summaryrefslogtreecommitdiff
path: root/lib/usbhost/USB_Host_Shield_2.0/SPP.cpp
blob: 8169707661f2f200c348e14c58ec39888ce3deca (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
/* Copyright (C) 2012 Kristian Lauszus, TKJ Electronics. All rights reserved.

 This software may be distributed and modified under the terms of the GNU
 General Public License version 2 (GPL2) as published by the Free Software
 Foundation and appearing in the file GPL2.TXT included in the packaging of
 this file. Please note that GPL2 Section 2[b] requires that all works based
 on this software must also be made publicly available under the terms of
 the GPL2 ("Copyleft").

 Contact information
 -------------------

 Kristian Lauszus, TKJ Electronics
 Web      :  http://www.tkjelectronics.com
 e-mail   :  kristianl@tkjelectronics.com
 */

#include "SPP.h"
// To enable serial debugging see "settings.h"
//#define EXTRADEBUG // Uncomment to get even more debugging data
//#define PRINTREPORT // Uncomment to print the report sent to the Arduino

/*
 * CRC (reversed crc) lookup table as calculated by the table generator in ETSI TS 101 369 V6.3.0.
 */
const uint8_t rfcomm_crc_table[256] PROGMEM = {/* reversed, 8-bit, poly=0x07 */
        0x00, 0x91, 0xE3, 0x72, 0x07, 0x96, 0xE4, 0x75, 0x0E, 0x9F, 0xED, 0x7C, 0x09, 0x98, 0xEA, 0x7B,
        0x1C, 0x8D, 0xFF, 0x6E, 0x1B, 0x8A, 0xF8, 0x69, 0x12, 0x83, 0xF1, 0x60, 0x15, 0x84, 0xF6, 0x67,
        0x38, 0xA9, 0xDB, 0x4A, 0x3F, 0xAE, 0xDC, 0x4D, 0x36, 0xA7, 0xD5, 0x44, 0x31, 0xA0, 0xD2, 0x43,
        0x24, 0xB5, 0xC7, 0x56, 0x23, 0xB2, 0xC0, 0x51, 0x2A, 0xBB, 0xC9, 0x58, 0x2D, 0xBC, 0xCE, 0x5F,
        0x70, 0xE1, 0x93, 0x02, 0x77, 0xE6, 0x94, 0x05, 0x7E, 0xEF, 0x9D, 0x0C, 0x79, 0xE8, 0x9A, 0x0B,
        0x6C, 0xFD, 0x8F, 0x1E, 0x6B, 0xFA, 0x88, 0x19, 0x62, 0xF3, 0x81, 0x10, 0x65, 0xF4, 0x86, 0x17,
        0x48, 0xD9, 0xAB, 0x3A, 0x4F, 0xDE, 0xAC, 0x3D, 0x46, 0xD7, 0xA5, 0x34, 0x41, 0xD0, 0xA2, 0x33,
        0x54, 0xC5, 0xB7, 0x26, 0x53, 0xC2, 0xB0, 0x21, 0x5A, 0xCB, 0xB9, 0x28, 0x5D, 0xCC, 0xBE, 0x2F,
        0xE0, 0x71, 0x03, 0x92, 0xE7, 0x76, 0x04, 0x95, 0xEE, 0x7F, 0x0D, 0x9C, 0xE9, 0x78, 0x0A, 0x9B,
        0xFC, 0x6D, 0x1F, 0x8E, 0xFB, 0x6A, 0x18, 0x89, 0xF2, 0x63, 0x11, 0x80, 0xF5, 0x64, 0x16, 0x87,
        0xD8, 0x49, 0x3B, 0xAA, 0xDF, 0x4E, 0x3C, 0xAD, 0xD6, 0x47, 0x35, 0xA4, 0xD1, 0x40, 0x32, 0xA3,
        0xC4, 0x55, 0x27, 0xB6, 0xC3, 0x52, 0x20, 0xB1, 0xCA, 0x5B, 0x29, 0xB8, 0xCD, 0x5C, 0x2E, 0xBF,
        0x90, 0x01, 0x73, 0xE2, 0x97, 0x06, 0x74, 0xE5, 0x9E, 0x0F, 0x7D, 0xEC, 0x99, 0x08, 0x7A, 0xEB,
        0x8C, 0x1D, 0x6F, 0xFE, 0x8B, 0x1A, 0x68, 0xF9, 0x82, 0x13, 0x61, 0xF0, 0x85, 0x14, 0x66, 0xF7,
        0xA8, 0x39, 0x4B, 0xDA, 0xAF, 0x3E, 0x4C, 0xDD, 0xA6, 0x37, 0x45, 0xD4, 0xA1, 0x30, 0x42, 0xD3,
        0xB4, 0x25, 0x57, 0xC6, 0xB3, 0x22, 0x50, 0xC1, 0xBA, 0x2B, 0x59, 0xC8, 0xBD, 0x2C, 0x5E, 0xCF
};

