root / demos / joystick / lib / src / libwireless / xbee.c @ 1736
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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 | 1452 | dsschult | #include <stdio.h> |
46 | #include <stdlib.h> |
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47 | 17 | bcoltin | |
48 | #else
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49 | |||
50 | #include <serial.h> |
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51 | #include <avr/interrupt.h> |
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52 | 1443 | rcahoon | #include <util/delay.h> |
53 | 17 | bcoltin | |
54 | #endif
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55 | |||
56 | #include <string.h> |
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57 | |||
58 | #define XBEE_FRAME_START 0x7E |
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59 | 581 | jknichel | #define XBEE_GET_PACKET_TIMEOUT 1000 |
60 | 17 | bcoltin | |
61 | /*Frame Types*/
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62 | #define XBEE_FRAME_STATUS 0x8A |
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63 | #define XBEE_FRAME_AT_COMMAND 0x08 |
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64 | #define XBEE_FRAME_AT_COMMAND_RESPONSE 0x88 |
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65 | #define XBEE_FRAME_TX_REQUEST_64 0x00 |
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66 | #define XBEE_FRAME_TX_REQUEST_16 0x01 |
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67 | #define XBEE_FRAME_TX_STATUS XBEE_TX_STATUS
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68 | #define XBEE_FRAME_RX_64 0x80 |
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69 | #define XBEE_FRAME_RX_16 XBEE_RX
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70 | |||
71 | /*Internal Function Prototypes*/
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72 | |||
73 | /*I/O Functions*/
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74 | 397 | emarinel | static int xbee_send(char* buf, int size); |
75 | 418 | emarinel | static int xbee_send_string(char* c); |
76 | 17 | bcoltin | |
77 | #ifndef ROBOT
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78 | 418 | emarinel | static int xbee_read(char* buf, int size); |
79 | 17 | bcoltin | #endif
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80 | |||
81 | /*Command Mode Functions
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82 | * Called during initialization.
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83 | */
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84 | 418 | emarinel | static int xbee_enter_command_mode(void); |
85 | static int xbee_exit_command_mode(void); |
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86 | static int xbee_enter_api_mode(void); |
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87 | 1435 | dsschult | static int xbee_exit_api_mode(void); |
88 | 581 | jknichel | static int xbee_wait_for_string(char* s, int len); |
89 | static int xbee_wait_for_ok(void); |
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90 | 17 | bcoltin | |
91 | /*API Mode Functions*/
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92 | |||
93 | 418 | emarinel | static int xbee_handle_packet(char* packet, int len); |
94 | static void xbee_handle_at_command_response(char* command, char result, char* extra, int extraLen); |
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95 | static void xbee_handle_status(char status); |
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96 | static int xbee_verify_checksum(char* packet, int len); |
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97 | static char xbee_compute_checksum(char* packet, int len); |
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98 | static int xbee_send_frame(char* buf, int len); |
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99 | static int xbee_send_read_at_command(char* command); |
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100 | static int xbee_send_modify_at_command(char* command, char* value); |
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101 | 17 | bcoltin | |
102 | /*Global Variables*/
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103 | |||
104 | #ifndef ROBOT
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105 | 399 | emarinel | static char* xbee_com_port = XBEE_PORT_DEFAULT; |
106 | static int xbee_stream; |
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107 | static pthread_t* xbee_listen_thread;
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108 | 17 | bcoltin | #endif
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109 | |||
110 | 336 | bcoltin | // TODO: is this a good size?
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111 | 736 | bcoltin | #define XBEE_BUFFER_SIZE 128 |
112 | #define PACKET_BUFFER_SIZE 108 |
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113 | 336 | bcoltin | // a buffer for data received from the XBee
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114 | char arrival_buf[XBEE_BUFFER_SIZE];
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115 | // location of last unread byte in buffer
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116 | volatile int buffer_last = 0; |
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117 | // first unread byte in buffer
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118 | volatile int buffer_first = 0; |
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119 | 17 | bcoltin | |
120 | 336 | bcoltin | |
121 | 17 | bcoltin | //used to store packets as they are read
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122 | 736 | bcoltin | static char xbee_buf[PACKET_BUFFER_SIZE]; |
123 | 418 | emarinel | static int currentBufPos = 0; |
124 | 17 | bcoltin | |
125 | //XBee status
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126 | 418 | emarinel | static unsigned int xbee_panID = XBEE_PAN_DEFAULT; |
127 | static unsigned int xbee_pending_panID = XBEE_PAN_DEFAULT; |
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128 | static int xbee_channel = XBEE_CHANNEL_DEFAULT; |
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129 | static int xbee_pending_channel = XBEE_CHANNEL_DEFAULT; |
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130 | 581 | jknichel | static volatile unsigned int xbee_address = 0; |
131 | 17 | bcoltin | |
132 | /*Function Implementations*/
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133 | |||
134 | #ifdef ROBOT
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135 | |||
136 | /**
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137 | * Interrupt for the robot. Adds bytes received from the xbee
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138 | 336 | bcoltin | * to the buffer.
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139 | 17 | bcoltin | **/
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140 | 86 | bcoltin | #ifndef FIREFLY
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141 | 346 | bcoltin | ISR(USART1_RX_vect) |
142 | { |
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143 | char c = UDR1;
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144 | arrival_buf[buffer_last] = c; |
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145 | int t = buffer_last + 1; |
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146 | if (t == XBEE_BUFFER_SIZE)
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147 | t = 0;
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148 | if (t == buffer_first)
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149 | { |
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150 | 736 | bcoltin | WL_DEBUG_PRINT("\nOut of space in buffer.\n");
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151 | 346 | bcoltin | } |
152 | buffer_last = t; |
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153 | 17 | bcoltin | } |
154 | 86 | bcoltin | #else
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155 | 346 | bcoltin | SIGNAL(SIG_USART0_RECV) |
156 | { |
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157 | char c = UDR0;
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158 | arrival_buf[buffer_last] = c; |
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159 | int t = buffer_last + 1; |
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160 | if (t == XBEE_BUFFER_SIZE)
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161 | t = 0;
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162 | if (t == buffer_first)
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163 | { |
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164 | WL_DEBUG_PRINT("Out of space in buffer.\n");
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165 | } |
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166 | buffer_last = t; |
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167 | 86 | bcoltin | } |
168 | #endif
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169 | 17 | bcoltin | |
170 | #else
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171 | |||
172 | 418 | emarinel | // Computer code
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173 | |||
174 | 17 | bcoltin | /**
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175 | * Thread that listens to the xbee.
