root / trunk / code / projects / libwireless / lib / xbee.c @ 399
History | View | Annotate | Download (19.2 KB)
1 | 242 | bcoltin | /**
|
---|---|---|---|
2 | * Copyright (c) 2007 Colony Project
|
||
3 | *
|
||
4 | * Permission is hereby granted, free of charge, to any person
|
||
5 | * obtaining a copy of this software and associated documentation
|
||
6 | * files (the "Software"), to deal in the Software without
|
||
7 | * restriction, including without limitation the rights to use,
|
||
8 | * copy, modify, merge, publish, distribute, sublicense, and/or sell
|
||
9 | * copies of the Software, and to permit persons to whom the
|
||
10 | * Software is furnished to do so, subject to the following
|
||
11 | * conditions:
|
||
12 | *
|
||
13 | * The above copyright notice and this permission notice shall be
|
||
14 | * included in all copies or substantial portions of the Software.
|
||
15 | *
|
||
16 | * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
|
||
17 | * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES
|
||
18 | * OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
|
||
19 | * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT
|
||
20 | * HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
|
||
21 | * WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
|
||
22 | * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
|
||
23 | * OTHER DEALINGS IN THE SOFTWARE.
|
||
24 | **/
|
||
25 | |||
26 | /**
|
||
27 | * @file xbee.c
|
||
28 | * @brief XBee Interface
|
||
29 | *
|
||
30 | * Implementation of low level communication with the XBee in API mode.
|
||
31 | *
|
||
32 | * @author Brian Coltin, Colony Project, CMU Robotics Club
|
||
33 | **/
|
||
34 | |||
35 | 17 | bcoltin | #include "xbee.h" |
36 | #include "wl_defs.h" |
||
37 | |||
38 | #ifndef ROBOT
|
||
39 | |||
40 | #include <fcntl.h> |
||
41 | #include <unistd.h> |
||
42 | #include <pthread.h> |
||
43 | #include <errno.h> |
||
44 | 309 | emarinel | #include <termios.h> |
45 | 17 | bcoltin | |
46 | #else
|
||
47 | |||
48 | #include <serial.h> |
||
49 | #include <avr/interrupt.h> |
||
50 | |||
51 | #endif
|
||
52 | |||
53 | #include <stdio.h> |
||
54 | #include <stdlib.h> |
||
55 | #include <string.h> |
||
56 | |||
57 | #define XBEE_FRAME_START 0x7E |
||
58 | |||
59 | /*Frame Types*/
|
||
60 | #define XBEE_FRAME_STATUS 0x8A |
||
61 | #define XBEE_FRAME_AT_COMMAND 0x08 |
||
62 | #define XBEE_FRAME_AT_COMMAND_RESPONSE 0x88 |
||
63 | #define XBEE_FRAME_TX_REQUEST_64 0x00 |
||
64 | #define XBEE_FRAME_TX_REQUEST_16 0x01 |
||
65 | #define XBEE_FRAME_TX_STATUS XBEE_TX_STATUS
|
||
66 | #define XBEE_FRAME_RX_64 0x80 |
||
67 | #define XBEE_FRAME_RX_16 XBEE_RX
|
||
68 | |||
69 | /*Internal Function Prototypes*/
|
||
70 | |||
71 | /*I/O Functions*/
|
||
72 | 397 | emarinel | static int xbee_send(char* buf, int size); |
73 | static void xbee_send_string(char* c); |
||
74 | 17 | bcoltin | |
75 | #ifndef ROBOT
|
||
76 | void xbee_read(char* buf, int size); |
||
77 | #endif
|
||
78 | |||
79 | /*Command Mode Functions
|
||
80 | * Called during initialization.
|
||
81 | */
|
||
82 | void xbee_enter_command_mode(void); |
||
83 | void xbee_exit_command_mode(void); |
||
84 | void xbee_enter_api_mode(void); |
||
85 | 309 | emarinel | void xbee_exit_api_mode(void); |
86 | 17 | bcoltin | void xbee_wait_for_string(char* s, int len); |
87 | void xbee_wait_for_ok(void); |
||
88 | |||
89 | /*API Mode Functions*/
|
||
90 | |||
91 | int xbee_handle_packet(char* packet, int len); |
||
92 | 397 | emarinel | void xbee_handle_at_command_response(char* command, char result, char* extra, int extraLen); |
93 | 17 | bcoltin | void xbee_handle_status(char status); |
94 | int xbee_verify_checksum(char* packet, int len); |
||
95 | char xbee_compute_checksum(char* packet, int len); |
||
96 | void xbee_send_frame(char* buf, int len); |
||
97 | void xbee_send_read_at_command(char* command); |
||
98 | void xbee_send_modify_at_command(char* command, char* value); |
||
99 | |||
100 | /*Global Variables*/
|
||
101 | |||
102 | #ifndef ROBOT
|
||
103 | 399 | emarinel | static char* xbee_com_port = XBEE_PORT_DEFAULT; |
104 | static int xbee_stream; |
||
105 | static pthread_t* xbee_listen_thread;
|
||
106 | 17 | bcoltin | #endif
|
107 | |||
108 | 336 | bcoltin | // TODO: is this a good size?
