Project

General

Profile

Statistics
| Revision:

root / branches / slam / code / lib / src / libwireless / wireless.c @ 111

History | View | Annotate | Download (9.36 KB)

1
#include "wireless.h"
2
#include "xbee.h"
3
#include <stdlib.h>
4
#include <stdio.h>
5

    
6
#include "wl_defs.h"
7

    
8
#ifndef ROBOT
9
#include <sys/time.h>
10
#include <signal.h>
11
#else
12
#include <time.h>
13
#ifndef FIREFLY
14
#include <bom.h>
15
#endif
16
#endif
17

    
18
/*Function Prototypes*/
19

    
20
void wl_do_timeout(void);
21

    
22
//Note: the actual frame sent has group as the first four bits and
23
//frame as the last four.
24
void wl_send_packet(char group, char type, char* data, int len,
25
                                        int dest, char options, char frame);
26

    
27
/*Data Members*/
28

    
29
//used to store incoming and outgoing packets
30
unsigned char wl_buf[128];
31
//1 if we have timed out since we last checked, 0 otherwise.
32
int wl_timeout = 0;
33

    
34
PacketGroupHandler* wl_packet_groups[WL_MAX_PACKET_GROUPS];
35

    
36
#ifndef ROBOT
37
#ifdef _POSIX_TIMERS
38
timer_t wl_timeout_timer;
39
#endif
40
//called when we time out, or receive interrupt
41
void sig_handler(int signo)
42
{
43
        switch (signo)
44
        {
45
                case SIGALRM:
46
                        wl_timeout = 1;
47
                        break;
48
                case SIGINT:
49
                        wl_terminate();
50
                        exit(1);
51
                        break;
52
        }
53
        return;
54
}
55
#else 
56
//Alternate non posix code here.
57

    
58
#endif
59

    
60
/**
61
 * Initializes the wireless library. Must be called before any
62
 * other function.
63
 **/
64
void wl_init()
65
{
66
        int i;
67
        for (i = 0; i < WL_MAX_PACKET_GROUPS; i++)
68
                wl_packet_groups[i] = NULL;
69

    
70
        xbee_lib_init();
71
        
72
        //begin timeout timer
73
        #ifdef ROBOT
74
        #ifdef FIREFLY
75
        rtc_init(PRESCALE_DIV_128, 32, &wl_do_timeout);
76
        #else
77
        rtc_init(HALF_SECOND, &wl_do_timeout); 
78
        #endif
79
        #else
80
        
81
  #ifdef _POSIX_TIMERS 
82
  
83
  //create a timer to trigger every half second
84
        struct sigevent evp;
85
        evp.sigev_signo = SIGALRM;
86
        evp.sigev_notify = SIGEV_SIGNAL;
87
        if (timer_create(CLOCK_REALTIME, &evp, &wl_timeout_timer) == -1)
88
        { 
89
                WL_DEBUG_PRINT("Error creating a timer.\r\n"); 
90
                exit(1); 
91
        }
92
        
93
  struct itimerspec wl_timeout_time;
94
        wl_timeout_time.it_interval.tv_sec = 0;
95
        wl_timeout_time.it_interval.tv_nsec = 500000000;
96
        wl_timeout_time.it_value.tv_sec = 0;
97
        wl_timeout_time.it_value.tv_nsec = 500000000;
98
        timer_settime(wl_timeout_timer, 0,
99
                        &wl_timeout_time, NULL);
100
  #else
101
  
102
  printf("Creating a non posix timer.\n"); 
103
  struct itimerval timer_val;
104
  struct timeval interval;
105
  interval.tv_sec = 0;
106
  interval.tv_usec = 500000;
107
  struct timeval first_time;
108
  first_time.tv_sec = 0;
109
  first_time.tv_usec = 500000;
110
  timer_val.it_interval = interval;
111
  timer_val.it_value = first_time;
112
  if(setitimer(ITIMER_REAL,&timer_val,NULL)==-1)
113
  {
114
                WL_DEBUG_PRINT("Error creating a timer.\r\n"); 
115
    perror("Failure's cause");
116
                exit(1); 
117
  }
118
  
119
  #endif
120

    
121
        struct sigaction wl_sig_act;
122
        wl_sig_act.sa_handler = (void *)sig_handler;
123
        wl_sig_act.sa_flags = 0;
124
        sigemptyset(&wl_sig_act.sa_mask);
125
        sigaction(SIGALRM, &wl_sig_act, 0);
126
        sigaction(SIGINT, &wl_sig_act, 0);
127
        #endif
128
}
129

    
130
/**
131
 * Uninitializes the wireless library.
132
 **/
133
void wl_terminate()
134
{
135
        #ifndef ROBOT
136
  #ifdef _POSIX_TIMERS        
137
  timer_delete(wl_timeout_timer);
138
  #endif
139
        #endif
140
        