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176 | **/
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177 | 418 | emarinel | static void* listen_to_xbee(void* x) |
178 | 346 | bcoltin | { |
179 | char c;
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180 | while (1) |
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181 | { |
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182 | 418 | emarinel | if (xbee_read(&c, 1) != 0) { |
183 | 736 | bcoltin | WL_DEBUG_PRINT("xbee_read failed.\n");
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184 | 418 | emarinel | return NULL; |
185 | } |
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186 | 717 | jknichel | |
187 | 346 | bcoltin | arrival_buf[buffer_last] = c; |
188 | int t = buffer_last + 1; |
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189 | if (t == XBEE_BUFFER_SIZE)
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190 | t = 0;
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191 | if (t == buffer_first)
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192 | { |
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193 | WL_DEBUG_PRINT("Out of space in buffer.\n");
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194 | } |
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195 | buffer_last = t; |
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196 | 409 | emarinel | |
197 | usleep(1000);
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198 | 346 | bcoltin | } |
199 | 418 | emarinel | |
200 | return NULL; |
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201 | 17 | bcoltin | } |
202 | |||
203 | #endif
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204 | |||
205 | /**
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206 | * Initializes the XBee library so that other functions may be used.
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207 | **/
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208 | 399 | emarinel | int xbee_lib_init()
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209 | 346 | bcoltin | { |
210 | 744 | bcoltin | WL_DEBUG_PRINT("in xbee_init\n");
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211 | 581 | jknichel | #ifdef ROBOT
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212 | 17 | bcoltin | |
213 | 346 | bcoltin | //enable the receiving interrupt
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214 | 412 | emarinel | #ifdef FIREFLY
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215 | 346 | bcoltin | UCSR0B |= _BV(RXCIE) | _BV(RXEN); |
216 | 412 | emarinel | #else
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217 | 887 | bcoltin | #ifdef BAYBOARD
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218 | UCSR1B |= _BV(RXCIE1); |
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219 | #else
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220 | 346 | bcoltin | UCSR1B |= _BV(RXCIE); |
221 | 412 | emarinel | #endif
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222 | 887 | bcoltin | #endif
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223 | 346 | bcoltin | sei(); |
224 | 412 | emarinel | #else
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225 | 346 | bcoltin | xbee_stream = open(xbee_com_port, O_RDWR); |
226 | if (xbee_stream == -1/* || lockf(xbee_stream, F_TEST, 0) != 0*/) |
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227 | { |
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228 | 736 | bcoltin | WL_DEBUG_PRINT("Failed to open connection to XBee on port ");
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229 | WL_DEBUG_PRINT_INT(xbee_com_port); |
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230 | WL_DEBUG_PRINT(".\n");
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231 | 346 | bcoltin | return -1; |
232 | 581 | jknichel | } else {
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233 | 736 | bcoltin | WL_DEBUG_PRINT("Successfully opened connection to XBee on port ");
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234 | WL_DEBUG_PRINT_INT(xbee_com_port); |
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235 | WL_DEBUG_PRINT(".\n");
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236 | 346 | bcoltin | } |
237 | 409 | emarinel | |
238 | 346 | bcoltin | // set baud rate, etc. correctly
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239 | struct termios options;
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240 | 309 | emarinel | |
241 | 346 | bcoltin | tcgetattr(xbee_stream, &options); |
242 | cfsetispeed(&options, B9600); |
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243 | cfsetospeed(&options, B9600); |
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244 | options.c_iflag &= ~ICRNL; |
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245 | options.c_oflag &= ~OCRNL; |
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246 | options.c_cflag |= (CLOCAL | CREAD); |
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247 | options.c_cflag &= ~PARENB; |
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248 | options.c_cflag &= ~CSTOPB; |
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249 | options.c_cflag &= ~CSIZE; |
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250 | options.c_cflag |= CS8; |
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251 | options.c_lflag &= ~ICANON; |
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252 | options.c_cc[VMIN] = 1;
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253 | options.c_cc[VTIME] = 50;
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254 | 309 | emarinel | |
255 | 346 | bcoltin | if (tcsetattr(xbee_stream, TCSANOW, &options))
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256 | { |
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257 | 736 | bcoltin | WL_DEBUG_PRINT("Error setting attributes.\n");
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258 | 346 | bcoltin | return -1; |
259 | } |
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260 | 309 | emarinel | |
261 | 409 | emarinel | xbee_listen_thread = (pthread_t*)malloc(sizeof(pthread_t));
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262 | 346 | bcoltin | if (xbee_listen_thread == NULL) |
263 | { |
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264 | 736 | bcoltin | WL_DEBUG_PRINT("Malloc failed.\n");
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265 | 346 | bcoltin | return -1; |
266 | } |
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267 | 409 | emarinel | |
268 | int ret = pthread_create(xbee_listen_thread, NULL, listen_to_xbee, NULL); |
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269 | 346 | bcoltin | if (ret)
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270 | { |
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271 | 736 | bcoltin | WL_DEBUG_PRINT("Failed to create listener thread.\n");
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272 | 346 | bcoltin | return -1; |
273 | } |
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274 | 412 | emarinel | #endif
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275 | 409 | emarinel | |
276 | 744 | bcoltin | WL_DEBUG_PRINT("Entering command mode.\n");
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277 | 613 | jknichel | |
278 | 418 | emarinel | if (xbee_enter_command_mode() != 0) { |
279 | return -1; |
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280 | } |
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281 | 409 | emarinel | |
282 | 744 | bcoltin | WL_DEBUG_PRINT("Entered command mode.\n");
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283 | |||
284 | 418 | emarinel | if (xbee_enter_api_mode() != 0) { |
285 | return -1; |
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286 | } |
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287 | |||
288 | 744 | bcoltin | WL_DEBUG_PRINT("Entered api mode.\n");
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289 | |||
290 | 418 | emarinel | if (xbee_exit_command_mode() != 0) { |
291 | 931 | tachim | return -1; |
292 | 418 | emarinel | } |
293 | 931 | tachim | |