SPP::SPP(BTD *p, const char* name, const char* pin) :
BluetoothService(p) // Pointer to BTD class instance - mandatory
{
        pBtd->btdName = name;
        pBtd->btdPin = pin;

        /* Set device cid for the SDP and RFCOMM channelse */
        sdp_dcid[0] = 0x50; // 0x0050
        sdp_dcid[1] = 0x00;
        rfcomm_dcid[0] = 0x51; // 0x0051
        rfcomm_dcid[1] = 0x00;

        Reset();
}

void SPP::Reset() {
        connected = false;
        RFCOMMConnected = false;
        SDPConnected = false;
        waitForLastCommand = false;
        l2cap_sdp_state = L2CAP_SDP_WAIT;
        l2cap_rfcomm_state = L2CAP_RFCOMM_WAIT;
        l2cap_event_flag = 0;
        sppIndex = 0;
        creditSent = false;
}

void SPP::disconnect() {
        connected = false;
        // First the two L2CAP channels has to be disconnected and then the HCI connection
        if(RFCOMMConnected)
                pBtd->l2cap_disconnection_request(hci_handle, ++identifier, rfcomm_scid, rfcomm_dcid);
        if(RFCOMMConnected && SDPConnected)
                delay(1); // Add delay between commands
        if(SDPConnected)
                pBtd->l2cap_disconnection_request(hci_handle, ++identifier, sdp_scid, sdp_dcid);
        l2cap_sdp_state = L2CAP_DISCONNECT_RESPONSE;
}

void SPP::ACLData(uint8_t* l2capinbuf) {
        if(!connected) {
                if(l2capinbuf[8] == L2CAP_CMD_CONNECTION_REQUEST) {
                        if((l2capinbuf[12] | (l2capinbuf[13] << 8)) == SDP_PSM && !pBtd->sdpConnectionClaimed) {
                                pBtd->sdpConnectionClaimed = true;
                                hci_handle = pBtd->hci_handle; // Store the HCI Handle for the connection
                                l2cap_sdp_state = L2CAP_SDP_WAIT; // Reset state
                        } else if((l2capinbuf[12] | (l2capinbuf[13] << 8)) == RFCOMM_PSM && !pBtd->rfcommConnectionClaimed) {
                                pBtd->rfcommConnectionClaimed = true;
                                hci_handle = pBtd->hci_handle; // Store the HCI Handle for the connection
                                l2cap_rfcomm_state = L2CAP_RFCOMM_WAIT; // Reset state
                        }
                }
        }