|
109 | #define XBEE_BUFFER_SIZE 256 |
||
110 | // a buffer for data received from the XBee
|
||
111 | char arrival_buf[XBEE_BUFFER_SIZE];
|
||
112 | // location of last unread byte in buffer
|
||
113 | volatile int buffer_last = 0; |
||
114 | // first unread byte in buffer
|
||
115 | volatile int buffer_first = 0; |
||
116 | 17 | bcoltin | |
117 | 336 | bcoltin | |
118 | 17 | bcoltin | //used to store packets as they are read
|
119 | char xbee_buf[128]; |
||
120 | int currentBufPos = 0; |
||
121 | |||
122 | //XBee status
|
||
123 | unsigned int xbee_panID = XBEE_PAN_DEFAULT; |
||
124 | unsigned int xbee_pending_panID = XBEE_PAN_DEFAULT; |
||
125 | 60 | bcoltin | int xbee_channel = XBEE_CHANNEL_DEFAULT;
|
126 | int xbee_pending_channel = XBEE_CHANNEL_DEFAULT;
|
||
127 | 17 | bcoltin | unsigned int xbee_address = 0; |
128 | |||
129 | /*Function Implementations*/
|
||
130 | |||
131 | #ifdef ROBOT
|
||
132 | |||
133 | /**
|
||
134 | * Interrupt for the robot. Adds bytes received from the xbee
|
||
135 | 336 | bcoltin | * to the buffer.
|
136 | 17 | bcoltin | **/
|
137 | 86 | bcoltin | #ifndef FIREFLY
|
138 | 346 | bcoltin | ISR(USART1_RX_vect) |
139 | { |
||
140 | char c = UDR1;
|
||
141 | arrival_buf[buffer_last] = c; |
||
142 | int t = buffer_last + 1; |
||
143 | if (t == XBEE_BUFFER_SIZE)
|
||
144 | t = 0;
|
||
145 | if (t == buffer_first)
|
||
146 | { |
||
147 | WL_DEBUG_PRINT("Out of space in buffer.\n");
|
||
148 | } |
||
149 | buffer_last = t; |
||
150 | 17 | bcoltin | } |
151 | 86 | bcoltin | #else
|
152 | 346 | bcoltin | SIGNAL(SIG_USART0_RECV) |
153 | { |
||
154 | char c = UDR0;
|
||
155 | arrival_buf[buffer_last] = c; |
||
156 | int t = buffer_last + 1; |
||
157 | if (t == XBEE_BUFFER_SIZE)
|
||
158 | t = 0;
|
||
159 | if (t == buffer_first)
|
||
160 | { |
||
161 | WL_DEBUG_PRINT("Out of space in buffer.\n");
|
||
162 | } |
||
163 | buffer_last = t; |
||
164 | 86 | bcoltin | } |
165 | #endif
|
||
166 | 17 | bcoltin | |
167 | #else
|
||
168 | |||
169 | /**
|
||
170 | * Thread that listens to the xbee.
|
||
171 | **/
|
||
172 | 346 | bcoltin | void* listen_to_xbee(void* x) |
173 | { |
||
174 | char c;
|
||
175 | while (1) |
||
176 | { |
||
177 | xbee_read(&c, 1);
|
||
178 | arrival_buf[buffer_last] = c; |
||
179 | int t = buffer_last + 1; |
||
180 | if (t == XBEE_BUFFER_SIZE)
|
||
181 | t = 0;
|
||
182 | if (t == buffer_first)
|
||
183 | { |
||
184 | WL_DEBUG_PRINT("Out of space in buffer.\n");
|
||
185 | } |
||
186 | buffer_last = t; |
||
187 | } |
||
188 | return 0; |
||
189 | 17 | bcoltin | } |
190 | |||
191 | #endif
|
||
192 | |||
193 | /**
|
||
194 | * Initializes the XBee library so that other functions may be used.
