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1 | 242 | bcoltin | /**
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2 | * Copyright (c) 2007 Colony Project
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3 | 409 | emarinel | *
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4 | 242 | bcoltin | * Permission is hereby granted, free of charge, to any person
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5 | * obtaining a copy of this software and associated documentation
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6 | * files (the "Software"), to deal in the Software without
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7 | * restriction, including without limitation the rights to use,
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8 | * copy, modify, merge, publish, distribute, sublicense, and/or sell
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9 | * copies of the Software, and to permit persons to whom the
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10 | * Software is furnished to do so, subject to the following
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11 | * conditions:
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12 | 409 | emarinel | *
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13 | 242 | bcoltin | * The above copyright notice and this permission notice shall be
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14 | * included in all copies or substantial portions of the Software.
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15 | 409 | emarinel | *
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16 | 242 | bcoltin | * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
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17 | * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES
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18 | * OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
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19 | * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT
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20 | * HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
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21 | * WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
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22 | * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
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23 | * OTHER DEALINGS IN THE SOFTWARE.
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24 | **/
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25 | |||
26 | /**
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27 | * @file xbee.c
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28 | * @brief XBee Interface
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29 | *
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30 | * Implementation of low level communication with the XBee in API mode.
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31 | *
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32 | * @author Brian Coltin, Colony Project, CMU Robotics Club
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33 | **/
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34 | |||
35 | 17 | bcoltin | #include "xbee.h" |
36 | #include "wl_defs.h" |
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37 | |||
38 | #ifndef ROBOT
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39 | |||
40 | #include <fcntl.h> |
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41 | #include <unistd.h> |
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42 | #include <pthread.h> |
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43 | #include <errno.h> |
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44 | 309 | emarinel | #include <termios.h> |
45 | 17 | bcoltin | |
46 | #else
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47 | |||
48 | #include <serial.h> |
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49 | #include <avr/interrupt.h> |
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50 | |||
51 | #endif
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52 | |||
53 | #include <stdio.h> |
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54 | #include <stdlib.h> |
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55 | #include <string.h> |
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56 | |||
57 | #define XBEE_FRAME_START 0x7E |
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58 | |||
59 | /*Frame Types*/
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60 | #define XBEE_FRAME_STATUS 0x8A |
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61 | #define XBEE_FRAME_AT_COMMAND 0x08 |
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62 | #define XBEE_FRAME_AT_COMMAND_RESPONSE 0x88 |
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63 | #define XBEE_FRAME_TX_REQUEST_64 0x00 |
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64 | #define XBEE_FRAME_TX_REQUEST_16 0x01 |
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65 | #define XBEE_FRAME_TX_STATUS XBEE_TX_STATUS
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66 | #define XBEE_FRAME_RX_64 0x80 |
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67 | #define XBEE_FRAME_RX_16 XBEE_RX
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68 | |||
69 | /*Internal Function Prototypes*/
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70 | |||
71 | /*I/O Functions*/
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72 | 397 | emarinel | static int xbee_send(char* buf, int size); |
73 | static void xbee_send_string(char* c); |
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74 | 17 | bcoltin | |
75 | #ifndef ROBOT
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76 | void xbee_read(char* buf, int size); |
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77 | #endif
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78 | |||
79 | /*Command Mode Functions
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80 | * Called during initialization.
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81 | */
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82 | 409 | emarinel | static void xbee_enter_command_mode(void); |
83 | static void xbee_exit_command_mode(void); |
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84 | static void xbee_enter_api_mode(void); |
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85 | static void xbee_exit_api_mode(void); |
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86 | static void xbee_wait_for_string(char* s, int len); |
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87 | static void xbee_wait_for_ok(void); |
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88 | 17 | bcoltin | |
89 | /*API Mode Functions*/
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90 | |||
91 | int xbee_handle_packet(char* packet, int len); |
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92 | 397 | emarinel | void xbee_handle_at_command_response(char* command, char result, char* extra, int extraLen); |
93 | 17 | bcoltin | void xbee_handle_status(char status); |
94 | int xbee_verify_checksum(char* packet, int len); |
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95 | char xbee_compute_checksum(char* packet, int len); |
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96 | void xbee_send_frame(char* buf, int len); |
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97 | void xbee_send_read_at_command(char* command); |
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98 | void xbee_send_modify_at_command(char* command, char* value); |
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99 | |||
100 | /*Global Variables*/
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101 | |||
102 | #ifndef ROBOT
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103 | 399 | emarinel | static char* xbee_com_port = XBEE_PORT_DEFAULT; |
104 | static int xbee_stream; |
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105 | static pthread_t* xbee_listen_thread;
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106 | 17 | bcoltin | #endif
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107 | |||
108 | 336 | bcoltin | // TODO: is this a good size?