        if(checkHciHandle(l2capinbuf, hci_handle)) { // acl_handle_ok
                if((l2capinbuf[6] | (l2capinbuf[7] << 8)) == 0x0001U) { // l2cap_control - Channel ID for ACL-U
                        if(l2capinbuf[8] == L2CAP_CMD_COMMAND_REJECT) {
#ifdef DEBUG_USB_HOST
                                Notify(PSTR("\r\nL2CAP Command Rejected - Reason: "), 0x80);
                                D_PrintHex<uint8_t > (l2capinbuf[13], 0x80);
                                Notify(PSTR(" "), 0x80);
                                D_PrintHex<uint8_t > (l2capinbuf[12], 0x80);
                                Notify(PSTR(" Data: "), 0x80);
                                D_PrintHex<uint8_t > (l2capinbuf[17], 0x80);
                                Notify(PSTR(" "), 0x80);
                                D_PrintHex<uint8_t > (l2capinbuf[16], 0x80);
                                Notify(PSTR(" "), 0x80);
                                D_PrintHex<uint8_t > (l2capinbuf[15], 0x80);
                                Notify(PSTR(" "), 0x80);
                                D_PrintHex<uint8_t > (l2capinbuf[14], 0x80);
#endif
                        } else if(l2capinbuf[8] == L2CAP_CMD_CONNECTION_REQUEST) {
#ifdef EXTRADEBUG
                                Notify(PSTR("\r\nL2CAP Connection Request - PSM: "), 0x80);
                                D_PrintHex<uint8_t > (l2capinbuf[13], 0x80);
                                Notify(PSTR(" "), 0x80);
                                D_PrintHex<uint8_t > (l2capinbuf[12], 0x80);
                                Notify(PSTR(" SCID: "), 0x80);
                                D_PrintHex<uint8_t > (l2capinbuf[15], 0x80);
                                Notify(PSTR(" "), 0x80);
                                D_PrintHex<uint8_t > (l2capinbuf[14], 0x80);
                                Notify(PSTR(" Identifier: "), 0x80);
                                D_PrintHex<uint8_t > (l2capinbuf[9], 0x80);
#endif
                                if((l2capinbuf[12] | (l2capinbuf[13] << 8)) == SDP_PSM) { // It doesn't matter if it receives another reqeust, since it waits for the channel to disconnect in the L2CAP_SDP_DONE state, and the l2cap_event_flag will be cleared if so
                                        identifier = l2capinbuf[9];
                                        sdp_scid[0] = l2capinbuf[14];
                                        sdp_scid[1] = l2capinbuf[15];
                                        l2cap_set_flag(L2CAP_FLAG_CONNECTION_SDP_REQUEST);
                                } else if((l2capinbuf[12] | (l2capinbuf[13] << 8)) == RFCOMM_PSM) { // ----- || -----
                                        identifier = l2capinbuf[9];
                                        rfcomm_scid[0] = l2capinbuf[14];
                                        rfcomm_scid[1] = l2capinbuf[15];
                                        l2cap_set_flag(L2CAP_FLAG_CONNECTION_RFCOMM_REQUEST);
                                }
                        } else if(l2capinbuf[8] == L2CAP_CMD_CONFIG_RESPONSE) {
                                if((l2capinbuf[16] | (l2capinbuf[17] << 8)) == 0x0000) { // Success
                                        if(l2capinbuf[12] == sdp_dcid[0] && l2capinbuf[13] == sdp_dcid[1]) {
                                                //Notify(PSTR("\r\nSDP Configuration Complete"), 0x80);
                                                l2cap_set_flag(L2CAP_FLAG_CONFIG_SDP_SUCCESS);
                                        } else if(l2capinbuf[12] == rfcomm_dcid[0] && l2capinbuf[13] == rfcomm_dcid[1]) {
                                                //Notify(PSTR("\r\nRFCOMM Configuration Complete"), 0x80);
                                                l2cap_set_flag(L2CAP_FLAG_CONFIG_RFCOMM_SUCCESS);
                                        }
                                }
                        } else if(l2capinbuf[8] == L2CAP_CMD_CONFIG_REQUEST) {
                                if(l2capinbuf[12] == sdp_dcid[0] && l2capinbuf[13] == sdp_dcid[1]) {
                                        //Notify(PSTR("\r\nSDP Configuration Request"), 0x80);
                                        pBtd->l2cap_config_response(hci_handle, l2capinbuf[9], sdp_scid);
                                } else if(l2capinbuf[12] == rfcomm_dcid[0] && l2capinbuf[13] == rfcomm_dcid[1]) {
                                        //Notify(PSTR("\r\nRFCOMM Configuration Request"), 0x80);
                                        pBtd->l2cap_config_response(hci_handle, l2capinbuf[9], rfcomm_scid);
                                }
                        } else if(l2capinbuf[8] == L2CAP_CMD_DISCONNECT_REQUEST) {
                                if(l2capinbuf[12] == sdp_dcid[0] && l2capinbuf[13] == sdp_dcid[1]) {
