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1 | 1432 | dsschult | /**
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2 | * Copyright (c) 2007 Colony Project
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3 | *
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4 | * 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 | *
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13 | * 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 | *
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16 | * 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 | #include <xbee.h> |
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36 | #include <wl_defs.h> |
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37 | |||
38 | #define ROBOT
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39 | #define WL_DEBUG
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40 | #define WL_DEBUG_PRINT( s ) usb_puts( s )
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41 | #define WL_DEBUG_PRINT_INT( i ) usb_puti(i)
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42 | |||
43 | #ifndef ROBOT
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44 | |||
45 | #include <fcntl.h> |
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46 | #include <unistd.h> |
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47 | #include <pthread.h> |
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48 | #include <errno.h> |
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49 | #include <termios.h> |
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50 | |||
51 | #else
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52 | |||
53 | #include <serial.h> |
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54 | #include <avr/interrupt.h> |
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55 | |||
56 | #endif
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57 | |||
58 | #include <stdio.h> |
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59 | #include <stdlib.h> |
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60 | #include <string.h> |
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61 | |||
62 | #define XBEE_FRAME_START 0x7E |
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63 | #define XBEE_GET_PACKET_TIMEOUT 1000 |
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64 | |||
65 | /*Frame Types*/
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66 | #define XBEE_FRAME_STATUS 0x8A |
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67 | #define XBEE_FRAME_AT_COMMAND 0x08 |
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68 | #define XBEE_FRAME_AT_COMMAND_RESPONSE 0x88 |
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69 | #define XBEE_FRAME_TX_REQUEST_64 0x00 |
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70 | #define XBEE_FRAME_TX_REQUEST_16 0x01 |
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71 | #define XBEE_FRAME_TX_STATUS XBEE_TX_STATUS
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72 | #define XBEE_FRAME_RX_64 0x80 |
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73 | #define XBEE_FRAME_RX_16 XBEE_RX
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74 | |||
75 | /*Internal Function Prototypes*/
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76 | |||
77 | /*I/O Functions*/
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78 | static int xbee_send(char* buf, int size); |
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79 | static int xbee_send_string(char* c); |
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80 | |||
81 | #ifndef ROBOT
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82 | static int xbee_read(char* buf, int size); |
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83 | #endif
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84 | |||
85 | /*Command Mode Functions
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86 | * Called during initialization.
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87 | */
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88 | static int xbee_enter_command_mode(void); |
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89 | static int xbee_exit_command_mode(void); |
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90 | static int xbee_enter_api_mode(void); |
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91 | 1437 | dsschult | static int xbee_exit_api_mode(void); |
92 | 1432 | dsschult | static int xbee_wait_for_string(char* s, int len); |
93 | static int xbee_wait_for_ok(void); |
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94 | |||
95 | /*API Mode Functions*/
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96 | |||
97 | static int xbee_handle_packet(char* packet, int len); |
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98 | static void xbee_handle_at_command_response(char* command, char result, char* extra, int extraLen); |
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99 | static void xbee_handle_status(char status); |
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100 | static int xbee_verify_checksum(char* packet, int len); |
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101 | static char xbee_compute_checksum(char* packet, int len); |
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102 | static int xbee_send_frame(char* buf, int len); |
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103 | int xbee_send_read_at_command(char* command); |
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104 | static int xbee_send_modify_at_command(char* command, char* value); |
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105 | |||
106 | /*Global Variables*/
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107 | |||
108 | #ifndef ROBOT
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109 | static char* xbee_com_port = XBEE_PORT_DEFAULT; |
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110 | static int xbee_stream; |
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111 | static pthread_t* xbee_listen_thread;
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112 | #endif
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113 | |||
114 | // TODO: is this a good size?
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115 | #define XBEE_BUFFER_SIZE 128 |
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116 | #define PACKET_BUFFER_SIZE 108 |
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117 | // a buffer for data received from the XBee
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118 | char arrival_buf[XBEE_BUFFER_SIZE];
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119 | // location of last unread byte in buffer
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120 | volatile int buffer_last = 0; |
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121 | // first unread byte in buffer
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122 | volatile int buffer_first = 0; |
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123 | |||
124 | |||
125 | //used to store packets as they are read
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126 | static char xbee_buf[PACKET_BUFFER_SIZE]; |
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127 | static int currentBufPos = 0; |
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128 | |||
129 | //XBee status
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130 | static unsigned int xbee_panID = XBEE_PAN_DEFAULT; |
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131 | static unsigned int xbee_pending_panID = XBEE_PAN_DEFAULT; |
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132 | static int xbee_channel = XBEE_CHANNEL_DEFAULT; |
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133 | static int xbee_pending_channel = XBEE_CHANNEL_DEFAULT; |
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134 | static volatile unsigned int xbee_address = 0; |
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135 | |||
136 | /*Function Implementations*/
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137 | |||
138 | #ifdef ROBOT
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139 | |||
140 | /**
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141 | * Interrupt for the robot. Adds bytes received from the xbee
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142 | * to the buffer.