|
||
195 | **/
|
||
196 | 399 | emarinel | int xbee_lib_init()
|
197 | 346 | bcoltin | { |
198 | arrival_buf[0] = 'A'; |
||
199 | arrival_buf[1] = 'A'; |
||
200 | arrival_buf[2] = 'A'; |
||
201 | #ifdef ROBOT
|
||
202 | 17 | bcoltin | |
203 | 346 | bcoltin | //enable the receiving interrupt
|
204 | #ifdef FIREFLY
|
||
205 | UCSR0B |= _BV(RXCIE) | _BV(RXEN); |
||
206 | #else
|
||
207 | UCSR1B |= _BV(RXCIE); |
||
208 | #endif
|
||
209 | sei(); |
||
210 | #else
|
||
211 | printf("Connecting to port %s.\n", xbee_com_port);
|
||
212 | xbee_stream = open(xbee_com_port, O_RDWR); |
||
213 | if (xbee_stream == -1/* || lockf(xbee_stream, F_TEST, 0) != 0*/) |
||
214 | { |
||
215 | printf("Failed to open connection to XBee on port %s\r\n", xbee_com_port);
|
||
216 | return -1; |
||
217 | } |
||
218 | 17 | bcoltin | |
219 | 346 | bcoltin | // set baud rate, etc. correctly
|
220 | struct termios options;
|
||
221 | 309 | emarinel | |
222 | 346 | bcoltin | tcgetattr(xbee_stream, &options); |
223 | cfsetispeed(&options, B9600); |
||
224 | cfsetospeed(&options, B9600); |
||
225 | options.c_iflag &= ~ICRNL; |
||
226 | options.c_oflag &= ~OCRNL; |
||
227 | options.c_cflag |= (CLOCAL | CREAD); |
||
228 | options.c_cflag &= ~PARENB; |
||
229 | options.c_cflag &= ~CSTOPB; |
||
230 | options.c_cflag &= ~CSIZE; |
||
231 | options.c_cflag |= CS8; |
||
232 | options.c_lflag &= ~ICANON; |
||
233 | options.c_cc[VMIN] = 1;
|
||
234 | options.c_cc[VTIME] = 50;
|
||
235 | 309 | emarinel | |
236 | 346 | bcoltin | if (tcsetattr(xbee_stream, TCSANOW, &options))
|
237 | { |
||
238 | fprintf(stderr, "Error setting attributes.\n");
|
||
239 | return -1; |
||
240 | } |
||
241 | 309 | emarinel | |
242 | 346 | bcoltin | //lockf(xbee_stream, F_LOCK, 0);
|
243 | 309 | emarinel | |
244 | 346 | bcoltin | xbee_listen_thread = |
245 | (pthread_t*)malloc(sizeof(pthread_t));
|
||
246 | if (xbee_listen_thread == NULL) |
||
247 | { |
||
248 | fprintf(stderr, "%s: Malloc failed.\n", __FUNCTION__);
|
||
249 | return -1; |
||
250 | } |
||
251 | 17 | bcoltin | |
252 | 346 | bcoltin | int ret = pthread_create(xbee_listen_thread, NULL, |
253 | listen_to_xbee, NULL);
|
||
254 | if (ret)
|
||
255 | { |
||
256 | fprintf(stderr, "Failed to create listener thread.\r\n");
|
||
257 | return -1; |
||
258 | } |
||
259 | 309 | emarinel | |
260 | 346 | bcoltin | #endif
|
261 | xbee_enter_command_mode(); |
||
262 | xbee_enter_api_mode(); |
||
263 | xbee_exit_command_mode(); |
||
264 | xbee_send_read_at_command("MY");
|
||
265 | 17 | bcoltin | |
266 | 346 | bcoltin | //wait to return until the address is set
|
267 | while (xbee_address == 0) xbee_get_packet(NULL); |
||
268 | 309 | emarinel | |
269 | 346 | bcoltin | |
270 | return 0; |
||
271 | 17 | bcoltin | } |
272 | |||
273 | /**
|
||
274 | * Call when finished using the XBee library. This releases
|
||
275 | * all sued resources.
|
||
276 | **/
|
||
277 | 346 | bcoltin | void xbee_terminate()
|
278 | { |
||
279 | #ifndef ROBOT
|
||
280 | pthread_cancel(*xbee_listen_thread); |
||
281 | free(xbee_listen_thread); |
||
282 | lockf(xbee_stream, F_ULOCK, 0);
|
||
283 | close(xbee_stream); |
||
284 | #endif
|
||
285 | 17 | bcoltin | } |
286 | |||
287 | /**
|
||
288 | * Send a buffer buf of size bytes to the XBee.
|
||
289 | *
|
||
290 | * @param buf the buffer of data to send
|
||
291 | * @param size the number of bytes to send
|
||
292 | **/
|
||
293 | 397 | emarinel | int xbee_send(char* buf, int size) |
294 | 346 | bcoltin | { |
295 | #ifdef ROBOT
|
||
296 | int i;
|
||
297 | for (i = 0; i < size; i++) |
||
298 | xbee_putc(buf[i]); |
||
299 | #else
|
||
300 | int ret = write(xbee_stream, buf, size);
|
||
301 | //success
|
||
302 | if (ret == size)
|
||
303 | 397 | emarinel | return 0; |
304 | 346 | bcoltin | if (ret == -1) |
305 | { |
||
306 | //interrupted by system signal, probably timer interrupt.
|
||
307 | //just try again
|
||
308 | if (errno == 4) |
||
309 | { |
||
310 | 397 | emarinel | return xbee_send(buf, size);
|
311 | 346 | bcoltin | } |
312 | printf("Failed to write to xbee, error %i.\r\n", errno);
|
||
313 | 397 | emarinel | return -1; |
314 | 346 | bcoltin | } |
315 | 17 | bcoltin | |
316 | 346 | bcoltin | //write was interrupted after writing ret bytes
|
317 | xbee_send(buf + ret, size - ret); |
||
318 | #endif
|
||
319 | 397 | emarinel | |
320 | return 0; |
||
321 | 17 | bcoltin | } |
322 | |||
323 | /**
|
||
324 | * Sends a string to the XBee.