                                        //Notify(PSTR("\r\nDisconnect Request: SDP Channel"), 0x80);
                                        identifier = l2capinbuf[9];
                                        l2cap_set_flag(L2CAP_FLAG_DISCONNECT_SDP_REQUEST);
                                } else if(l2capinbuf[12] == rfcomm_dcid[0] && l2capinbuf[13] == rfcomm_dcid[1]) {
                                        //Notify(PSTR("\r\nDisconnect Request: RFCOMM Channel"), 0x80);
                                        identifier = l2capinbuf[9];
                                        l2cap_set_flag(L2CAP_FLAG_DISCONNECT_RFCOMM_REQUEST);
                                }
                        } else if(l2capinbuf[8] == L2CAP_CMD_DISCONNECT_RESPONSE) {
                                if(l2capinbuf[12] == sdp_scid[0] && l2capinbuf[13] == sdp_scid[1]) {
                                        //Notify(PSTR("\r\nDisconnect Response: SDP Channel"), 0x80);
                                        identifier = l2capinbuf[9];
                                        l2cap_set_flag(L2CAP_FLAG_DISCONNECT_RESPONSE);
                                } else if(l2capinbuf[12] == rfcomm_scid[0] && l2capinbuf[13] == rfcomm_scid[1]) {
                                        //Notify(PSTR("\r\nDisconnect Response: RFCOMM Channel"), 0x80);
                                        identifier = l2capinbuf[9];
                                        l2cap_set_flag(L2CAP_FLAG_DISCONNECT_RESPONSE);
                                }
                        } else if(l2capinbuf[8] == L2CAP_CMD_INFORMATION_REQUEST) {
#ifdef DEBUG_USB_HOST
                                Notify(PSTR("\r\nInformation request"), 0x80);
#endif
                                identifier = l2capinbuf[9];
                                pBtd->l2cap_information_response(hci_handle, identifier, l2capinbuf[12], l2capinbuf[13]);
                        }
#ifdef EXTRADEBUG
                        else {
                                Notify(PSTR("\r\nL2CAP Unknown Signaling Command: "), 0x80);
                                D_PrintHex<uint8_t > (l2capinbuf[8], 0x80);
                        }
#endif
                } else if(l2capinbuf[6] == sdp_dcid[0] && l2capinbuf[7] == sdp_dcid[1]) { // SDP
                        if(l2capinbuf[8] == SDP_SERVICE_SEARCH_ATTRIBUTE_REQUEST_PDU) {
                                if(((l2capinbuf[16] << 8 | l2capinbuf[17]) == SERIALPORT_UUID) || ((l2capinbuf[16] << 8 | l2capinbuf[17]) == 0x0000 && (l2capinbuf[18] << 8 | l2capinbuf[19]) == SERIALPORT_UUID)) { // Check if it's sending the full UUID, see: https://www.bluetooth.org/Technical/AssignedNumbers/service_discovery.htm, we will just check the first four bytes
                                        if(firstMessage) {
                                                serialPortResponse1(l2capinbuf[9], l2capinbuf[10]);
                                                firstMessage = false;
                                        } else {
                                                serialPortResponse2(l2capinbuf[9], l2capinbuf[10]); // Serialport continuation state
                                                firstMessage = true;
                                        }
                                } else if(((l2capinbuf[16] << 8 | l2capinbuf[17]) == L2CAP_UUID) || ((l2capinbuf[16] << 8 | l2capinbuf[17]) == 0x0000 && (l2capinbuf[18] << 8 | l2capinbuf[19]) == L2CAP_UUID)) {
                                        if(firstMessage) {
                                                l2capResponse1(l2capinbuf[9], l2capinbuf[10]);
                                                firstMessage = false;
                                        } else {
                                                l2capResponse2(l2capinbuf[9], l2capinbuf[10]); // L2CAP continuation state
                                                firstMessage = true;
                                        }
                                } else
                                        serviceNotSupported(l2capinbuf[9], l2capinbuf[10]); // The service is not supported
#ifdef EXTRADEBUG
                                Notify(PSTR("\r\nUUID: "), 0x80);
                                uint16_t uuid;
                                if((l2capinbuf[16] << 8 | l2capinbuf[17]) == 0x0000) // Check if it's sending the UUID as a 128-bit UUID
                                        uuid = (l2capinbuf[18] << 8 | l2capinbuf[19]);
                                else // Short UUID
                                        uuid = (l2capinbuf[16] << 8 | l2capinbuf[17]);
                                D_PrintHex<uint16_t > (uuid, 0x80);