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109 | #define XBEE_BUFFER_SIZE 256 |
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110 | // a buffer for data received from the XBee
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111 | char arrival_buf[XBEE_BUFFER_SIZE];
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112 | // location of last unread byte in buffer
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113 | volatile int buffer_last = 0; |
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114 | // first unread byte in buffer
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115 | volatile int buffer_first = 0; |
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116 | 17 | bcoltin | |
117 | 336 | bcoltin | |
118 | 17 | bcoltin | //used to store packets as they are read
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119 | char xbee_buf[128]; |
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120 | int currentBufPos = 0; |
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121 | |||
122 | //XBee status
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123 | unsigned int xbee_panID = XBEE_PAN_DEFAULT; |
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124 | unsigned int xbee_pending_panID = XBEE_PAN_DEFAULT; |
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125 | 60 | bcoltin | int xbee_channel = XBEE_CHANNEL_DEFAULT;
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126 | int xbee_pending_channel = XBEE_CHANNEL_DEFAULT;
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127 | 17 | bcoltin | unsigned int xbee_address = 0; |
128 | |||
129 | /*Function Implementations*/
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130 | |||
131 | #ifdef ROBOT
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132 | |||
133 | /**
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134 | * Interrupt for the robot. Adds bytes received from the xbee
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135 | 336 | bcoltin | * to the buffer.
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136 | 17 | bcoltin | **/
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137 | 86 | bcoltin | #ifndef FIREFLY
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138 | 346 | bcoltin | ISR(USART1_RX_vect) |
139 | { |
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140 | char c = UDR1;
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141 | arrival_buf[buffer_last] = c; |
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142 | int t = buffer_last + 1; |
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143 | if (t == XBEE_BUFFER_SIZE)
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144 | t = 0;
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145 | if (t == buffer_first)
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146 | { |
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147 | WL_DEBUG_PRINT("Out of space in buffer.\n");
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148 | } |
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149 | buffer_last = t; |
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150 | 17 | bcoltin | } |
151 | 86 | bcoltin | #else
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152 | 346 | bcoltin | SIGNAL(SIG_USART0_RECV) |
153 | { |
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154 | char c = UDR0;
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155 | arrival_buf[buffer_last] = c; |
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156 | int t = buffer_last + 1; |
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157 | if (t == XBEE_BUFFER_SIZE)
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158 | t = 0;
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159 | if (t == buffer_first)
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160 | { |
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161 | WL_DEBUG_PRINT("Out of space in buffer.\n");
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162 | } |
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163 | buffer_last = t; |
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164 | 86 | bcoltin | } |
165 | #endif
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166 | 17 | bcoltin | |
167 | #else
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168 | |||
169 | /**
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170 | * Thread that listens to the xbee.
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171 | **/
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172 | 346 | bcoltin | void* listen_to_xbee(void* x) |
173 | { |
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174 | char c;
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175 | while (1) |
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176 | { |
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177 | xbee_read(&c, 1);
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178 | arrival_buf[buffer_last] = c; |
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179 | int t = buffer_last + 1; |
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180 | if (t == XBEE_BUFFER_SIZE)
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181 | t = 0;
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182 | if (t == buffer_first)
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183 | { |
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184 | WL_DEBUG_PRINT("Out of space in buffer.\n");
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185 | } |
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186 | buffer_last = t; |
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187 | 409 | emarinel | |
188 | usleep(1000);
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189 | 346 | bcoltin | } |
190 | return 0; |
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191 | 17 | bcoltin | } |
192 | |||
193 | #endif
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194 | |||
195 | /**
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196 | * Initializes the XBee library so that other functions may be used.