|
||
325 | *
|
||
326 | * @param c the string to send to the XBEE
|
||
327 | **/
|
||
328 | 346 | bcoltin | void xbee_send_string(char* c) |
329 | { |
||
330 | xbee_send(c, strlen(c)); |
||
331 | 17 | bcoltin | } |
332 | |||
333 | #ifndef ROBOT
|
||
334 | 346 | bcoltin | void xbee_read(char* buf, int size) |
335 | { |
||
336 | if (read(xbee_stream, buf, size) == -1) |
||
337 | printf("Failed to read from xbee.\r\n");
|
||
338 | 17 | bcoltin | } |
339 | #endif
|
||
340 | |||
341 | /**
|
||
342 | * Enter into command mode.
|
||
343 | **/
|
||
344 | 346 | bcoltin | void xbee_enter_command_mode()
|
345 | { |
||
346 | xbee_send_string("+++");
|
||
347 | xbee_wait_for_ok(); |
||
348 | 17 | bcoltin | } |
349 | |||
350 | /**
|
||
351 | * Exit from command mode.
|
||
352 | **/
|
||
353 | 346 | bcoltin | void xbee_exit_command_mode()
|
354 | { |
||
355 | xbee_send_string("ATCN\r");
|
||
356 | xbee_wait_for_ok(); |
||
357 | 17 | bcoltin | } |
358 | |||
359 | /**
|
||
360 | * Enter API mode.
|
||
361 | **/
|
||
362 | 346 | bcoltin | void xbee_enter_api_mode()
|
363 | { |
||
364 | xbee_send_string("ATAP 1\r");
|
||
365 | xbee_wait_for_ok(); |
||
366 | 17 | bcoltin | } |
367 | |||
368 | /**
|
||
369 | 309 | emarinel | * Exit API mode. (warning - does not check for response)
|
370 | **/
|
||
371 | 346 | bcoltin | void xbee_exit_api_mode()
|
372 | { |
||
373 | xbee_send_string("ATAP 0\r");
|
||
374 | 309 | emarinel | } |
375 | |||
376 | /**
|
||
377 | 17 | bcoltin | * Wait until the string "OK\r" is received from the XBee.
|
378 | **/
|
||
379 | 346 | bcoltin | void xbee_wait_for_ok()
|
380 | { |
||
381 | xbee_wait_for_string("OK\r", 3); |
||
382 | 17 | bcoltin | } |
383 | |||
384 | /**
|
||
385 | * Delay until the specified string is received from
|
||
386 | * the XBee. Discards all other XBee data.
|
||
387 | *
|
||
388 | * @param s the string to receive
|
||
389 | * @param len the length of the string
|
||
390 | **/
|
||
391 | 346 | bcoltin | void xbee_wait_for_string(char* s, int len) |
392 | { |
||
393 | char* curr = s;
|
||
394 | while (curr - s < len)
|
||
395 | { |
||
396 | // check if buffer is empty
|
||
397 | if (buffer_last == buffer_first)
|
||
398 | continue;
|
||
399 | char c = arrival_buf[buffer_first++];
|
||
400 | if (buffer_first == XBEE_BUFFER_SIZE)
|
||
401 | buffer_first = 0;
|
||
402 | if (c == *curr)
|
||
403 | curr++; |
||
404 | else
|
||
405 | curr = s; |
||
406 | } |
||
407 | 17 | bcoltin | } |
408 | |||
409 | /**
|
||
410 | * Verifies that the packets checksum is correct.
|
||
411 | * (If the checksum is correct, the sum of the bytes
|
||
412 | * is 0xFF.)
|
||
413 | *
|
||
414 | * @param packet the packet received. This includes the first
|
||
415 | * three bytes, which are header information from the XBee.
|
||
416 | *
|
||
417 | * @param len The length of the packet received from the XBee
|
||
418 | *
|
||
419 | * @return 0 if the checksum is incorrect, nonzero
|
||
420 | * otherwise
|
||
421 | **/
|
||
422 | 346 | bcoltin | int xbee_verify_checksum(char* packet, int len) |
423 | { |
||
424 | unsigned char sum = 0; |
||
425 | int i;
|
||
426 | for (i = 3; i < len; i++) |
||
427 | sum += (unsigned char)packet[i]; |
||
428 | return sum == 0xFF; |
||
429 | 17 | bcoltin | } |
430 | |||
431 | /**
|
||
432 | * Returns the checksum of the given packet.
|
||
433 | *
|
||
434 | * @param buf the data for the packet to send
|
||
435 | * @param len the length of the packet in bytes
|
||
436 | *
|
||
437 | * @return the checksum of the packet, which will
|
||
438 | * become the last byte sent in the packet
|
||
439 | **/
|
||
440 | 346 | bcoltin | char xbee_compute_checksum(char* buf, int len) |
441 | { |
||
442 | int i;
|
||
443 | unsigned char sum = 0; |
||
444 | for (i = 0; i < len; i++) |
||
445 | sum += (unsigned char)buf[i]; |
||
446 | return 0xFF - sum; |
||
447 | 17 | bcoltin | } |
448 | |||
449 | /**
|
||
450 | * Adds header information and checksum to the given
|
||
451 | * packet and sends it. Header information includes
|
||
452 | * XBEE_FRAME_START and the packet length, as two bytes.