                                Notify(PSTR("\r\nLength: "), 0x80);
                                uint16_t length = l2capinbuf[11] << 8 | l2capinbuf[12];
                                D_PrintHex<uint16_t > (length, 0x80);
                                Notify(PSTR("\r\nData: "), 0x80);
                                for(uint8_t i = 0; i < length; i++) {
                                        D_PrintHex<uint8_t > (l2capinbuf[13 + i], 0x80);
                                        Notify(PSTR(" "), 0x80);
                                }
#endif
                        }
#ifdef EXTRADEBUG
                        else {
                                Notify(PSTR("\r\nUnknown PDU: "), 0x80);
                                D_PrintHex<uint8_t > (l2capinbuf[8], 0x80);
                        }
#endif
                } else if(l2capinbuf[6] == rfcomm_dcid[0] && l2capinbuf[7] == rfcomm_dcid[1]) { // RFCOMM
                        rfcommChannel = l2capinbuf[8] & 0xF8;
                        rfcommDirection = l2capinbuf[8] & 0x04;
                        rfcommCommandResponse = l2capinbuf[8] & 0x02;
                        rfcommChannelType = l2capinbuf[9] & 0xEF;
                        rfcommPfBit = l2capinbuf[9] & 0x10;

                        if(rfcommChannel >> 3 != 0x00)
                                rfcommChannelConnection = rfcommChannel;