294 | 744 | bcoltin | WL_DEBUG_PRINT("Left command mode.\n");
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295 | |||
296 | 418 | emarinel | if (xbee_send_read_at_command("MY")) { |
297 | return -1; |
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298 | } |
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299 | 744 | bcoltin | WL_DEBUG_PRINT("Getting ATMY address.\n");
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300 | 418 | emarinel | |
301 | 581 | jknichel | #ifndef ROBOT
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302 | int i;
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303 | for (i = 0; xbee_address == 0 && i < XBEE_GET_PACKET_TIMEOUT; i++) { |
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304 | ret = xbee_get_packet(NULL);
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305 | |||
306 | usleep(1000);
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307 | 931 | tachim | |
308 | /* if (ret == -1) { */
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309 | /* WL_DEBUG_PRINT("xbee_get_packet(NULL) failed.\n"); */
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310 | /* return -1; */
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311 | /* } */
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312 | 581 | jknichel | } |
313 | #else
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314 | 346 | bcoltin | //wait to return until the address is set
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315 | 717 | jknichel | //TODO: this shouldn't wait indefinitely. There should be some sort of reasonable timeout
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316 | // so if the address is never set right, an error can be returned instead of having the
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317 | // robot hang forever
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318 | 581 | jknichel | while (xbee_address == 0) { |
319 | xbee_get_packet(NULL);
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320 | } |
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321 | #endif
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322 | 744 | bcoltin | WL_DEBUG_PRINT("Got ATMY address.\n");
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323 | 309 | emarinel | |
324 | 581 | jknichel | #ifndef ROBOT
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325 | if (i == XBEE_GET_PACKET_TIMEOUT) { // We timed-out. |
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326 | |||
327 | 736 | bcoltin | WL_DEBUG_PRINT("xbee_get_packet timed out.\n");
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328 | 581 | jknichel | return -1; |
329 | } else {
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330 | return 0; |
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331 | } |
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332 | #else
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333 | 346 | bcoltin | return 0; |
334 | 581 | jknichel | #endif
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335 | 17 | bcoltin | } |
336 | |||
337 | /**
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338 | * Call when finished using the XBee library. This releases
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339 | * all sued resources.
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340 | **/
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341 | 346 | bcoltin | void xbee_terminate()
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342 | { |
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343 | #ifndef ROBOT
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344 | pthread_cancel(*xbee_listen_thread); |
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345 | 1428 | rcahoon | pthread_join(*xbee_listen_thread, NULL);
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346 | 346 | bcoltin | free(xbee_listen_thread); |
347 | lockf(xbee_stream, F_ULOCK, 0);
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348 | close(xbee_stream); |
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349 | 1435 | dsschult | #else
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350 | xbee_exit_api_mode(); |
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351 | 346 | bcoltin | #endif
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352 | 17 | bcoltin | } |
353 | |||
354 | /**
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355 | * Send a buffer buf of size bytes to the XBee.
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356 | 409 | emarinel | *
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357 | 17 | bcoltin | * @param buf the buffer of data to send
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358 | * @param size the number of bytes to send
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359 | **/
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360 | 418 | emarinel | static int xbee_send(char* buf, int size) |
361 | 346 | bcoltin | { |
362 | 418 | emarinel | #ifdef ROBOT
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363 | 346 | bcoltin | int i;
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364 | 418 | emarinel | for (i = 0; i < size; i++) { |
365 | 346 | bcoltin | xbee_putc(buf[i]); |
366 | 418 | emarinel | } |
367 | |||
368 | return 0; |
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369 | |||
370 | #else
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371 | |||
372 | 346 | bcoltin | int ret = write(xbee_stream, buf, size);
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373 | //success
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374 | if (ret == size)
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375 | 397 | emarinel | return 0; |
376 | 346 | bcoltin | if (ret == -1) |
377 | { |
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378 | //interrupted by system signal, probably timer interrupt.
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379 | //just try again
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380 | if (errno == 4) |
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381 | { |
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382 | 397 | emarinel | return xbee_send(buf, size);
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383 | 346 | bcoltin | } |
384 | 755 | gtress | WL_DEBUG_PRINT("Failed to write to xbee\r\n");
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385 | 397 | emarinel | return -1; |
386 | 346 | bcoltin | } |
387 | 17 | bcoltin | |
388 | 346 | bcoltin | //write was interrupted after writing ret bytes
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389 | 418 | emarinel | return xbee_send(buf + ret, size - ret);
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390 | #endif
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391 | 17 | bcoltin | } |
392 | |||
393 | /**
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394 | * Sends a string to the XBee.
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395 | *
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396 | * @param c the string to send to the XBEE
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397 | **/
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398 | 418 | emarinel | static int xbee_send_string(char* c) |
399 | 346 | bcoltin | { |
400 | 418 | emarinel | return xbee_send(c, strlen(c));
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401 | 17 | bcoltin | } |
402 | |||
403 | #ifndef ROBOT
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404 | 418 | emarinel | static int xbee_read(char* buf, int size) |
405 | 346 | bcoltin | { |
406 | 418 | emarinel | if (read(xbee_stream, buf, size) == -1) { |
407 | 736 | bcoltin | WL_DEBUG_PRINT("Failed to read from xbee.\r\n");
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408 | 418 | emarinel | return -1; |
409 | } |
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410 | |||
411 | return 0; |
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412 | 17 | bcoltin | } |
413 | #endif
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414 | |||
415 | /**
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416 | * Enter into command mode.