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197 | **/
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198 | 399 | emarinel | int xbee_lib_init()
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199 | 346 | bcoltin | { |
200 | arrival_buf[0] = 'A'; |
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201 | arrival_buf[1] = 'A'; |
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202 | arrival_buf[2] = 'A'; |
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203 | #ifdef ROBOT
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204 | 17 | bcoltin | |
205 | 346 | bcoltin | //enable the receiving interrupt
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206 | #ifdef FIREFLY
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207 | UCSR0B |= _BV(RXCIE) | _BV(RXEN); |
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208 | #else
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209 | UCSR1B |= _BV(RXCIE); |
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210 | #endif
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211 | sei(); |
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212 | #else
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213 | printf("Connecting to port %s.\n", xbee_com_port);
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214 | xbee_stream = open(xbee_com_port, O_RDWR); |
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215 | if (xbee_stream == -1/* || lockf(xbee_stream, F_TEST, 0) != 0*/) |
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216 | { |
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217 | printf("Failed to open connection to XBee on port %s\r\n", xbee_com_port);
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218 | return -1; |
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219 | } |
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220 | 409 | emarinel | |
221 | 346 | bcoltin | // set baud rate, etc. correctly
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222 | struct termios options;
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223 | 309 | emarinel | |
224 | 346 | bcoltin | tcgetattr(xbee_stream, &options); |
225 | cfsetispeed(&options, B9600); |
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226 | cfsetospeed(&options, B9600); |
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227 | options.c_iflag &= ~ICRNL; |
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228 | options.c_oflag &= ~OCRNL; |
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229 | options.c_cflag |= (CLOCAL | CREAD); |
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230 | options.c_cflag &= ~PARENB; |
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231 | options.c_cflag &= ~CSTOPB; |
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232 | options.c_cflag &= ~CSIZE; |
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233 | options.c_cflag |= CS8; |
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234 | options.c_lflag &= ~ICANON; |
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235 | options.c_cc[VMIN] = 1;
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236 | options.c_cc[VTIME] = 50;
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237 | 309 | emarinel | |
238 | 346 | bcoltin | if (tcsetattr(xbee_stream, TCSANOW, &options))
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239 | { |
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240 | fprintf(stderr, "Error setting attributes.\n");
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241 | return -1; |
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242 | } |
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243 | 309 | emarinel | |
244 | 346 | bcoltin | //lockf(xbee_stream, F_LOCK, 0);
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245 | 409 | emarinel | |
246 | xbee_listen_thread = (pthread_t*)malloc(sizeof(pthread_t));
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247 | 346 | bcoltin | if (xbee_listen_thread == NULL) |
248 | { |
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249 | fprintf(stderr, "%s: Malloc failed.\n", __FUNCTION__);
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250 | return -1; |
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251 | } |
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252 | 409 | emarinel | |
253 | int ret = pthread_create(xbee_listen_thread, NULL, listen_to_xbee, NULL); |
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254 | 346 | bcoltin | if (ret)
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255 | { |
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256 | fprintf(stderr, "Failed to create listener thread.\r\n");
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257 | return -1; |
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258 | } |
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259 | 409 | emarinel | |
260 | 346 | bcoltin | #endif
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261 | xbee_enter_command_mode(); |
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262 | xbee_enter_api_mode(); |
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263 | xbee_exit_command_mode(); |
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264 | xbee_send_read_at_command("MY");
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265 | 409 | emarinel | |
266 | 346 | bcoltin | //wait to return until the address is set
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267 | while (xbee_address == 0) xbee_get_packet(NULL); |
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268 | 309 | emarinel | |
269 | 346 | bcoltin | |
270 | return 0; |
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271 | 17 | bcoltin | } |
272 | |||
273 | /**
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274 | * Call when finished using the XBee library. This releases
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275 | * all sued resources.
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276 | **/
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277 | 346 | bcoltin | void xbee_terminate()
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278 | { |
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279 | #ifndef ROBOT
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280 | pthread_cancel(*xbee_listen_thread); |
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281 | free(xbee_listen_thread); |
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282 | lockf(xbee_stream, F_ULOCK, 0);
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283 | close(xbee_stream); |
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284 | #endif
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285 | 17 | bcoltin | } |
286 | |||
287 | /**
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288 | * Send a buffer buf of size bytes to the XBee.
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289 | 409 | emarinel | *
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290 | 17 | bcoltin | * @param buf the buffer of data to send
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291 | * @param size the number of bytes to send
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292 | **/
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293 | 397 | emarinel | int xbee_send(char* buf, int size) |
294 | 346 | bcoltin | { |
295 | #ifdef ROBOT
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296 | int i;
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297 | for (i = 0; i < size; i++) |
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298 | xbee_putc(buf[i]); |
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299 | #else
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300 | int ret = write(xbee_stream, buf, size);
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301 | //success
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302 | if (ret == size)
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303 | 397 | emarinel | return 0; |
304 | 346 | bcoltin | if (ret == -1) |
305 | { |
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306 | //interrupted by system signal, probably timer interrupt.
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307 | //just try again
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308 | if (errno == 4) |
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309 | { |
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310 | 397 | emarinel | return xbee_send(buf, size);
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311 | 346 | bcoltin | } |
312 | printf("Failed to write to xbee, error %i.\r\n", errno);
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313 | 397 | emarinel | return -1; |
314 | 346 | bcoltin | } |
315 | 17 | bcoltin | |
316 | 346 | bcoltin | //write was interrupted after writing ret bytes
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317 | xbee_send(buf + ret, size - ret); |
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318 | #endif
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319 | 397 | emarinel | |
320 | return 0; |
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321 | 17 | bcoltin | } |
322 | |||
323 | /**
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324 | * Sends a string to the XBee.
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325 | *
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326 | * @param c the string to send to the XBEE
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327 | **/
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328 | 346 | bcoltin | void xbee_send_string(char* c) |
329 | { |
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330 | xbee_send(c, strlen(c)); |
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331 | 17 | bcoltin | } |
332 | |||
333 | #ifndef ROBOT
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334 | 346 | bcoltin | void xbee_read(char* buf, int size) |
335 | { |
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336 | if (read(xbee_stream, buf, size) == -1) |
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337 | printf("Failed to read from xbee.\r\n");
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338 | 17 | bcoltin | } |
339 | #endif
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340 | |||
341 | /**
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342 | * Enter into command mode.