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143 | **/
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144 | #ifndef FIREFLY
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145 | ISR(USART1_RX_vect) |
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146 | { |
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147 | char c = UDR1;
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148 | arrival_buf[buffer_last] = c; |
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149 | int t = buffer_last + 1; |
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150 | if (t == XBEE_BUFFER_SIZE)
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151 | t = 0;
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152 | if (t == buffer_first)
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153 | { |
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154 | WL_DEBUG_PRINT("\nOut of space in buffer.\n");
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155 | } |
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156 | buffer_last = t; |
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157 | } |
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158 | #else
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159 | SIGNAL(SIG_USART0_RECV) |
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160 | { |
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161 | char c = UDR0;
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162 | arrival_buf[buffer_last] = c; |
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163 | int t = buffer_last + 1; |
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164 | if (t == XBEE_BUFFER_SIZE)
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165 | t = 0;
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166 | if (t == buffer_first)
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167 | { |
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168 | WL_DEBUG_PRINT("Out of space in buffer.\n");
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169 | } |
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170 | buffer_last = t; |
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171 | } |
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172 | #endif
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173 | |||
174 | #else
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175 | |||
176 | // Computer code
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177 | |||
178 | /**
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179 | * Thread that listens to the xbee.
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180 | **/
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181 | static void* listen_to_xbee(void* x) |
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182 | { |
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183 | char c;
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184 | while (1) |
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185 | { |
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186 | if (xbee_read(&c, 1) != 0) { |
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187 | WL_DEBUG_PRINT("xbee_read failed.\n");
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188 | return NULL; |
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189 | } |
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190 | |||
191 | arrival_buf[buffer_last] = c; |
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192 | int t = buffer_last + 1; |
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193 | if (t == XBEE_BUFFER_SIZE)
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194 | t = 0;
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195 | if (t == buffer_first)
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196 | { |
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197 | WL_DEBUG_PRINT("Out of space in buffer.\n");
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198 | } |
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199 | buffer_last = t; |
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200 | |||
201 | usleep(1000);
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202 | } |
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203 | |||
204 | return NULL; |
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205 | } |
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206 | |||
207 | #endif
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208 | |||
209 | /**
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210 | * Initializes the XBee library so that other functions may be used.
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211 | **/
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212 | int xbee_lib_init()
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213 | { |
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214 | WL_DEBUG_PRINT("in xbee_init\n");
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215 | #ifdef ROBOT
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216 | |||
217 | //enable the receiving interrupt
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218 | #ifdef FIREFLY
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219 | UCSR0B |= _BV(RXCIE) | _BV(RXEN); |
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220 | #else
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221 | #ifdef BAYBOARD
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222 | UCSR1B |= _BV(RXCIE1); |
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223 | #else
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224 | UCSR1B |= _BV(RXCIE); |
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225 | #endif
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226 | #endif
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227 | sei(); |
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228 | #else
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229 | xbee_stream = open(xbee_com_port, O_RDWR); |
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230 | if (xbee_stream == -1/* || lockf(xbee_stream, F_TEST, 0) != 0*/) |
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231 | { |
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232 | WL_DEBUG_PRINT("Failed to open connection to XBee on port ");
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233 | WL_DEBUG_PRINT_INT(xbee_com_port); |
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234 | WL_DEBUG_PRINT(".\n");
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235 | return -1; |
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236 | } else {
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237 | WL_DEBUG_PRINT("Successfully opened connection to XBee on port ");
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238 | WL_DEBUG_PRINT_INT(xbee_com_port); |
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239 | WL_DEBUG_PRINT(".\n");
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240 | } |
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241 | |||
242 | // set baud rate, etc. correctly
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243 | struct termios options;
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244 | |||
245 | tcgetattr(xbee_stream, &options); |
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246 | cfsetispeed(&options, B9600); |
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247 | cfsetospeed(&options, B9600); |
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248 | options.c_iflag &= ~ICRNL; |
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249 | options.c_oflag &= ~OCRNL; |
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250 | options.c_cflag |= (CLOCAL | CREAD); |
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251 | options.c_cflag &= ~PARENB; |
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252 | options.c_cflag &= ~CSTOPB; |
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253 | options.c_cflag &= ~CSIZE; |
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254 | options.c_cflag |= CS8; |
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255 | options.c_lflag &= ~ICANON; |
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256 | options.c_cc[VMIN] = 1;
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257 | options.c_cc[VTIME] = 50;
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258 | |||
259 | if (tcsetattr(xbee_stream, TCSANOW, &options))
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260 | { |
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261 | WL_DEBUG_PRINT("Error setting attributes.\n");
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262 | return -1; |
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263 | } |
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264 | |||
265 | xbee_listen_thread = (pthread_t*)malloc(sizeof(pthread_t));
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266 | if (xbee_listen_thread == NULL) |
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267 | { |
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268 | WL_DEBUG_PRINT("Malloc failed.\n");