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417 | **/
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418 | 418 | emarinel | static int xbee_enter_command_mode() |
419 | 346 | bcoltin | { |
420 | 418 | emarinel | if (xbee_send_string("+++") != 0) { |
421 | return -1; |
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422 | } |
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423 | |||
424 | 581 | jknichel | if (xbee_wait_for_ok() != 0) { |
425 | return -1; |
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426 | 736 | bcoltin | } |
427 | 581 | jknichel | return 0; |
428 | 17 | bcoltin | } |
429 | |||
430 | /**
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431 | * Exit from command mode.
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432 | **/
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433 | 418 | emarinel | static int xbee_exit_command_mode() |
434 | 346 | bcoltin | { |
435 | 418 | emarinel | if (xbee_send_string("ATCN\r") != 0) { |
436 | return -1; |
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437 | } |
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438 | |||
439 | 346 | bcoltin | xbee_wait_for_ok(); |
440 | 418 | emarinel | |
441 | return 0; |
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442 | 17 | bcoltin | } |
443 | |||
444 | /**
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445 | * Enter API mode.
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446 | **/
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447 | 418 | emarinel | static int xbee_enter_api_mode() |
448 | 346 | bcoltin | { |
449 | 418 | emarinel | if (xbee_send_string("ATAP 1\r") != 0) { |
450 | return -1; |
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451 | } |
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452 | 346 | bcoltin | xbee_wait_for_ok(); |
453 | 418 | emarinel | |
454 | return 0; |
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455 | 17 | bcoltin | } |
456 | |||
457 | /**
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458 | 1435 | dsschult | * Exit API mode.
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459 | **/
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460 | static int xbee_exit_api_mode() |
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461 | { |
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462 | if (xbee_send_modify_at_command("AP","0") != 0) { |
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463 | return -1; |
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464 | } |
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465 | |||
466 | return 0; |
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467 | } |
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468 | |||
469 | /**
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470 | 17 | bcoltin | * Wait until the string "OK\r" is received from the XBee.
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471 | **/
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472 | 581 | jknichel | static int xbee_wait_for_ok() |
473 | 346 | bcoltin | { |
474 | 581 | jknichel | return xbee_wait_for_string("OK\r", 3); |
475 | 17 | bcoltin | } |
476 | |||
477 | /**
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478 | * Delay until the specified string is received from
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479 | * the XBee. Discards all other XBee data.
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480 | *
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481 | * @param s the string to receive
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482 | * @param len the length of the string
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483 | **/
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484 | 581 | jknichel | static int xbee_wait_for_string(char* s, int len) |
485 | 346 | bcoltin | { |
486 | 412 | emarinel | char* curr = s;
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487 | while (curr - s < len) {
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488 | // check if buffer is empty
|
||
489 | if (buffer_last != buffer_first) {
|
||
490 | char c = arrival_buf[buffer_first++];
|
||
491 | if (buffer_first == XBEE_BUFFER_SIZE) {
|
||
492 | buffer_first = 0;
|
||
493 | } |
||
494 | 409 | emarinel | |
495 | 412 | emarinel | if (c == *curr) {
|
496 | curr++; |
||
497 | } else {
|
||
498 | 581 | jknichel | #ifndef ROBOT
|
499 | 613 | jknichel | //return -1; // Computer is less forgiving.
|
500 | curr = s; |
||
501 | 581 | jknichel | #else
|
502 | curr = s; |
||
503 | #endif
|
||
504 | 412 | emarinel | } |
505 | 581 | jknichel | } // else buffer is empty.
|
506 | 409 | emarinel | |
507 | 412 | emarinel | #ifndef ROBOT
|
508 | 581 | jknichel | usleep(100);
|
509 | 412 | emarinel | #endif
|
510 | } |
||
511 | 581 | jknichel | |
512 | return 0; |
||
513 | 17 | bcoltin | } |
514 | |||
515 | /**
|
||
516 | * Verifies that the packets checksum is correct.
|
||
517 | * (If the checksum is correct, the sum of the bytes
|
||
518 | * is 0xFF.)
|
||
519 | *
|
||
520 | * @param packet the packet received. This includes the first
|
||
521 | * three bytes, which are header information from the XBee.
|
||
522 | *
|
||
523 | * @param len The length of the packet received from the XBee
|
||
524 | *
|
||
525 | * @return 0 if the checksum is incorrect, nonzero
|
||
526 | * otherwise
|
||
527 | **/
|
||
528 | 346 | bcoltin | int xbee_verify_checksum(char* packet, int len) |
529 | { |
||
530 | unsigned char sum = 0; |
||
531 | int i;
|
||
532 | for (i = 3; i < len; i++) |
||
533 | sum += (unsigned char)packet[i]; |
||
534 | return sum == 0xFF; |
||
535 | 17 | bcoltin | } |
536 | |||
537 | /**
|
||
538 | * Returns the checksum of the given packet.
|
||
539 | *
|
||
540 | * @param buf the data for the packet to send
|
||
541 | * @param len the length of the packet in bytes
|
||
542 | *
|
||
543 | * @return the checksum of the packet, which will
|
||
544 | * become the last byte sent in the packet
|
||
545 | **/
|
||
546 | 346 | bcoltin | char xbee_compute_checksum(char* buf, int len) |
547 | { |
||
548 | int i;
|
||
549 | unsigned char sum = 0; |
||
550 | for (i = 0; i < len; i++) |
||
551 | sum += (unsigned char)buf[i]; |
||
552 | return 0xFF - sum; |
||
553 | 17 | bcoltin | } |
554 | |||
555 | /**
|
||
556 | * Adds header information and checksum to the given
|
||
557 | * packet and sends it. Header information includes
|
||
558 | * XBEE_FRAME_START and the packet length, as two bytes.