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343 | **/
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344 | 409 | emarinel | static void xbee_enter_command_mode() |
345 | 346 | bcoltin | { |
346 | xbee_send_string("+++");
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347 | xbee_wait_for_ok(); |
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348 | 17 | bcoltin | } |
349 | |||
350 | /**
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351 | * Exit from command mode.
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352 | **/
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353 | 409 | emarinel | static void xbee_exit_command_mode() |
354 | 346 | bcoltin | { |
355 | xbee_send_string("ATCN\r");
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356 | xbee_wait_for_ok(); |
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357 | 17 | bcoltin | } |
358 | |||
359 | /**
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360 | * Enter API mode.
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361 | **/
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362 | 409 | emarinel | static void xbee_enter_api_mode() |
363 | 346 | bcoltin | { |
364 | xbee_send_string("ATAP 1\r");
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365 | xbee_wait_for_ok(); |
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366 | 17 | bcoltin | } |
367 | |||
368 | /**
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369 | 309 | emarinel | * Exit API mode. (warning - does not check for response)
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370 | **/
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371 | 409 | emarinel | static void xbee_exit_api_mode() |
372 | 346 | bcoltin | { |
373 | xbee_send_string("ATAP 0\r");
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374 | 309 | emarinel | } |
375 | |||
376 | /**
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377 | 17 | bcoltin | * Wait until the string "OK\r" is received from the XBee.
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378 | **/
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379 | 409 | emarinel | static void xbee_wait_for_ok() |
380 | 346 | bcoltin | { |
381 | xbee_wait_for_string("OK\r", 3); |
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382 | 17 | bcoltin | } |
383 | |||
384 | /**
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385 | * Delay until the specified string is received from
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386 | * the XBee. Discards all other XBee data.
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387 | *
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388 | * @param s the string to receive
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389 | * @param len the length of the string
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390 | **/
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391 | 409 | emarinel | static void xbee_wait_for_string(char* s, int len) |
392 | 346 | bcoltin | { |
393 | 409 | emarinel | char* curr = s;
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394 | while (curr - s < len) {
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395 | // check if buffer is empty
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396 | if (buffer_last != buffer_first) {
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397 | char c = arrival_buf[buffer_first++];
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398 | if (buffer_first == XBEE_BUFFER_SIZE) {
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399 | buffer_first = 0;
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400 | } |
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401 | |||
402 | if (c == *curr) {
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403 | curr++; |
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404 | } else {
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405 | curr = s; |
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406 | } |
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407 | } |
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408 | |||
409 | usleep(1000);
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410 | } |
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411 | 17 | bcoltin | } |
412 | |||
413 | /**
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414 | * Verifies that the packets checksum is correct.
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415 | * (If the checksum is correct, the sum of the bytes
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416 | * is 0xFF.)
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417 | *
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418 | * @param packet the packet received. This includes the first
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419 | * three bytes, which are header information from the XBee.
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420 | *
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421 | * @param len The length of the packet received from the XBee
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422 | *
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423 | * @return 0 if the checksum is incorrect, nonzero
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424 | * otherwise
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425 | **/
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426 | 346 | bcoltin | int xbee_verify_checksum(char* packet, int len) |
427 | { |
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428 | unsigned char sum = 0; |
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429 | int i;
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430 | for (i = 3; i < len; i++) |
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431 | sum += (unsigned char)packet[i]; |
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432 | return sum == 0xFF; |
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433 | 17 | bcoltin | } |
434 | |||
435 | /**
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436 | * Returns the checksum of the given packet.
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437 | *
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438 | * @param buf the data for the packet to send
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439 | * @param len the length of the packet in bytes
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440 | *
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441 | * @return the checksum of the packet, which will
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442 | * become the last byte sent in the packet
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443 | **/
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444 | 346 | bcoltin | char xbee_compute_checksum(char* buf, int len) |
445 | { |
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446 | int i;
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447 | unsigned char sum = 0; |
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448 | for (i = 0; i < len; i++) |
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449 | sum += (unsigned char)buf[i]; |
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450 | return 0xFF - sum; |
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451 | 17 | bcoltin | } |
452 | |||
453 | /**
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454 | * Adds header information and checksum to the given
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455 | * packet and sends it. Header information includes
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456 | * XBEE_FRAME_START and the packet length, as two bytes.
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457 | *
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458 | * @param buf the packet data
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459 | * @param len the size in bytes of the packet data
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460 | *
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461 | **/
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462 | 346 | bcoltin | void xbee_send_frame(char* buf, int len) |
463 | { |
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464 | char prefix[3]; |
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465 | prefix[0] = XBEE_FRAME_START;
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466 | prefix[1] = (len & 0xFF00) >> 8; |
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467 | prefix[2] = len & 0xFF; |
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468 | char checksum = xbee_compute_checksum(buf, len);
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469 | xbee_send(prefix, 3);
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470 | xbee_send(buf, len); |
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471 | xbee_send(&checksum, 1);
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472 | 17 | bcoltin | } |
473 | |||
474 | /**
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475 | * Sends an AT command to read a parameter.