|
||
453 | *
|
||
454 | * @param buf the packet data
|
||
455 | * @param len the size in bytes of the packet data
|
||
456 | *
|
||
457 | **/
|
||
458 | 346 | bcoltin | void xbee_send_frame(char* buf, int len) |
459 | { |
||
460 | char prefix[3]; |
||
461 | prefix[0] = XBEE_FRAME_START;
|
||
462 | prefix[1] = (len & 0xFF00) >> 8; |
||
463 | prefix[2] = len & 0xFF; |
||
464 | char checksum = xbee_compute_checksum(buf, len);
|
||
465 | xbee_send(prefix, 3);
|
||
466 | xbee_send(buf, len); |
||
467 | xbee_send(&checksum, 1);
|
||
468 | 17 | bcoltin | } |
469 | |||
470 | /**
|
||
471 | * Sends an AT command to read a parameter.
|
||
472 | *
|
||
473 | * @param command the AT command to send. For exmaple,
|
||
474 | * use ID to read the PAN ID and MY to return the XBee ID.
|
||
475 | * See the XBee reference guide for a complete listing.
|
||
476 | **/
|
||
477 | 346 | bcoltin | void xbee_send_read_at_command(char* command) |
478 | { |
||
479 | xbee_send_modify_at_command(command, NULL);
|
||
480 | 17 | bcoltin | } |
481 | |||
482 | /**
|
||
483 | * Sends the given AT command.
|
||
484 | *
|
||
485 | * @param command the AT command to send (e.g., MY, ID)
|
||
486 | * @param value the value to pass as a parameter
|
||
487 | * (or NULL if there is no parameter)
|
||
488 | **/
|
||
489 | 346 | bcoltin | void xbee_send_modify_at_command(char* command, char* value) |
490 | { |
||
491 | char buf[16]; |
||
492 | int i;
|
||
493 | 17 | bcoltin | |
494 | 346 | bcoltin | buf[0] = XBEE_FRAME_AT_COMMAND;
|
495 | buf[1] = 1; |
||
496 | buf[2] = command[0]; |
||
497 | buf[3] = command[1]; |
||
498 | int valueLen = 0; |
||
499 | if (value != NULL) |
||
500 | { |
||
501 | valueLen = strlen(value); |
||
502 | if (valueLen > 8) |
||
503 | { |
||
504 | WL_DEBUG_PRINT("AT Command too large.\r\n");
|
||
505 | return;
|
||
506 | } |
||
507 | for (i = 0; i < valueLen; i++) |
||
508 | buf[4 + i] = value[i];
|
||
509 | } |
||
510 | xbee_send_frame(buf, 4 + valueLen);
|
||
511 | 17 | bcoltin | } |
512 | |||
513 | /**
|
||
514 | * Send the specified packet.
|
||
515 | *
|
||
516 | * @param packet the packet data to send
|
||
517 | * @param len the number of bytes in the packet
|
||
518 | *
|
||
519 | * @param dest the ID of the XBee to send the packet to,
|
||
520 | * or XBEE_BROADCAST to send the message to all robots
|
||
521 | * in the PAN.
|
||
522 | *
|
||
523 | * @param options a combination of the flags
|
||
524 | * XBEE_OPTIONS_NONE, XBEE_OPTIONS_DISABLE_RESPONSE and
|
||
525 | * XBEE_OPTIONS_BROADCAST_ALL_PANS
|
||
526 | *
|
||
527 | * @param frame the frame number to associate this packet
|
||
528 | * with. This will be used to identify the response when
|
||
529 | * the XBee alerts us as to whether or not our message
|
||
530 | * was received.