|
||
559 | *
|
||
560 | * @param buf the packet data
|
||
561 | * @param len the size in bytes of the packet data
|
||
562 | *
|
||
563 | **/
|
||
564 | 418 | emarinel | static int xbee_send_frame(char* buf, int len) |
565 | 346 | bcoltin | { |
566 | char prefix[3]; |
||
567 | prefix[0] = XBEE_FRAME_START;
|
||
568 | prefix[1] = (len & 0xFF00) >> 8; |
||
569 | prefix[2] = len & 0xFF; |
||
570 | char checksum = xbee_compute_checksum(buf, len);
|
||
571 | 418 | emarinel | |
572 | if (xbee_send(prefix, 3) != 0) { |
||
573 | return -1; |
||
574 | } |
||
575 | 581 | jknichel | |
576 | 418 | emarinel | if (xbee_send(buf, len) != 0) { |
577 | return -1; |
||
578 | } |
||
579 | |||
580 | if (xbee_send(&checksum, 1) != 0) { |
||
581 | return -1; |
||
582 | } |
||
583 | |||
584 | return 0; |
||
585 | 17 | bcoltin | } |
586 | |||
587 | /**
|
||
588 | 1443 | rcahoon | * Resets the XBee Modem (including baud rate when on robot)
|
589 | *
|
||
590 | * Used for launching bootloader
|
||
591 | **/
|
||
592 | int xbee_reset(void) |
||
593 | { |
||
594 | #ifdef ROBOT
|
||
595 | xbee_send_modify_at_command("BD", "3"); |
||
596 | #endif
|
||
597 | xbee_send_read_at_command("FR");
|
||
598 | // delay 150 ms to wait for reset
|
||
599 | #ifndef ROBOT
|
||
600 | usleep(150000);
|
||
601 | #else
|
||
602 | _delay_ms(150);
|
||
603 | #endif
|
||
604 | |||
605 | return 0; |
||
606 | } |
||
607 | |||
608 | /**
|
||
609 | 17 | bcoltin | * Sends an AT command to read a parameter.
|
610 | *
|
||
611 | * @param command the AT command to send. For exmaple,
|
||
612 | * use ID to read the PAN ID and MY to return the XBee ID.
|
||
613 | * See the XBee reference guide for a complete listing.
|
||
614 | **/
|
||
615 | 418 | emarinel | static int xbee_send_read_at_command(char* command) |
616 | 346 | bcoltin | { |
617 | 418 | emarinel | return xbee_send_modify_at_command(command, NULL); |
618 | 17 | bcoltin | } |
619 | |||
620 | /**
|
||
621 | * Sends the given AT command.
|
||
622 | *
|
||
623 | * @param command the AT command to send (e.g., MY, ID)
|
||
624 | * @param value the value to pass as a parameter
|
||
625 | * (or NULL if there is no parameter)
|
||
626 | **/
|
||
627 | 418 | emarinel | static int xbee_send_modify_at_command(char* command, char* value) |
628 | 346 | bcoltin | { |
629 | char buf[16]; |
||
630 | int i;
|
||
631 | 409 | emarinel | |
632 | 346 | bcoltin | buf[0] = XBEE_FRAME_AT_COMMAND;
|
633 | buf[1] = 1; |
||
634 | buf[2] = command[0]; |
||
635 | buf[3] = command[1]; |
||
636 | int valueLen = 0; |
||
637 | if (value != NULL) |
||
638 | { |
||
639 | valueLen = strlen(value); |
||
640 | if (valueLen > 8) |
||
641 | { |
||
642 | WL_DEBUG_PRINT("AT Command too large.\r\n");
|
||
643 | 418 | emarinel | return -1; |
644 | 346 | bcoltin | } |
645 | 418 | emarinel | |
646 | for (i = 0; i < valueLen; i++) { |
||
647 | 346 | bcoltin | buf[4 + i] = value[i];
|
648 | 418 | emarinel | } |
649 | 346 | bcoltin | } |
650 | 418 | emarinel | |
651 | return xbee_send_frame(buf, 4 + valueLen); |
||
652 | 17 | bcoltin | } |
653 | |||
654 | /**
|
||
655 | * Send the specified packet.
|
||
656 | 409 | emarinel | *
|
657 | 17 | bcoltin | * @param packet the packet data to send
|
658 | * @param len the number of bytes in the packet
|
||
659 | 409 | emarinel | *
|
660 | 17 | bcoltin | * @param dest the ID of the XBee to send the packet to,
|
661 | * or XBEE_BROADCAST to send the message to all robots
|
||
662 | * in the PAN.
|
||
663 | 409 | emarinel | *
|
664 | 17 | bcoltin | * @param options a combination of the flags
|
665 | 409 | emarinel | * XBEE_OPTIONS_NONE, XBEE_OPTIONS_DISABLE_RESPONSE and
|
666 | 17 | bcoltin | * XBEE_OPTIONS_BROADCAST_ALL_PANS
|
667 | *
|
||
668 | * @param frame the frame number to associate this packet
|
||
669 | * with. This will be used to identify the response when
|
||
670 | * the XBee alerts us as to whether or not our message
|
||
671 | * was received.