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476 | *
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477 | * @param command the AT command to send. For exmaple,
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478 | * use ID to read the PAN ID and MY to return the XBee ID.
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479 | * See the XBee reference guide for a complete listing.
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480 | **/
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481 | 346 | bcoltin | void xbee_send_read_at_command(char* command) |
482 | { |
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483 | xbee_send_modify_at_command(command, NULL);
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484 | 17 | bcoltin | } |
485 | |||
486 | /**
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487 | * Sends the given AT command.
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488 | *
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489 | * @param command the AT command to send (e.g., MY, ID)
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490 | * @param value the value to pass as a parameter
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491 | * (or NULL if there is no parameter)
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492 | **/
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493 | 346 | bcoltin | void xbee_send_modify_at_command(char* command, char* value) |
494 | { |
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495 | char buf[16]; |
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496 | int i;
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497 | 409 | emarinel | |
498 | 346 | bcoltin | buf[0] = XBEE_FRAME_AT_COMMAND;
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499 | buf[1] = 1; |
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500 | buf[2] = command[0]; |
||
501 | buf[3] = command[1]; |
||
502 | int valueLen = 0; |
||
503 | if (value != NULL) |
||
504 | { |
||
505 | valueLen = strlen(value); |
||
506 | if (valueLen > 8) |
||
507 | { |
||
508 | WL_DEBUG_PRINT("AT Command too large.\r\n");
|
||
509 | return;
|
||
510 | } |
||
511 | for (i = 0; i < valueLen; i++) |
||
512 | buf[4 + i] = value[i];
|
||
513 | } |
||
514 | xbee_send_frame(buf, 4 + valueLen);
|
||
515 | 17 | bcoltin | } |
516 | |||
517 | /**
|
||
518 | * Send the specified packet.
|
||
519 | 409 | emarinel | *
|
520 | 17 | bcoltin | * @param packet the packet data to send
|
521 | * @param len the number of bytes in the packet
|
||
522 | 409 | emarinel | *
|
523 | 17 | bcoltin | * @param dest the ID of the XBee to send the packet to,
|
524 | * or XBEE_BROADCAST to send the message to all robots
|
||
525 | * in the PAN.
|
||
526 | 409 | emarinel | *
|
527 | 17 | bcoltin | * @param options a combination of the flags
|
528 | 409 | emarinel | * XBEE_OPTIONS_NONE, XBEE_OPTIONS_DISABLE_RESPONSE and
|
529 | 17 | bcoltin | * XBEE_OPTIONS_BROADCAST_ALL_PANS
|
530 | *
|
||
531 | * @param frame the frame number to associate this packet
|
||
532 | * with. This will be used to identify the response when
|
||
533 | * the XBee alerts us as to whether or not our message
|
||
534 | * was received.
|
||
535 | **/
|
||
536 | 397 | emarinel | int xbee_send_packet(char* packet, int len, int dest, char options, char frame) |
537 | 346 | bcoltin | { |
538 | char buf[5]; |
||
539 | char prefix[3]; |
||
540 | int i;
|
||
541 | unsigned char checksum = 0; |
||
542 | 17 | bcoltin | |
543 | 346 | bcoltin | if (len > 100) |
544 | { |
||
545 | WL_DEBUG_PRINT("Packet is too large.\r\n");
|
||
546 | 397 | emarinel | return -1; |
547 | 346 | bcoltin | } |
548 | 17 | bcoltin | |
549 | 346 | bcoltin | //data for sending request
|
550 | buf[0] = XBEE_FRAME_TX_REQUEST_16;
|
||
551 | buf[1] = frame;
|
||
552 | buf[2] = (dest >> 8) & 0xFF; |
||
553 | buf[3] = dest & 0xFF; |
||
554 | buf[4] = options;
|
||
555 | 17 | bcoltin | |
556 | 346 | bcoltin | //packet prefix, do this here so we don't need an extra buffer
|
557 | prefix[0] = XBEE_FRAME_START;
|
||
558 | prefix[1] = ((5 + len) & 0xFF00) >> 8; |
||
559 | prefix[2] = (5 + len) & 0xFF; |
||
560 | 17 | bcoltin | |
561 | 346 | bcoltin | for (i = 0; i < 5; i++) |
562 | checksum += (unsigned char)buf[i]; |
||
563 | for (i = 0; i < len; i++) |
||
564 | checksum += (unsigned char)packet[i]; |
||
565 | checksum = 0xFF - checksum;
|
||
566 | 397 | emarinel | |
567 | if (xbee_send(prefix, 3) != 0) { |
||
568 | return -1; |
||
569 | } |
||
570 | |||
571 | if (xbee_send(buf, 5) != 0) { |
||
572 | return -1; |
||
573 | } |
||
574 | |||
575 | if (xbee_send(packet, len) != 0) { |
||
576 | return -1; |
||
577 | } |
||
578 | |||
579 | if (xbee_send((char*)&checksum, 1) != 0) { |
||
580 | return -1; |
||
581 | } |
||
582 | |||
583 | return 0; |
||
584 | 17 | bcoltin | } |
585 | |||
586 | /**
|
||
587 | * Reads a packet received from the XBee. This function
|
||
588 | * is non-blocking. The resulting packet is stored in dest.