#ifdef EXTRADEBUG
                        Notify(PSTR("\r\nRFCOMM Channel: "), 0x80);
                        D_PrintHex<uint8_t > (rfcommChannel >> 3, 0x80);
                        Notify(PSTR(" Direction: "), 0x80);
                        D_PrintHex<uint8_t > (rfcommDirection >> 2, 0x80);
                        Notify(PSTR(" CommandResponse: "), 0x80);
                        D_PrintHex<uint8_t > (rfcommCommandResponse >> 1, 0x80);
                        Notify(PSTR(" ChannelType: "), 0x80);
                        D_PrintHex<uint8_t > (rfcommChannelType, 0x80);
                        Notify(PSTR(" PF_BIT: "), 0x80);
                        D_PrintHex<uint8_t > (rfcommPfBit, 0x80);
#endif
                        if(rfcommChannelType == RFCOMM_DISC) {
#ifdef DEBUG_USB_HOST
                                Notify(PSTR("\r\nReceived Disconnect RFCOMM Command on channel: "), 0x80);
                                D_PrintHex<uint8_t > (rfcommChannel >> 3, 0x80);
#endif
                                connected = false;
                                sendRfcomm(rfcommChannel, rfcommDirection, rfcommCommandResponse, RFCOMM_UA, rfcommPfBit, rfcommbuf, 0x00); // UA Command
                        }
                        if(connected) {
                                /* Read the incoming message */
                                if(rfcommChannelType == RFCOMM_UIH && rfcommChannel == rfcommChannelConnection) {
                                        uint8_t length = l2capinbuf[10] >> 1; // Get length
                                        uint8_t offset = l2capinbuf[4] - length - 4; // Check if there is credit
                                        if(checkFcs(&l2capinbuf[8], l2capinbuf[11 + length + offset])) {
                                                uint8_t i = 0;
                                                for(; i < length; i++) {
                                                        if(rfcommAvailable + i >= sizeof (rfcommDataBuffer)) {
#ifdef DEBUG_USB_HOST
                                                                Notify(PSTR("\r\nWarning: Buffer is full!"), 0x80);
#endif
                                                                break;
                                                        }
                                                        rfcommDataBuffer[rfcommAvailable + i] = l2capinbuf[11 + i + offset];
                                                }
                                                rfcommAvailable += i;
#ifdef EXTRADEBUG
                                                Notify(PSTR("\r\nRFCOMM Data Available: "), 0x80);
                                                Notify(rfcommAvailable, 0x80);
                                                if(offset) {
                                                        Notify(PSTR(" - Credit: 0x"), 0x80);
                                                        D_PrintHex<uint8_t > (l2capinbuf[11], 0x80);
                                                }
#endif
                                        }
#ifdef DEBUG_USB_HOST
                                        else
                                                Notify(PSTR("\r\nError in FCS checksum!"), 0x80);
#endif
#ifdef PRINTREPORT // Uncomment "#define PRINTREPORT" to print the report send to the Arduino via Bluetooth
                                        for(uint8_t i = 0; i < length; i++)
                                                Notifyc(l2capinbuf[i + 11 + offset], 0x80);
#endif
                                } else if(rfcommChannelType == RFCOMM_UIH && l2capinbuf[11] == BT_RFCOMM_RPN_CMD) { // UIH Remote Port Negotiation Command
#ifdef DEBUG_USB_HOST
                                        Notify(PSTR("\r\nReceived UIH Remote Port Negotiation Command"), 0x80);
#endif
                                        rfcommbuf[0] = BT_RFCOMM_RPN_RSP; // Command
                                        rfcommbuf[1] = l2capinbuf[12]; // Length and shiftet like so: length << 1 | 1
                                        rfcommbuf[2] = l2capinbuf[13]; // Channel: channel << 1 | 1
                                        rfcommbuf[3] = l2capinbuf[14]; // Pre difined for Bluetooth, see 5.5.3 of TS 07.10 Adaption for RFCOMM
                                        rfcommbuf[4] = l2capinbuf[15]; // Priority
                                        rfcommbuf[5] = l2capinbuf[16]; // Timer
                                        rfcommbuf[6] = l2capinbuf[17]; // Max Fram Size LSB
                                        rfcommbuf[7] = l2capinbuf[18]; // Max Fram Size MSB
                                        rfcommbuf[8] = l2capinbuf[19]; // MaxRatransm.
                                        rfcommbuf[9] = l2capinbuf[20]; // Number of Frames
                                        sendRfcomm(rfcommChannel, rfcommDirection, 0, RFCOMM_UIH, rfcommPfBit, rfcommbuf, 0x0A); // UIH Remote Port Negotiation Response
                                } else if(rfcommChannelType == RFCOMM_UIH && l2capinbuf[11] == BT_RFCOMM_MSC_CMD) { // UIH Modem Status Command
#ifdef DEBUG_USB_HOST
                                        Notify(PSTR("\r\nSend UIH Modem Status Response"), 0x80);
#endif
                                        rfcommbuf[0] = BT_RFCOMM_MSC_RSP; // UIH Modem Status Response
                                        rfcommbuf[1] = 2 << 1 | 1; // Length and shiftet like so: length << 1 | 1
                                        rfcommbuf[2] = l2capinbuf[13]; // Channel: (1 << 0) | (1 << 1) | (0 << 2) | (channel << 3)
                                        rfcommbuf[3] = l2capinbuf[14];
                                        sendRfcomm(rfcommChannel, rfcommDirection, 0, RFCOMM_UIH, rfcommPfBit, rfcommbuf, 0x04);
                                }
                        } else {
                                if(rfcommChannelType == RFCOMM_SABM) { // SABM Command - this is sent twice: once for channel 0 and then for the channel to establish
#ifdef DEBUG_USB_HOST
                                        Notify(PSTR("\r\nReceived SABM Command"), 0x80);
#endif
                                        sendRfcomm(rfcommChannel, rfcommDirection, rfcommCommandResponse, RFCOMM_UA, rfcommPfBit, rfcommbuf, 0x00); // UA Command
                                } else if(rfcommChannelType == RFCOMM_UIH && l2capinbuf[11] == BT_RFCOMM_PN_CMD) { // UIH Parameter Negotiation Command
#ifdef DEBUG_USB_HOST
                                        Notify(PSTR("\r\nReceived UIH Parameter Negotiation Command"), 0x80);
#endif
                                        rfcommbuf[0] = BT_RFCOMM_PN_RSP; // UIH Parameter Negotiation Response
                                        rfcommbuf[1] = l2capinbuf[12]; // Length and shiftet like so: length << 1 | 1
                                        rfcommbuf[2] = l2capinbuf[13]; // Channel: channel << 1 | 1
                                        rfcommbuf[3] = 0xE0; // Pre difined for Bluetooth, see 5.5.3 of TS 07.10 Adaption for RFCOMM
                                        rfcommbuf[4] = 0x00; // Priority
                                        rfcommbuf[5] = 0x00; // Timer
                                        rfcommbuf[6] = BULK_MAXPKTSIZE - 14; // Max Fram Size LSB - set to the size of received data (50)
                                        rfcommbuf[7] = 0x00; // Max Fram Size MSB
                                        rfcommbuf[8] = 0x00; // MaxRatransm.
                                        rfcommbuf[9] = 0x00; // Number of Frames
                                        sendRfcomm(rfcommChannel, rfcommDirection, 0, RFCOMM_UIH, rfcommPfBit, rfcommbuf, 0x0A);
                                } else if(rfcommChannelType == RFCOMM_UIH && l2capinbuf[11] == BT_RFCOMM_MSC_CMD) { // UIH Modem Status Command
#ifdef DEBUG_USB_HOST
                                        Notify(PSTR("\r\nSend UIH Modem Status Response"), 0x80);
#endif
                                        rfcommbuf[0] = BT_RFCOMM_MSC_RSP; // UIH Modem Status Response
                                        rfcommbuf[1] = 2 << 1 | 1; // Length and shiftet like so: length << 1 | 1
                                        rfcommbuf[2] = l2capinbuf[13]; // Channel: (1 << 0) | (1 << 1) | (0 << 2) | (channel << 3)
                                        rfcommbuf[3] = l2capinbuf[14];
                                        sendRfcomm(rfcommChannel, rfcommDirection, 0, RFCOMM_UIH, rfcommPfBit, rfcommbuf, 0x04);