|
||
672 | **/
|
||
673 | 397 | emarinel | int xbee_send_packet(char* packet, int len, int dest, char options, char frame) |
674 | 346 | bcoltin | { |
675 | char buf[5]; |
||
676 | char prefix[3]; |
||
677 | int i;
|
||
678 | unsigned char checksum = 0; |
||
679 | 17 | bcoltin | |
680 | 346 | bcoltin | if (len > 100) |
681 | { |
||
682 | WL_DEBUG_PRINT("Packet is too large.\r\n");
|
||
683 | 397 | emarinel | return -1; |
684 | 346 | bcoltin | } |
685 | 17 | bcoltin | |
686 | 346 | bcoltin | //data for sending request
|
687 | buf[0] = XBEE_FRAME_TX_REQUEST_16;
|
||
688 | buf[1] = frame;
|
||
689 | buf[2] = (dest >> 8) & 0xFF; |
||
690 | buf[3] = dest & 0xFF; |
||
691 | buf[4] = options;
|
||
692 | 17 | bcoltin | |
693 | 346 | bcoltin | //packet prefix, do this here so we don't need an extra buffer
|
694 | prefix[0] = XBEE_FRAME_START;
|
||
695 | prefix[1] = ((5 + len) & 0xFF00) >> 8; |
||
696 | prefix[2] = (5 + len) & 0xFF; |
||
697 | 17 | bcoltin | |
698 | 346 | bcoltin | for (i = 0; i < 5; i++) |
699 | checksum += (unsigned char)buf[i]; |
||
700 | for (i = 0; i < len; i++) |
||
701 | checksum += (unsigned char)packet[i]; |
||
702 | checksum = 0xFF - checksum;
|
||
703 | 397 | emarinel | |
704 | if (xbee_send(prefix, 3) != 0) { |
||
705 | return -1; |
||
706 | } |
||
707 | |||
708 | if (xbee_send(buf, 5) != 0) { |
||
709 | return -1; |
||
710 | } |
||
711 | |||
712 | if (xbee_send(packet, len) != 0) { |
||
713 | return -1; |
||
714 | } |
||
715 | |||
716 | if (xbee_send((char*)&checksum, 1) != 0) { |
||
717 | return -1; |
||
718 | } |
||
719 | |||
720 | return 0; |
||
721 | 17 | bcoltin | } |
722 | |||
723 | /**
|
||
724 | * Reads a packet received from the XBee. This function
|
||
725 | * is non-blocking. The resulting packet is stored in dest.
|
||
726 | * Only returns transmission response packets and
|
||
727 | * received packets. The returned packet does not include
|
||
728 | * header information or the checksum. This method also
|
||
729 | * handles special packets dealt with by the XBee library,
|
||
730 | * and so should be called frequently while the XBee is in
|
||
731 | * use.<br><br>
|
||
732 | *
|
||
733 | * The first byte of the packet will be either
|
||
734 | * XBEE_TX_STATUS or XBEE_RX to indicated
|
||
735 | 409 | emarinel | * a response to a sent message or a received message,
|
736 | 17 | bcoltin | * respectively.<br><br>
|
737 | *
|
||
738 | * For a status response packet:<br>
|
||
739 | * The first byte will be XBEE_TX_STATUS.<br>
|
||
740 | * The second byte will be the frame number.<br>
|
||
741 | * The third byte will be the result. 0 indicates success,
|
||
742 | 409 | emarinel | * and nonzero indicates that an error ocurred in
|
743 | 17 | bcoltin | * transmitting the packet.<br><br>
|
744 | *
|
||
745 | * For a received packet:<br>
|
||
746 | * The first byte will be XBEE_RX.<br>
|
||
747 | * The second and third bytes will be the 16-bit
|
||
748 | * address of the packet's sender.<br>
|
||
749 | * The fourth byte is the signal strength.<br>
|
||
750 | * The fifth byte is 1 if the packet were sent to
|
||
751 | * a specific address, and 2 if it is a broadcast packet.<br><br>
|
||
752 | 409 | emarinel | *
|
753 | 17 | bcoltin | * @param dest set to the packet data
|
754 | * @return the length of the packet, or -1 if no packet
|
||
755 | * is available
|
||
756 | **/
|
||
757 | 346 | bcoltin | int xbee_get_packet(unsigned char* dest) |
758 | { |
||
759 | 931 | tachim | int ret;
|
760 | 346 | bcoltin | //start reading a packet with XBEE_FRAME_START
|
761 | if (currentBufPos == 0) |
||
762 | { |
||
763 | do
|
||
764 | { |
||
765 | if (buffer_first == XBEE_BUFFER_SIZE)
|
||
766 | buffer_first = 0;
|
||
767 | // check if buffer is empty
|
||
768 | 581 | jknichel | if (buffer_first == buffer_last) {
|
769 | 887 | bcoltin | return -1; |
770 | 581 | jknichel | } |
771 | 418 | emarinel | } while (arrival_buf[buffer_first++] != XBEE_FRAME_START);
|
772 | |||
773 | if (buffer_first == XBEE_BUFFER_SIZE) {
|
||
774 | buffer_first = 0;
|
||
775 | 346 | bcoltin | } |
776 | xbee_buf[0] = XBEE_FRAME_START;
|
||
777 | currentBufPos++; |
||
778 | } |
||
779 | 17 | bcoltin | |
780 | 346 | bcoltin | int len = -1; |
781 | 418 | emarinel | if (currentBufPos >= 3) { |
782 | 346 | bcoltin | len = (int)xbee_buf[2] + ((int)xbee_buf[1] << 8); |
783 | 418 | emarinel | } |
784 | 409 | emarinel | |
785 | 346 | bcoltin | while (len == -1 //packet length has not been read yet |
786 | 418 | emarinel | || currentBufPos < len + 4)
|
787 | 346 | bcoltin | { |
788 | if (currentBufPos == 3) |
||
789 | { |
||
790 | len = (int)xbee_buf[2] + ((int)xbee_buf[1] << 8); |
||
791 | if (len > 120) |
||
792 | { |
||
793 | WL_DEBUG_PRINT("Packet too large. Probably error in XBee transmission.\n");