|
||
589 | * Only returns transmission response packets and
|
||
590 | * received packets. The returned packet does not include
|
||
591 | * header information or the checksum. This method also
|
||
592 | * handles special packets dealt with by the XBee library,
|
||
593 | * and so should be called frequently while the XBee is in
|
||
594 | * use.<br><br>
|
||
595 | *
|
||
596 | * The first byte of the packet will be either
|
||
597 | * XBEE_TX_STATUS or XBEE_RX to indicated
|
||
598 | 409 | emarinel | * a response to a sent message or a received message,
|
599 | 17 | bcoltin | * respectively.<br><br>
|
600 | *
|
||
601 | * For a status response packet:<br>
|
||
602 | * The first byte will be XBEE_TX_STATUS.<br>
|
||
603 | * The second byte will be the frame number.<br>
|
||
604 | * The third byte will be the result. 0 indicates success,
|
||
605 | 409 | emarinel | * and nonzero indicates that an error ocurred in
|
606 | 17 | bcoltin | * transmitting the packet.<br><br>
|
607 | *
|
||
608 | * For a received packet:<br>
|
||
609 | * The first byte will be XBEE_RX.<br>
|
||
610 | * The second and third bytes will be the 16-bit
|
||
611 | * address of the packet's sender.<br>
|
||
612 | * The fourth byte is the signal strength.<br>
|
||
613 | * The fifth byte is 1 if the packet were sent to
|
||
614 | * a specific address, and 2 if it is a broadcast packet.<br><br>
|
||
615 | 409 | emarinel | *
|
616 | 17 | bcoltin | * @param dest set to the packet data
|
617 | * @return the length of the packet, or -1 if no packet
|
||
618 | * is available
|
||
619 | **/
|
||
620 | 346 | bcoltin | int xbee_get_packet(unsigned char* dest) |
621 | { |
||
622 | //start reading a packet with XBEE_FRAME_START
|
||
623 | if (currentBufPos == 0) |
||
624 | { |
||
625 | do
|
||
626 | { |
||
627 | if (buffer_first == XBEE_BUFFER_SIZE)
|
||
628 | buffer_first = 0;
|
||
629 | // check if buffer is empty
|
||
630 | if (buffer_first == buffer_last)
|
||
631 | return -1; |
||
632 | } |
||
633 | while (arrival_buf[buffer_first++] != XBEE_FRAME_START);
|
||
634 | if (buffer_first == XBEE_BUFFER_SIZE)
|
||
635 | buffer_first = 0;
|
||
636 | xbee_buf[0] = XBEE_FRAME_START;
|
||
637 | currentBufPos++; |
||
638 | } |
||
639 | 17 | bcoltin | |
640 | 346 | bcoltin | int len = -1; |
641 | if (currentBufPos >= 3) |
||
642 | len = (int)xbee_buf[2] + ((int)xbee_buf[1] << 8); |
||
643 | 409 | emarinel | |
644 | 346 | bcoltin | while (len == -1 //packet length has not been read yet |
645 | || currentBufPos < len + 4)
|
||
646 | { |
||
647 | if (currentBufPos == 3) |
||
648 | { |
||
649 | len = (int)xbee_buf[2] + ((int)xbee_buf[1] << 8); |
||
650 | if (len > 120) |
||
651 | { |
||
652 | WL_DEBUG_PRINT("Packet too large. Probably error in XBee transmission.\n");
|
||
653 | currentBufPos = 0;
|
||
654 | return -1; |
||
655 | } |
||
656 | } |
||
657 | // check if buffer is empty
|
||
658 | if (buffer_first == buffer_last)
|
||
659 | return -1; |
||
660 | xbee_buf[currentBufPos++] = arrival_buf[buffer_first++]; |
||
661 | if (buffer_first == XBEE_BUFFER_SIZE)
|
||
662 | buffer_first = 0;
|
||
663 | } |
||
664 | 409 | emarinel | |
665 | 17 | bcoltin | currentBufPos = 0;
|
666 | 409 | emarinel | |
667 | 346 | bcoltin | if (!xbee_verify_checksum(xbee_buf, len + 4)) |
668 | { |
||
669 | WL_DEBUG_PRINT("XBee checksum failed.\r\n");
|
||
670 | return -1; |
||
671 | } |
||
672 | 17 | bcoltin | |
673 | 346 | bcoltin | //we will take care of the packet
|
674 | if (xbee_handle_packet(xbee_buf + 3, len)) |
||
675 | return -1; |
||
676 | 409 | emarinel | |
677 | 346 | bcoltin | if (dest == NULL) |
678 | return -1; |
||
679 | 409 | emarinel | |
680 | 346 | bcoltin | int i;
|
681 | for (i = 3; i < len + 3; i++) |
||
682 | dest[i - 3] = xbee_buf[i];
|
||
683 | return len;
|
||
684 | 17 | bcoltin | } |
685 | |||
686 | /**
|
||
687 | * Handles modem status packets.