141
        int i;
142
        for (i = 0; i < WL_MAX_PACKET_GROUPS; i++)
143
                if (wl_packet_groups[i] != NULL &&
144
                        wl_packet_groups[i]->unregister != NULL)
145
                        wl_packet_groups[i]->unregister();
146
        
147
        xbee_terminate();
148
}
149

    
150
/**
151
 * Set the PAN for the XBee to join.
152
 *
153
 * @param pan the new PAN
154
 *
155
 * @see wl_get_pan
156
 **/
157
void wl_set_pan(int pan)
158
{
159
        xbee_set_pan_id(pan);
160
}
161

    
162
/**
163
 * Get the PAN the XBee is currently part of.
164
 *
165
 * @return the PAN of the XBee
166
 *
167
 * @see wl_set_pan
168
 **/
169
int wl_get_pan(void)
170
{
171
        return xbee_get_pan_id();
172
}
173

    
174
/**
175
 * Set the channel the XBee is listening to.
176
 *
177
 * @param channel the new channel to join
178
 *
179
 * @see wl_get_channel
180
 **/
181
void wl_set_channel(int channel)
182
{
183
        xbee_set_channel(channel);
184
}
185

    
186
/**
187
 * Get the channel the XBee is part of.
188
 *
189
 * @return the channel the XBee is part of
190
 *
191
 * @see wl_set_channel
192
 **/
193
int wl_get_channel(void)
194
{
195
        return xbee_get_channel();
196
}
197

    
198
/**
199
 * Returns the 16-bit address of the XBee module.
200
 *
201
 * @return the 16-bit address of the XBee module.
202
 **/
203
unsigned int wl_get_xbee_id()
204
{
205
        return xbee_get_address();
206
}
207

    
208
/**
209
 * Send a packet to a specific XBee without specifying a PAN.
210
 *
211
 * @param group the packet group
212
 * @param type the packet type
213
 * @param data the packet data
214
 * @param len the packet length in bytes
215
 * @param dest the 16-bit address of the XBee to send the packet to
216
 * @param frame the frame number to see with a TX_STATUS response
217
 **/
218
void wl_send_robot_to_robot_global_packet(char group, char type,
219
                char* data, int len, int dest, char frame)
220
{
221
        wl_send_packet(group, type, data, len, dest,
222
                        XBEE_OPTIONS_BROADCAST_ALL_PANS, frame);
223
}
224

    
225
/**
226
 * Send a packet to a specific XBee in the same PAN.
227
 *
228
 * @param group the packet group
229
 * @param type the packet type
230
 * @param data the packet data
231
 * @param len the packet length in bytes
232
 * @param dest the 16-bit address of the XBee to send the packet to
233
 * @param frame the frame number to see with a TX_STATUS response
234
 **/
235
void wl_send_robot_to_robot_packet(char group, char type,
236
                char* data, int len, int dest, char frame)
237
{
238
        wl_send_packet(group, type, data, len, dest, XBEE_OPTIONS_NONE,
239
                        frame);
240
}
241

    
242
/**
243
 * Send a packet to all XBees in all PANs.
244
 *
245
 * @param group the packet group
246
 * @param type the packet type
247
 * @param data the packet data
248
 * @param len the packet length in bytes
249
 * @param frame the frame number to see with a TX_STATUS response
250
 **/
251
void wl_send_global_packet(char group, char type,
252
                char* data, int len, char frame)
253
{
254
        wl_send_packet(group, type, data, len, XBEE_BROADCAST,
255
                        XBEE_OPTIONS_BROADCAST_ALL_PANS, frame);
256
}
257

    
258
/**
259
 * Send a packet to all XBee's in the same PAN.
260
 *
261
 * @param group the packet group
262
 * @param type the packet type
263
 * @param data the packet data
264
 * @param len the packet length in bytes
265
 * @param frame the frame number to see with a TX_STATUS response
266
 **/
267
void wl_send_pan_packet(char group, char type,
268
                char* data, int len, char frame)
269
{
270
        wl_send_packet(group, type, data, len, XBEE_BROADCAST, 
271
                        XBEE_OPTIONS_NONE, frame);
272
}
273

    
274
/**
275
 * Send a packet.
276
 *
277
 * @param group the packet group
278
 * @param type the packet type
279
 * @param data the packet data
280
 * @param len the packet length in bytes
281
 * @param dest the destination of the packet
282
 * @param options the options for sending the packet
283
 * @param frame the frame number to see with a TX_STATUS response
284
 **/
285
void wl_send_packet(char group, char type, char* data, int len,
286
                                        int dest, char options, char frame)
287
{
288
        char buf[128];
289
        int i;
290
        if (frame != 0)
291
                frame = (frame & 0x0F) | ((group & 0x0F) << 4);
292
        buf[0] = group;
293
        buf[1] = type;
294
        for (i = 0; i < len; i++)
295
                buf[2 + i] = data[i];
296
        xbee_send_packet(buf, len + 2, dest, options, frame);
297
}
298