|
||
794 | currentBufPos = 0;
|
||
795 | return -1; |
||
796 | } |
||
797 | } |
||
798 | 418 | emarinel | |
799 | 346 | bcoltin | // check if buffer is empty
|
800 | 418 | emarinel | if (buffer_first == buffer_last) {
|
801 | 887 | bcoltin | return -1; |
802 | 418 | emarinel | } |
803 | 346 | bcoltin | xbee_buf[currentBufPos++] = arrival_buf[buffer_first++]; |
804 | 418 | emarinel | if (buffer_first == XBEE_BUFFER_SIZE) {
|
805 | 346 | bcoltin | buffer_first = 0;
|
806 | 418 | emarinel | } |
807 | 346 | bcoltin | } |
808 | 409 | emarinel | |
809 | 17 | bcoltin | currentBufPos = 0;
|
810 | 409 | emarinel | |
811 | 346 | bcoltin | if (!xbee_verify_checksum(xbee_buf, len + 4)) |
812 | { |
||
813 | WL_DEBUG_PRINT("XBee checksum failed.\r\n");
|
||
814 | return -1; |
||
815 | } |
||
816 | 17 | bcoltin | |
817 | 346 | bcoltin | //we will take care of the packet
|
818 | 931 | tachim | |
819 | ret = xbee_handle_packet(xbee_buf+3, len);
|
||
820 | if (ret == 1) { |
||
821 | return 3; |
||
822 | 418 | emarinel | } |
823 | 931 | tachim | |
824 | 418 | emarinel | if (dest == NULL) { |
825 | 887 | bcoltin | return -1; |
826 | 418 | emarinel | } |
827 | 409 | emarinel | |
828 | 346 | bcoltin | int i;
|
829 | 418 | emarinel | for (i = 3; i < len + 3; i++) { |
830 | 346 | bcoltin | dest[i - 3] = xbee_buf[i];
|
831 | 418 | emarinel | } |
832 | 346 | bcoltin | return len;
|
833 | 17 | bcoltin | } |
834 | |||
835 | /**
|
||
836 | * Handles modem status packets.
|
||
837 | *
|
||
838 | * @param status the type of status packet received.
|
||
839 | **/
|
||
840 | 346 | bcoltin | void xbee_handle_status(char status) |
841 | { |
||
842 | switch (status)
|
||
843 | { |
||
844 | case 0: |
||
845 | WL_DEBUG_PRINT("XBee hardware reset.\r\n");
|
||
846 | break;
|
||
847 | case 1: |
||
848 | WL_DEBUG_PRINT("Watchdog timer reset.\r\n");
|
||
849 | break;
|
||
850 | case 2: |
||
851 | WL_DEBUG_PRINT("Associated.\r\n");
|
||
852 | break;
|
||
853 | case 3: |
||
854 | WL_DEBUG_PRINT("Disassociated.\r\n");
|
||
855 | break;
|
||
856 | case 4: |
||
857 | WL_DEBUG_PRINT("Synchronization lost.\r\n");
|
||
858 | break;
|
||
859 | case 5: |
||
860 | WL_DEBUG_PRINT("Coordinator realignment.\r\n");
|
||
861 | break;
|
||
862 | case 6: |
||
863 | WL_DEBUG_PRINT("Coordinator started.\r\n");
|
||
864 | break;
|
||
865 | } |
||
866 | 17 | bcoltin | } |
867 | |||
868 | /**
|
||
869 | * Handles AT command response packets.
|
||
870 | * @param command the two character AT command, e.g. MY or ID
|
||
871 | * @param result 0 for success, 1 for an error
|
||
872 | * @param extra the hex value of the requested register
|
||
873 | * @param extraLen the length in bytes of extra
|
||
874 | **/
|
||
875 | 418 | emarinel | static void xbee_handle_at_command_response(char* command, char result, char* extra, int extraLen) |
876 | 346 | bcoltin | { |
877 | if (result == 1) |
||
878 | { |
||
879 | WL_DEBUG_PRINT("Error with AT");
|
||
880 | WL_DEBUG_PRINT(command); |
||
881 | WL_DEBUG_PRINT(" packet.\r\n");
|
||
882 | } |
||
883 | WL_DEBUG_PRINT("AT");
|
||
884 | WL_DEBUG_PRINT(command); |
||
885 | WL_DEBUG_PRINT(" command was successful.\r\n");
|
||
886 | 409 | emarinel | |
887 | 346 | bcoltin | if (command[0] == 'I' && command[1] == 'D') |
888 | { |
||
889 | xbee_panID = xbee_pending_panID; |
||
890 | WL_DEBUG_PRINT("PAN ID set to ");
|
||
891 | WL_DEBUG_PRINT_INT(xbee_panID); |
||
892 | WL_DEBUG_PRINT(".\r\n");
|
||
893 | return;
|
||
894 | } |
||
895 | 60 | bcoltin | |
896 | 346 | bcoltin | if (command[0] == 'C' && command[1] == 'H') |
897 | { |
||
898 | xbee_channel = xbee_pending_channel; |
||
899 | WL_DEBUG_PRINT("Channel set to ");
|
||
900 | WL_DEBUG_PRINT_INT(xbee_channel); |
||
901 | WL_DEBUG_PRINT(".\r\n");
|
||
902 | return;
|
||
903 | } |
||
904 | 409 | emarinel | |
905 | 346 | bcoltin | if (command[0] == 'M' && command[1] == 'Y' && extraLen != 0) |
906 | { |
||
907 | xbee_address = 0;
|
||
908 | int i;
|
||
909 | 418 | emarinel | for (i = 0; i < extraLen; i++) { |
910 | 346 | bcoltin | xbee_address = (xbee_address << 8) + extra[i];
|
911 | 418 | emarinel | } |
912 | 17 | bcoltin | |
913 | 346 | bcoltin | WL_DEBUG_PRINT("XBee address is ");
|
914 | WL_DEBUG_PRINT_INT(xbee_address); |
||
915 | WL_DEBUG_PRINT(".\r\n");
|
||
916 | 17 | bcoltin | |
917 | 346 | bcoltin | if (xbee_address == 0) |
918 | { |
||
919 | WL_DEBUG_PRINT("XBee 16-bit address must be set using ATMY.\r\n");
|
||
920 | 736 | bcoltin | #ifndef ROBOT
|
921 | 346 | bcoltin | exit(0);
|
922 | 736 | bcoltin | #endif
|
923 | 346 | bcoltin | } |
924 | } |
||
925 | 17 | bcoltin | } |
926 | |||
927 | /**
|
||
928 | * Attempts to handle the packet if it is dealt with
|
||
929 | * by the library.