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269 | return -1; |
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270 | } |
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271 | |||
272 | int ret = pthread_create(xbee_listen_thread, NULL, listen_to_xbee, NULL); |
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273 | if (ret)
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274 | { |
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275 | WL_DEBUG_PRINT("Failed to create listener thread.\n");
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276 | return -1; |
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277 | } |
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278 | #endif
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279 | |||
280 | WL_DEBUG_PRINT("Entering command mode.\n");
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281 | |||
282 | if (xbee_enter_command_mode() != 0) { |
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283 | return -1; |
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284 | } |
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285 | |||
286 | WL_DEBUG_PRINT("Entered command mode.\n");
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287 | |||
288 | if (xbee_enter_api_mode() != 0) { |
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289 | return -1; |
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290 | } |
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291 | |||
292 | WL_DEBUG_PRINT("Entered api mode.\n");
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293 | |||
294 | if (xbee_exit_command_mode() != 0) { |
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295 | return -1; |
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296 | } |
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297 | |||
298 | WL_DEBUG_PRINT("Left command mode.\n");
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299 | |||
300 | if (xbee_send_read_at_command("MY")) { |
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301 | return -1; |
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302 | } |
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303 | WL_DEBUG_PRINT("Getting ATMY address.\n");
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304 | |||
305 | #ifndef ROBOT
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306 | int i;
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307 | for (i = 0; xbee_address == 0 && i < XBEE_GET_PACKET_TIMEOUT; i++) { |
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308 | ret = xbee_get_packet(NULL);
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309 | |||
310 | usleep(1000);
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311 | |||
312 | /* if (ret == -1) { */
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313 | /* WL_DEBUG_PRINT("xbee_get_packet(NULL) failed.\n"); */
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314 | /* return -1; */
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315 | /* } */
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316 | } |
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317 | #else
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318 | //wait to return until the address is set
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319 | //TODO: this shouldn't wait indefinitely. There should be some sort of reasonable timeout
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320 | // so if the address is never set right, an error can be returned instead of having the
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321 | // robot hang forever
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322 | while (xbee_address == 0) { |
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323 | xbee_get_packet(NULL);
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324 | } |
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325 | #endif
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326 | WL_DEBUG_PRINT("Got ATMY address.\n");
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327 | |||
328 | #ifndef ROBOT
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329 | if (i == XBEE_GET_PACKET_TIMEOUT) { // We timed-out. |
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330 | |||
331 | WL_DEBUG_PRINT("xbee_get_packet timed out.\n");
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332 | return -1; |
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333 | } else {
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334 | return 0; |
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335 | } |
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336 | #else
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337 | return 0; |
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338 | #endif
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339 | } |
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340 | |||
341 | /**
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342 | * Call when finished using the XBee library. This releases
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343 | * all sued resources.
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344 | **/
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345 | void xbee_terminate()
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346 | { |
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347 | #ifndef ROBOT
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348 | pthread_cancel(*xbee_listen_thread); |
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349 | pthread_join(*xbee_listen_thread, NULL);
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350 | free(xbee_listen_thread); |
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351 | lockf(xbee_stream, F_ULOCK, 0);
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352 | close(xbee_stream); |
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353 | 1437 | dsschult | #else
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354 | xbee_exit_api_mode(); |
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355 | 1432 | dsschult | #endif
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356 | } |
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357 | |||
358 | /**
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359 | * Send a buffer buf of size bytes to the XBee.
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360 | *
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361 | * @param buf the buffer of data to send
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362 | * @param size the number of bytes to send
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363 | **/
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364 | static int xbee_send(char* buf, int size) |
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365 | { |
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366 | #ifdef ROBOT
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367 | int i;
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368 | for (i = 0; i < size; i++) { |
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369 | xbee_putc(buf[i]); |
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370 | } |
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371 | |||
372 | return 0; |
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373 | |||
374 | #else
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375 | |||
376 | int ret = write(xbee_stream, buf, size);
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377 | //success
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378 | if (ret == size)
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379 | return 0; |
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380 | if (ret == -1) |
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381 | { |
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382 | //interrupted by system signal, probably timer interrupt.
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383 | //just try again
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384 | if (errno == 4) |
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385 | { |
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386 | return xbee_send(buf, size);
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387 | } |
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388 | WL_DEBUG_PRINT("Failed to write to xbee\r\n");
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389 | return -1; |
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390 | } |
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391 | |||
392 | //write was interrupted after writing ret bytes
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393 | return xbee_send(buf + ret, size - ret);
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394 | #endif
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395 | } |
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396 | |||
397 | /**
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398 | * Sends a string to the XBee.