|
||
531 | **/
|
||
532 | 397 | emarinel | int xbee_send_packet(char* packet, int len, int dest, char options, char frame) |
533 | 346 | bcoltin | { |
534 | char buf[5]; |
||
535 | char prefix[3]; |
||
536 | int i;
|
||
537 | unsigned char checksum = 0; |
||
538 | 17 | bcoltin | |
539 | 346 | bcoltin | if (len > 100) |
540 | { |
||
541 | WL_DEBUG_PRINT("Packet is too large.\r\n");
|
||
542 | 397 | emarinel | return -1; |
543 | 346 | bcoltin | } |
544 | 17 | bcoltin | |
545 | 346 | bcoltin | //data for sending request
|
546 | buf[0] = XBEE_FRAME_TX_REQUEST_16;
|
||
547 | buf[1] = frame;
|
||
548 | buf[2] = (dest >> 8) & 0xFF; |
||
549 | buf[3] = dest & 0xFF; |
||
550 | buf[4] = options;
|
||
551 | 17 | bcoltin | |
552 | 346 | bcoltin | //packet prefix, do this here so we don't need an extra buffer
|
553 | prefix[0] = XBEE_FRAME_START;
|
||
554 | prefix[1] = ((5 + len) & 0xFF00) >> 8; |
||
555 | prefix[2] = (5 + len) & 0xFF; |
||
556 | 17 | bcoltin | |
557 | 346 | bcoltin | for (i = 0; i < 5; i++) |
558 | checksum += (unsigned char)buf[i]; |
||
559 | for (i = 0; i < len; i++) |
||
560 | checksum += (unsigned char)packet[i]; |
||
561 | checksum = 0xFF - checksum;
|
||
562 | 397 | emarinel | |
563 | if (xbee_send(prefix, 3) != 0) { |
||
564 | return -1; |
||
565 | } |
||
566 | |||
567 | if (xbee_send(buf, 5) != 0) { |
||
568 | return -1; |
||
569 | } |
||
570 | |||
571 | if (xbee_send(packet, len) != 0) { |
||
572 | return -1; |
||
573 | } |
||
574 | |||
575 | if (xbee_send((char*)&checksum, 1) != 0) { |
||
576 | return -1; |
||
577 | } |
||
578 | |||
579 | return 0; |
||
580 | 17 | bcoltin | } |
581 | |||
582 | /**
|
||
583 | * Reads a packet received from the XBee. This function
|
||
584 | * is non-blocking. The resulting packet is stored in dest.
|
||
585 | * Only returns transmission response packets and
|
||
586 | * received packets. The returned packet does not include
|
||
587 | * header information or the checksum. This method also
|
||
588 | * handles special packets dealt with by the XBee library,
|
||
589 | * and so should be called frequently while the XBee is in
|
||
590 | * use.<br><br>
|
||
591 | *
|
||
592 | * The first byte of the packet will be either
|
||
593 | * XBEE_TX_STATUS or XBEE_RX to indicated
|
||
594 | * a response to a sent message or a received message,
|
||
595 | * respectively.<br><br>
|
||
596 | *
|
||
597 | * For a status response packet:<br>
|
||
598 | * The first byte will be XBEE_TX_STATUS.<br>
|
||
599 | * The second byte will be the frame number.<br>
|
||
600 | * The third byte will be the result. 0 indicates success,
|
||
601 | * and nonzero indicates that an error ocurred in
|
||
602 | * transmitting the packet.<br><br>
|
||
603 | *
|
||
604 | * For a received packet:<br>
|
||
605 | * The first byte will be XBEE_RX.<br>
|
||
606 | * The second and third bytes will be the 16-bit
|
||
607 | * address of the packet's sender.<br>
|
||
608 | * The fourth byte is the signal strength.<br>
|
||
609 | * The fifth byte is 1 if the packet were sent to
|
||
610 | * a specific address, and 2 if it is a broadcast packet.<br><br>
|
||
611 | *
|
||
612 | * @param dest set to the packet data
|
||
613 | * @return the length of the packet, or -1 if no packet
|
||
614 | * is available
|
||
615 | **/
|
||
616 | 346 | bcoltin | int xbee_get_packet(unsigned char* dest) |
617 | { |
||
618 | //start reading a packet with XBEE_FRAME_START
|
||
619 | if (currentBufPos == 0) |
||
620 | { |
||
621 | do
|
||
622 | { |
||
623 | if (buffer_first == XBEE_BUFFER_SIZE)
|
||
624 | buffer_first = 0;
|
||
625 | // check if buffer is empty
|
||
626 | if (buffer_first == buffer_last)
|
||
627 | return -1; |
||
628 | } |
||
629 | while (arrival_buf[buffer_first++] != XBEE_FRAME_START);
|
||
630 | if (buffer_first == XBEE_BUFFER_SIZE)
|
||
631 | buffer_first = 0;
|
||
632 | xbee_buf[0] = XBEE_FRAME_START;
|
||
633 | currentBufPos++; |
||
634 | } |
||
635 | 17 | bcoltin | |
636 | 346 | bcoltin | int len = -1; |
637 | if (currentBufPos >= 3) |
||
638 | len = (int)xbee_buf[2] + ((int)xbee_buf[1] << 8); |
||
639 | 17 | bcoltin | |
640 | 346 | bcoltin | while (len == -1 //packet length has not been read yet |
641 | || currentBufPos < len + 4)
|
||
642 | { |
||
643 | if (currentBufPos == 3) |
||
644 | { |
||
645 | len = (int)xbee_buf[2] + ((int)xbee_buf[1] << 8); |
||
646 | if (len > 120) |
||
647 | { |
||
648 | WL_DEBUG_PRINT("Packet too large. Probably error in XBee transmission.\n");
|
||
649 | currentBufPos = 0;
|
||
650 | return -1; |
||
651 | } |
||
652 | } |
||
653 | // check if buffer is empty
|
||
654 | if (buffer_first == buffer_last)
|
||
655 | return -1; |
||
656 | xbee_buf[currentBufPos++] = arrival_buf[buffer_first++]; |
||
657 | if (buffer_first == XBEE_BUFFER_SIZE)
|
||
658 | buffer_first = 0;
|
||
659 | } |
||
660 | |||
661 | 17 | bcoltin | currentBufPos = 0;
|
662 | |||
663 | 346 | bcoltin | if (!xbee_verify_checksum(xbee_buf, len + 4)) |
664 | { |
||
665 | WL_DEBUG_PRINT("XBee checksum failed.\r\n");
|
||
666 | return -1; |
||
667 | } |
||
668 | 17 | bcoltin | |
669 | 346 | bcoltin | //we will take care of the packet
|
670 | if (xbee_handle_packet(xbee_buf + 3, len)) |
||
671 | return -1; |
||
672 | 17 | bcoltin | |
673 | 346 | bcoltin | if (dest == NULL) |
674 | return -1; |
||
675 | 17 | bcoltin | |
676 | 346 | bcoltin | int i;
|
677 | for (i = 3; i < len + 3; i++) |
||
678 | dest[i - 3] = xbee_buf[i];
|
||
679 | return len;
|
||
680 | 17 | bcoltin | } |
681 | |||
682 | /**
|
||
683 | * Handles modem status packets.