|
||
688 | *
|
||
689 | * @param status the type of status packet received.
|
||
690 | **/
|
||
691 | 346 | bcoltin | void xbee_handle_status(char status) |
692 | { |
||
693 | switch (status)
|
||
694 | { |
||
695 | case 0: |
||
696 | WL_DEBUG_PRINT("XBee hardware reset.\r\n");
|
||
697 | break;
|
||
698 | case 1: |
||
699 | WL_DEBUG_PRINT("Watchdog timer reset.\r\n");
|
||
700 | break;
|
||
701 | case 2: |
||
702 | WL_DEBUG_PRINT("Associated.\r\n");
|
||
703 | break;
|
||
704 | case 3: |
||
705 | WL_DEBUG_PRINT("Disassociated.\r\n");
|
||
706 | break;
|
||
707 | case 4: |
||
708 | WL_DEBUG_PRINT("Synchronization lost.\r\n");
|
||
709 | break;
|
||
710 | case 5: |
||
711 | WL_DEBUG_PRINT("Coordinator realignment.\r\n");
|
||
712 | break;
|
||
713 | case 6: |
||
714 | WL_DEBUG_PRINT("Coordinator started.\r\n");
|
||
715 | break;
|
||
716 | } |
||
717 | 17 | bcoltin | } |
718 | |||
719 | /**
|
||
720 | * Handles AT command response packets.
|
||
721 | * @param command the two character AT command, e.g. MY or ID
|
||
722 | * @param result 0 for success, 1 for an error
|
||
723 | * @param extra the hex value of the requested register
|
||
724 | * @param extraLen the length in bytes of extra
|
||
725 | **/
|
||
726 | void xbee_handle_at_command_response(char* command, char result, |
||
727 | 346 | bcoltin | char* extra, int extraLen) |
728 | { |
||
729 | if (result == 1) |
||
730 | { |
||
731 | WL_DEBUG_PRINT("Error with AT");
|
||
732 | WL_DEBUG_PRINT(command); |
||
733 | WL_DEBUG_PRINT(" packet.\r\n");
|
||
734 | } |
||
735 | WL_DEBUG_PRINT("AT");
|
||
736 | WL_DEBUG_PRINT(command); |
||
737 | WL_DEBUG_PRINT(" command was successful.\r\n");
|
||
738 | 409 | emarinel | |
739 | 346 | bcoltin | if (command[0] == 'I' && command[1] == 'D') |
740 | { |
||
741 | xbee_panID = xbee_pending_panID; |
||
742 | WL_DEBUG_PRINT("PAN ID set to ");
|
||
743 | WL_DEBUG_PRINT_INT(xbee_panID); |
||
744 | WL_DEBUG_PRINT(".\r\n");
|
||
745 | return;
|
||
746 | } |
||
747 | 60 | bcoltin | |
748 | 346 | bcoltin | if (command[0] == 'C' && command[1] == 'H') |
749 | { |
||
750 | xbee_channel = xbee_pending_channel; |
||
751 | WL_DEBUG_PRINT("Channel set to ");
|
||
752 | WL_DEBUG_PRINT_INT(xbee_channel); |
||
753 | WL_DEBUG_PRINT(".\r\n");
|
||
754 | return;
|
||
755 | } |
||
756 | 409 | emarinel | |
757 | 346 | bcoltin | if (command[0] == 'M' && command[1] == 'Y' && extraLen != 0) |
758 | { |
||
759 | xbee_address = 0;
|
||
760 | int i;
|
||
761 | for (i = 0; i < extraLen; i++) |
||
762 | xbee_address = (xbee_address << 8) + extra[i];
|
||
763 | 17 | bcoltin | |
764 | 346 | bcoltin | WL_DEBUG_PRINT("XBee address is ");
|
765 | WL_DEBUG_PRINT_INT(xbee_address); |
||
766 | WL_DEBUG_PRINT(".\r\n");
|
||
767 | 17 | bcoltin | |
768 | 346 | bcoltin | if (xbee_address == 0) |
769 | { |
||
770 | WL_DEBUG_PRINT("XBee 16-bit address must be set using ATMY.\r\n");
|
||
771 | exit(0);
|
||
772 | } |
||
773 | } |
||
774 | 17 | bcoltin | } |
775 | |||
776 | /**
|
||
777 | * Attempts to handle the packet if it is dealt with
|
||
778 | * by the library.
