee will not use,
|
|
965 |
* between 0x0B and 0x1A
|
|
966 |
*
|
|
967 |
* @see xbee_get_channel
|
|
968 |
**/
|
|
969 |
int xbee_set_channel(int channel)
|
|
970 |
{
|
|
971 |
if (channel < 0x0B || channel > 0x1A)
|
|
972 |
{
|
|
973 |
WL_DEBUG_PRINT("Channel out of range.\r\n");
|
|
974 |
return -1;
|
|
975 |
}
|
|
976 |
|
|
977 |
char s[3];
|
|
978 |
s[0] = channel & 0xFF;
|
|
979 |
s[1] = 0;
|
|
980 |
xbee_pending_channel = channel;
|
|
981 |
|
|
982 |
return xbee_send_modify_at_command("CH", s);
|
|
983 |
}
|
|
984 |
|
|
985 |
/**
|
|
986 |
* Returns the channel which the XBee is currently using.
|
|
987 |
*
|
|
988 |
* @return the channel the XBee is using
|
|
989 |
*
|
|
990 |
* @see xbee_set_channel
|
|
991 |
**/
|
|
992 |
int xbee_get_channel(void)
|
|
993 |
{
|
|
994 |
return xbee_channel;
|
|
995 |
}
|
|
996 |
|
|
997 |
/**
|
|
998 |
* Get the 16-bit address of the XBee.
|
|
999 |
* This is used to specify who to send messages to
|
|
1000 |
* and who messages are from.
|
|
1001 |
*
|
|
1002 |
* @return the 16-bit address of the XBee.
|
|
1003 |
**/
|
|
1004 |
unsigned int xbee_get_address()
|
|
1005 |
{
|
|
1006 |
return xbee_address;
|
|
1007 |
}
|
|
1008 |
|
|
1009 |
#ifndef ROBOT
|
|
1010 |
void xbee_set_com_port(char* port)
|
|
1011 |
{
|
|
1012 |
xbee_com_port = port;
|
|
1013 |
}
|
|
1014 |
#endif
|