|
||
930 | * We will handle the following packet types:
|
||
931 | * Modem Status
|
||
932 | * AT Command Response
|
||
933 | *
|
||
934 | * @param packet the packet to handle
|
||
935 | * @param len the length of the packet
|
||
936 | 409 | emarinel | *
|
937 | 17 | bcoltin | * @return 1 if we have handled the packet, 0 otherwise
|
938 | */
|
||
939 | 418 | emarinel | static int xbee_handle_packet(char* packet, int len) |
940 | 346 | bcoltin | { |
941 | 613 | jknichel | |
942 | 346 | bcoltin | char command[3] = {1, 2, 3}; |
943 | if (len <= 0) //this should not happend |
||
944 | { |
||
945 | WL_DEBUG_PRINT("Non-positive packet length.\r\n");
|
||
946 | return 0; |
||
947 | } |
||
948 | 409 | emarinel | |
949 | 346 | bcoltin | switch ((unsigned char)packet[0]) //packet type |
950 | { |
||
951 | case XBEE_FRAME_STATUS:
|
||
952 | xbee_handle_status(packet[1]);
|
||
953 | return 1; |
||
954 | case XBEE_FRAME_AT_COMMAND_RESPONSE:
|
||
955 | command[0] = packet[2]; |
||
956 | command[1] = packet[3]; |
||
957 | command[2] = 0; |
||
958 | 418 | emarinel | xbee_handle_at_command_response(command, packet[4], packet + 5, len - 5); |
959 | 346 | bcoltin | return 1; |
960 | } |
||
961 | return 0; |
||
962 | 17 | bcoltin | } |
963 | |||
964 | /**
|
||
965 | * Sets the personal area network id.
|
||
966 | *
|
||
967 | * @param id the new personal area network (PAN) id
|
||
968 | **/
|
||
969 | 418 | emarinel | int xbee_set_pan_id(int id) |
970 | 346 | bcoltin | { |
971 | char s[3]; |
||
972 | s[0] = (id >> 8) & 0xFF; |
||
973 | s[1] = id & 0xFF; |
||
974 | s[2] = 0; |
||
975 | xbee_pending_panID = id; |
||
976 | 418 | emarinel | return xbee_send_modify_at_command("ID", s); |
977 | 17 | bcoltin | } |
978 | |||
979 | /**
|
||
980 | * Get the PAN ID for the XBee.
|
||
981 | 409 | emarinel | *
|
982 | 17 | bcoltin | * @return the personal area network id, or
|
983 | * XBEE_PAN_DEFAULT if it has not yet been set.
|
||
984 | **/
|
||
985 | 346 | bcoltin | unsigned int xbee_get_pan_id() |
986 | { |
||
987 | return xbee_panID;
|
||
988 | 17 | bcoltin | } |
989 | |||
990 | /**
|
||
991 | 60 | bcoltin | * Set the channel the XBee is using.
|
992 | *
|
||
993 | 409 | emarinel | * @param channel the channel the XBee will not use,
|
994 | 60 | bcoltin | * between 0x0B and 0x1A
|
995 | *
|
||
996 | * @see xbee_get_channel
|
||
997 | **/
|
||
998 | 418 | emarinel | int xbee_set_channel(int channel) |
999 | 346 | bcoltin | { |
1000 | if (channel < 0x0B || channel > 0x1A) |
||
1001 | { |
||
1002 | WL_DEBUG_PRINT("Channel out of range.\r\n");
|
||
1003 | 418 | emarinel | return -1; |
1004 | 346 | bcoltin | } |
1005 | 418 | emarinel | |
1006 | 346 | bcoltin | char s[3]; |
1007 | s[0] = channel & 0xFF; |
||
1008 | s[1] = 0; |
||
1009 | xbee_pending_channel = channel; |
||
1010 | 418 | emarinel | |
1011 | return xbee_send_modify_at_command("CH", s); |
||
1012 | 60 | bcoltin | } |
1013 | |||
1014 | /**
|
||
1015 | * Returns the channel which the XBee is currently using.
|
||
1016 | *
|
||
1017 | * @return the channel the XBee is using
|
||
1018 | *
|
||
1019 | * @see xbee_set_channel
|
||
1020 | **/
|
||
1021 | 346 | bcoltin | int xbee_get_channel(void) |
1022 | { |
||
1023 | return xbee_channel;
|
||
1024 | 60 | bcoltin | } |
1025 | |||
1026 | /**
|
||
1027 | 17 | bcoltin | * Get the 16-bit address of the XBee.
|
1028 | * This is used to specify who to send messages to
|
||
1029 | * and who messages are from.
|
||
1030 | *
|
||
1031 | * @return the 16-bit address of the XBee.
|
||
1032 | **/
|
||
1033 | 346 | bcoltin | unsigned int xbee_get_address() |
1034 | { |
||
1035 | return xbee_address;
|
||
1036 | 17 | bcoltin | } |
1037 | |||
1038 | 203 | justin | #ifndef ROBOT
|
1039 | 346 | bcoltin | void xbee_set_com_port(char* port) |
1040 | { |
||
1041 | xbee_com_port = port; |
||
1042 | 203 | justin | } |
1043 | #endif |