|
||
779 | * We will handle the following packet types:
|
||
780 | * Modem Status
|
||
781 | * AT Command Response
|
||
782 | *
|
||
783 | * @param packet the packet to handle
|
||
784 | * @param len the length of the packet
|
||
785 | 409 | emarinel | *
|
786 | 17 | bcoltin | * @return 1 if we have handled the packet, 0 otherwise
|
787 | */
|
||
788 | 346 | bcoltin | int xbee_handle_packet(char* packet, int len) |
789 | { |
||
790 | char command[3] = {1, 2, 3}; |
||
791 | if (len <= 0) //this should not happend |
||
792 | { |
||
793 | WL_DEBUG_PRINT("Non-positive packet length.\r\n");
|
||
794 | return 0; |
||
795 | } |
||
796 | 409 | emarinel | |
797 | 346 | bcoltin | switch ((unsigned char)packet[0]) //packet type |
798 | { |
||
799 | case XBEE_FRAME_STATUS:
|
||
800 | xbee_handle_status(packet[1]);
|
||
801 | return 1; |
||
802 | case XBEE_FRAME_AT_COMMAND_RESPONSE:
|
||
803 | command[0] = packet[2]; |
||
804 | command[1] = packet[3]; |
||
805 | command[2] = 0; |
||
806 | xbee_handle_at_command_response(command, |
||
807 | packet[4], packet + 5, len - 5); |
||
808 | return 1; |
||
809 | } |
||
810 | return 0; |
||
811 | 17 | bcoltin | } |
812 | |||
813 | /**
|
||
814 | * Sets the personal area network id.
|
||
815 | *
|
||
816 | * @param id the new personal area network (PAN) id
|
||
817 | **/
|
||
818 | 346 | bcoltin | void xbee_set_pan_id(int id) |
819 | { |
||
820 | char s[3]; |
||
821 | s[0] = (id >> 8) & 0xFF; |
||
822 | s[1] = id & 0xFF; |
||
823 | s[2] = 0; |
||
824 | xbee_pending_panID = id; |
||
825 | xbee_send_modify_at_command("ID", s);
|
||
826 | 17 | bcoltin | } |
827 | |||
828 | /**
|
||
829 | * Get the PAN ID for the XBee.
|
||
830 | 409 | emarinel | *
|
831 | 17 | bcoltin | * @return the personal area network id, or
|
832 | * XBEE_PAN_DEFAULT if it has not yet been set.
|
||
833 | **/
|
||
834 | 346 | bcoltin | unsigned int xbee_get_pan_id() |
835 | { |
||
836 | return xbee_panID;
|
||
837 | 17 | bcoltin | } |
838 | |||
839 | /**
|
||
840 | 60 | bcoltin | * Set the channel the XBee is using.
|
841 | *
|
||
842 | 409 | emarinel | * @param channel the channel the XBee will not use,
|
843 | 60 | bcoltin | * between 0x0B and 0x1A
|
844 | *
|
||
845 | * @see xbee_get_channel
|
||
846 | **/
|
||
847 | 346 | bcoltin | void xbee_set_channel(int channel) |
848 | { |
||
849 | if (channel < 0x0B || channel > 0x1A) |
||
850 | { |
||
851 | WL_DEBUG_PRINT("Channel out of range.\r\n");
|
||
852 | return;
|
||
853 | } |
||
854 | char s[3]; |
||
855 | s[0] = channel & 0xFF; |
||
856 | s[1] = 0; |
||
857 | xbee_pending_channel = channel; |
||
858 | xbee_send_modify_at_command("CH", s);
|
||
859 | 60 | bcoltin | } |
860 | |||
861 | /**
|
||
862 | * Returns the channel which the XBee is currently using.
|
||
863 | *
|
||
864 | * @return the channel the XBee is using
|
||
865 | *
|
||
866 | * @see xbee_set_channel
|
||
867 | **/
|
||
868 | 346 | bcoltin | int xbee_get_channel(void) |
869 | { |
||
870 | return xbee_channel;
|
||
871 | 60 | bcoltin | } |
872 | |||
873 | /**
|
||
874 | 17 | bcoltin | * Get the 16-bit address of the XBee.
|
875 | * This is used to specify who to send messages to
|
||
876 | * and who messages are from.
|
||
877 | *
|
||
878 | * @return the 16-bit address of the XBee.
|
||
879 | **/
|
||
880 | 346 | bcoltin | unsigned int xbee_get_address() |
881 | { |
||
882 | return xbee_address;
|
||
883 | 17 | bcoltin | } |
884 | |||
885 | 203 | justin | #ifndef ROBOT
|
886 | 346 | bcoltin | void xbee_set_com_port(char* port) |
887 | { |
||
888 | xbee_com_port = port; |
||
889 | 203 | justin | } |
890 | #endif
|