    
299
/**
300
 * Register a packet group with the wireless library. The event
301
 * handlers in the packet group will be called whenever an
302
 * event dealing with the packet group's group code occurs.
303
 *
304
 * @param h the PacketGroupHandler to register
305
 **/
306
void wl_register_packet_group(PacketGroupHandler* h)
307
{
308
        if (h->groupCode >= WL_MAX_PACKET_GROUPS)
309
        {
310
                WL_DEBUG_PRINT("Packet group code too large.\r\n");
311
                return;
312
        }
313
        if (wl_packet_groups[h->groupCode] != NULL)
314
        {
315
                WL_DEBUG_PRINT("Packet group code already registered.\r\n");
316
                return;
317
        }
318
        wl_packet_groups[h->groupCode] = h;
319
}
320

    
321
/**
322
 * Unregister a packet group from the wireless library.
323
 * 
324
 * @param h the packet group to remove
325
 **/
326
void wl_unregister_packet_group(PacketGroupHandler* h)
327
{
328
        unsigned int groupCode = h->groupCode;
329
        PacketGroupHandler* p = wl_packet_groups[groupCode];
330
        if (p != NULL && p->unregister != NULL)
331
                p->unregister();
332
        wl_packet_groups[groupCode] = NULL;
333
}
334

    
335
/**
336
 * Called when the timer is triggered. This calls the timeout
337
 * handlers of all the registered packet groups.
338
 **/
339
void wl_do_timeout()
340
{
341
        int i;
342
        for (i = 0; i < WL_MAX_PACKET_GROUPS; i++)
343
                if (wl_packet_groups[i] != NULL &&
344
                        wl_packet_groups[i]->timeout_handler != NULL)
345
                        wl_packet_groups[i]->timeout_handler();
346
}
347

    
348
/**
349
 * Performs wireless library functionality. This function must
350
 * be called frequently for wireless to perform effectively.
351
 * This function will call timeout handlers, as well as
352
 * received packet and transmit status handlers.
353
 **/
354
void wl_do()
355
{
356
        if (wl_timeout)
357
        {
358
                wl_do_timeout();
359
                wl_timeout = 0;
360
        }
361
        
362
        int len = xbee_get_packet(wl_buf);
363
        if (len < 0)//no packet received
364
                return;
365
        
366
        if (wl_buf[0] == XBEE_TX_STATUS)
367
        {
368
                if (len != 3)
369
                {
370
                        WL_DEBUG_PRINT("Transmit Status packet should be of length 3.\r\n");
371
                        return;
372
                }
373
                
374
                //the first four bits are the packet group
375
                //this only works with under 16 groups
376
                int group = (int)(wl_buf[1] >> 4);
377
                int success = 0;
378
                if (wl_buf[2] == 0)
379
                        success = 1;
380
                else
381
                {
382
                        WL_DEBUG_PRINT("No response received.\r\n");
383
                        if (wl_buf[2] == 2)
384
                                WL_DEBUG_PRINT("CCA Failure\r\n");
385
                        if (wl_buf[2] == 3)
386
                                WL_DEBUG_PRINT("Purged\r\n");
387
                }
388
                
389
                if (wl_packet_groups[group] != NULL &&
390
                                        wl_packet_groups[group]->handle_response != NULL)
391
                        wl_packet_groups[group]->handle_response(
392
                                        (int)wl_buf[1] & 0x0F, success);
393
                return;
394
        }
395
        
396
        if (wl_buf[0] == XBEE_RX)
397
        {
398
                if (len < 7)
399
                {
400
                        WL_DEBUG_PRINT("Packet is too small.\r\n");
401
                        return;
402
                }
403
                
404
                int source = ((int)wl_buf[1] << 8) + ((int)wl_buf[2]);
405
                
406
                /*
407
                //unused for now
408
                int signalStrength = wl_buf[3];
409
                //1 for Address broadcast, 2 for PAN broadcast
410
                int options = wl_buf[4];
411
                */
412
                
413
                int group = wl_buf[5];
414
                int type = wl_buf[6];
415
                int packetLen = len - 7;
416
                
417
                if (wl_packet_groups[group] != NULL
418
                                && wl_packet_groups[group]->handle_receive != NULL)
419
                        wl_packet_groups[group]->handle_receive(type, source, 
420
                                wl_buf + 7, packetLen);
421
                return;
422
        }
423
        
424
        WL_DEBUG_PRINT("Unexpected packet received from XBee.\r\n");
425
        return;
426
}
427