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399 | *
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400 | * @param c the string to send to the XBEE
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401 | **/
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402 | static int xbee_send_string(char* c) |
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403 | { |
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404 | return xbee_send(c, strlen(c));
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405 | } |
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406 | |||
407 | #ifndef ROBOT
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408 | static int xbee_read(char* buf, int size) |
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409 | { |
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410 | if (read(xbee_stream, buf, size) == -1) { |
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411 | WL_DEBUG_PRINT("Failed to read from xbee.\r\n");
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412 | return -1; |
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413 | } |
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414 | |||
415 | return 0; |
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416 | } |
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417 | #endif
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418 | |||
419 | /**
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420 | * Enter into command mode.
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421 | **/
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422 | static int xbee_enter_command_mode() |
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423 | { |
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424 | if (xbee_send_string("+++") != 0) { |
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425 | return -1; |
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426 | } |
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427 | |||
428 | if (xbee_wait_for_ok() != 0) { |
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429 | return -1; |
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430 | } |
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431 | return 0; |
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432 | } |
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433 | |||
434 | /**
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435 | * Exit from command mode.
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436 | **/
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437 | static int xbee_exit_command_mode() |
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438 | { |
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439 | if (xbee_send_string("ATCN\r") != 0) { |
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440 | return -1; |
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441 | } |
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442 | |||
443 | xbee_wait_for_ok(); |
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444 | |||
445 | return 0; |
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446 | } |
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447 | |||
448 | /**
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449 | * Enter API mode.
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450 | **/
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451 | static int xbee_enter_api_mode() |
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452 | { |
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453 | if (xbee_send_string("ATAP 1\r") != 0) { |
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454 | return -1; |
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455 | } |
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456 | xbee_wait_for_ok(); |
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457 | |||
458 | return 0; |
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459 | } |
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460 | |||
461 | /**
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462 | 1437 | dsschult | * Exit API mode.
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463 | **/
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464 | static int xbee_exit_api_mode() |
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465 | { |
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466 | if (xbee_send_modify_at_command("AP","0") != 0) { |
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467 | return -1; |
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468 | } |
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469 | |||
470 | return 0; |
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471 | } |
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472 | |||
473 | /**
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474 | 1432 | dsschult | * Wait until the string "OK\r" is received from the XBee.
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475 | **/
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476 | static int xbee_wait_for_ok() |
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477 | { |
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478 | return xbee_wait_for_string("OK\r", 3); |
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479 | } |
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480 | |||
481 | /**
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482 | * Delay until the specified string is received from
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483 | * the XBee. Discards all other XBee data.
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484 | *
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485 | * ********* Robot often hangs here ****************
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486 | *
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487 | * @param s the string to receive
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488 | * @param len the length of the string
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489 | **/
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490 | static int xbee_wait_for_string(char* s, int len) |
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491 | { |
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492 | char* curr = s;
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493 | while (curr - s < len) {
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494 | WL_DEBUG_PRINT("waiting for string\r\n");
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495 | // check if buffer is empty
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496 | if (buffer_last != buffer_first) {
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497 | char c = arrival_buf[buffer_first++];
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498 | if (buffer_first == XBEE_BUFFER_SIZE) {
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499 | buffer_first = 0;
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500 | } |
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501 | |||
502 | if (c == *curr) {
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503 | curr++; |
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504 | } else {
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505 | #ifndef ROBOT
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506 | //return -1; // Computer is less forgiving.
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507 | curr = s; |
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508 | #else
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509 | curr = s; |
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510 | #endif
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511 | } |
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512 | } // else buffer is empty.
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513 | |||
514 | #ifndef ROBOT
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515 | usleep(100);
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516 | #endif
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517 | } |
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518 | |||
519 | return 0; |
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520 | } |
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521 | |||
522 | /**
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523 | * Verifies that the packets checksum is correct.
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524 | * (If the checksum is correct, the sum of the bytes
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525 | * is 0xFF.)
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526 | *
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527 | * @param packet the packet received. This includes the first
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528 | * three bytes, which are header information from the XBee.
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529 | *
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530 | * @param len The length of the packet received from the XBee
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531 | *
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532 | * @return 0 if the checksum is incorrect, nonzero
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533 | * otherwise
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534 | **/
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535 | int xbee_verify_checksum(char* packet, int len) |
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536 | { |
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537 | unsigned char sum = 0; |
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538 | int i;
|
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539 | for (i = 3; i < len; i++) |
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540 | sum += (unsigned char)packet[i]; |
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541 | return sum == 0xFF; |
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542 | } |
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543 | |||
544 | /**
|
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545 | * Returns the checksum of the given packet.
|
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546 | *
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547 |