|
||
684 | *
|
||
685 | * @param status the type of status packet received.
|
||
686 | **/
|
||
687 | 346 | bcoltin | void xbee_handle_status(char status) |
688 | { |
||
689 | switch (status)
|
||
690 | { |
||
691 | case 0: |
||
692 | WL_DEBUG_PRINT("XBee hardware reset.\r\n");
|
||
693 | break;
|
||
694 | case 1: |
||
695 | WL_DEBUG_PRINT("Watchdog timer reset.\r\n");
|
||
696 | break;
|
||
697 | case 2: |
||
698 | WL_DEBUG_PRINT("Associated.\r\n");
|
||
699 | break;
|
||
700 | case 3: |
||
701 | WL_DEBUG_PRINT("Disassociated.\r\n");
|
||
702 | break;
|
||
703 | case 4: |
||
704 | WL_DEBUG_PRINT("Synchronization lost.\r\n");
|
||
705 | break;
|
||
706 | case 5: |
||
707 | WL_DEBUG_PRINT("Coordinator realignment.\r\n");
|
||
708 | break;
|
||
709 | case 6: |
||
710 | WL_DEBUG_PRINT("Coordinator started.\r\n");
|
||
711 | break;
|
||
712 | } |
||
713 | 17 | bcoltin | } |
714 | |||
715 | /**
|
||
716 | * Handles AT command response packets.
|
||
717 | * @param command the two character AT command, e.g. MY or ID
|
||
718 | * @param result 0 for success, 1 for an error
|
||
719 | * @param extra the hex value of the requested register
|
||
720 | * @param extraLen the length in bytes of extra
|
||
721 | **/
|
||
722 | void xbee_handle_at_command_response(char* command, char result, |
||
723 | 346 | bcoltin | char* extra, int extraLen) |
724 | { |
||
725 | if (result == 1) |
||
726 | { |
||
727 | WL_DEBUG_PRINT("Error with AT");
|
||
728 | WL_DEBUG_PRINT(command); |
||
729 | WL_DEBUG_PRINT(" packet.\r\n");
|
||
730 | } |
||
731 | WL_DEBUG_PRINT("AT");
|
||
732 | WL_DEBUG_PRINT(command); |
||
733 | WL_DEBUG_PRINT(" command was successful.\r\n");
|
||
734 | 17 | bcoltin | |
735 | 346 | bcoltin | if (command[0] == 'I' && command[1] == 'D') |
736 | { |
||
737 | xbee_panID = xbee_pending_panID; |
||
738 | WL_DEBUG_PRINT("PAN ID set to ");
|
||
739 | WL_DEBUG_PRINT_INT(xbee_panID); |
||
740 | WL_DEBUG_PRINT(".\r\n");
|
||
741 | return;
|
||
742 | } |
||
743 | 60 | bcoltin | |
744 | 346 | bcoltin | if (command[0] == 'C' && command[1] == 'H') |
745 | { |
||
746 | xbee_channel = xbee_pending_channel; |
||
747 | WL_DEBUG_PRINT("Channel set to ");
|
||
748 | WL_DEBUG_PRINT_INT(xbee_channel); |
||
749 | WL_DEBUG_PRINT(".\r\n");
|
||
750 | return;
|
||
751 | } |
||
752 | 17 | bcoltin | |
753 | 346 | bcoltin | if (command[0] == 'M' && command[1] == 'Y' && extraLen != 0) |
754 | { |
||
755 | xbee_address = 0;
|
||
756 | int i;
|
||
757 | for (i = 0; i < extraLen; i++) |
||
758 | xbee_address = (xbee_address << 8) + extra[i];
|
||
759 | 17 | bcoltin | |
760 | 346 | bcoltin | WL_DEBUG_PRINT("XBee address is ");
|
761 | WL_DEBUG_PRINT_INT(xbee_address); |
||
762 | WL_DEBUG_PRINT(".\r\n");
|
||
763 | 17 | bcoltin | |
764 | 346 | bcoltin | if (xbee_address == 0) |
765 | { |
||
766 | WL_DEBUG_PRINT("XBee 16-bit address must be set using ATMY.\r\n");
|
||
767 | exit(0);
|
||
768 | } |
||
769 | } |
||
770 | 17 | bcoltin | } |
771 | |||
772 | /**
|
||
773 | * Attempts to handle the packet if it is dealt with
|
||
774 | * by the library.
|
||
775 | * We will handle the following packet types:
|
||
776 | * Modem Status
|
||
777 | * AT Command Response
|
||
778 | *
|
||
779 | * @param packet the packet to handle
|
||
780 | * @param len the length of the packet
|
||
781 | *
|
||
782 | * @return 1 if we have handled the packet, 0 otherwise
|
||
783 | */
|
||
784 | 346 | bcoltin | int xbee_handle_packet(char* packet, int len) |
785 | { |
||
786 | char command[3] = {1, 2, 3}; |
||
787 | if (len <= 0) //this should not happend |
||
788 | { |
||
789 | WL_DEBUG_PRINT("Non-positive packet length.\r\n");
|
||
790 | return 0; |
||
791 | } |
||
792 | 17 | bcoltin | |
793 | 346 | bcoltin | switch ((unsigned char)packet[0]) //packet type |
794 | { |
||
795 | case XBEE_FRAME_STATUS:
|
||
796 | xbee_handle_status(packet[1]);
|
||
797 | return 1; |
||
798 | case XBEE_FRAME_AT_COMMAND_RESPONSE:
|
||
799 | command[0] = packet[2]; |
||
800 | command[1] = packet[3]; |
||
801 | command[2] = 0; |
||
802 | xbee_handle_at_command_response(command, |
||
803 | packet[4], packet + 5, len - 5); |
||
804 | return 1; |
||
805 | } |
||
806 | return 0; |
||
807 | 17 | bcoltin | } |
808 | |||
809 | /**
|
||
810 | * Sets the personal area network id.
|
||
811 | *
|
||
812 | * @param id the new personal area network (PAN) id
|
||
813 | **/
|
||
814 | 346 | bcoltin | void xbee_set_pan_id(int id) |
815 | { |
||
816 | char s[3]; |
||
817 | s[0] = (id >> 8) & 0xFF; |
||
818 | s[1] = id & 0xFF; |
||
819 | s[2] = 0; |
||
820 | xbee_pending_panID = id; |
||
821 | xbee_send_modify_at_command("ID", s);
|
||
822 | 17 | bcoltin | } |
823 | |||
824 | /**
|
||
825 | * Get the PAN ID for the XBee.
|
||
826 | *
|
||
827 | * @return the personal area network id, or
|
||
828 | * XBEE_PAN_DEFAULT if it has not yet been set.
|
||
829 | **/
|
||
830 | 346 | bcoltin | unsigned int xbee_get_pan_id() |
831 | { |
||
832 | return xbee_panID;
|
||
833 | 17 | bcoltin | } |
834 | |||
835 | /**
|
||
836 | 60 | bcoltin | * Set the channel the XBee is using.
|
837 | *
|
||
838 | * @param channel the channel the XBee will not use,
|
||
839 | * between 0x0B and 0x1A
|
||
840 | *
|
||
841 | * @see xbee_get_channel
|
||
842 | **/
|
||
843 | 346 | bcoltin | void xbee_set_channel(int channel) |
844 | { |
||
845 | if (channel < 0x0B || channel > 0x1A) |
||
846 | { |
||
847 | WL_DEBUG_PRINT("Channel out of range.\r\n");
|
||
848 | return;
|
||
849 | } |
||
850 | char s[3]; |
||
851 | s[0] = channel & 0xFF; |
||
852 | s[1] = 0; |
||
853 | xbee_pending_channel = channel; |
||
854 | xbee_send_modify_at_command("CH", s);
|
||
855 | 60 | bcoltin | } |
856 | |||
857 | /**
|
||
858 | * Returns the channel which the XBee is currently using.
|
||
859 | *
|
||
860 | * @return the channel the XBee is using
|
||
861 | *
|
||
862 | * @see xbee_set_channel
|
||
863 | **/
|
||
864 | 346 | bcoltin | int xbee_get_channel(void) |
865 | { |
||
866 | return xbee_channel;
|
||
867 | 60 | bcoltin | } |
868 | |||
869 | /**
|
||
870 | 17 | bcoltin | * Get the 16-bit address of the XBee.
|
871 | * This is used to specify who to send messages to
|
||
872 | * and who messages are from.
|
||
873 | *
|
||
874 | * @return the 16-bit address of the XBee.
|
||
875 | **/
|
||
876 | 346 | bcoltin | unsigned int xbee_get_address() |
877 | { |
||
878 | return xbee_address;
|
||
879 | 17 | bcoltin | } |
880 | |||
881 | 203 | justin | #ifndef ROBOT
|
882 | 346 | bcoltin | void xbee_set_com_port(char* port) |
883 | { |
||
884 | xbee_com_port = port; |
||
885 | 203 | justin | } |
886 | #endif
|