                                        delay(1);
#ifdef DEBUG_USB_HOST
                                        Notify(PSTR("\r\nSend UIH Modem Status Command"), 0x80);
#endif
                                        rfcommbuf[0] = BT_RFCOMM_MSC_CMD; // UIH Modem Status Command
                                        rfcommbuf[1] = 2 << 1 | 1; // Length and shiftet like so: length << 1 | 1
                                        rfcommbuf[2] = l2capinbuf[13]; // Channel: (1 << 0) | (1 << 1) | (0 << 2) | (channel << 3)
                                        rfcommbuf[3] = 0x8D; // Can receive frames (YES), Ready to Communicate (YES), Ready to Receive (YES), Incomig Call (NO), Data is Value (YES)

                                        sendRfcomm(rfcommChannel, rfcommDirection, 0, RFCOMM_UIH, rfcommPfBit, rfcommbuf, 0x04);
                                } else if(rfcommChannelType == RFCOMM_UIH && l2capinbuf[11] == BT_RFCOMM_MSC_RSP) { // UIH Modem Status Response
                                        if(!creditSent) {
#ifdef DEBUG_USB_HOST
                                                Notify(PSTR("\r\nSend UIH Command with credit"), 0x80);
#endif
                                                sendRfcommCredit(rfcommChannelConnection, rfcommDirection, 0, RFCOMM_UIH, 0x10, sizeof (rfcommDataBuffer)); // Send credit
                                                creditSent = true;
                                                timer = millis();
                                                waitForLastCommand = true;
                                        }
                                } else if(rfcommChannelType == RFCOMM_UIH && l2capinbuf[10] == 0x01) { // UIH Command with credit
#ifdef DEBUG_USB_HOST
                                        Notify(PSTR("\r\nReceived UIH Command with credit"), 0x80);
#endif
                                } else if(rfcommChannelType == RFCOMM_UIH && l2capinbuf[11] == BT_RFCOMM_RPN_CMD) { // UIH Remote Port Negotiation Command
#ifdef DEBUG_USB_HOST
                                        Notify(PSTR("\r\nReceived UIH Remote Port Negotiation Command"), 0x80);
#endif
                                        rfcommbuf[0] = BT_RFCOMM_RPN_RSP; // Command
                                        rfcommbuf[1] = l2capinbuf[12]; // Length and shiftet like so: length << 1 | 1
                                        rfcommbuf[2] = l2capinbuf[13]; // Channel: channel << 1 | 1
                                        rfcommbuf[3] = l2capinbuf[14]; // Pre difined for Bluetooth, see 5.5.3 of TS 07.10 Adaption for RFCOMM
                                        rfcommbuf[4] = l2capinbuf[15]; // Priority
                                        rfcommbuf[5] = l2capinbuf[16]; // Timer
                                        rfcommbuf[6] = l2capinbuf[17]; // Max Fram Size LSB
                                        rfcommbuf[7] = l2capinbuf[18]; // Max Fram Size MSB
                                        rfcommbuf[8] = l2capinbuf[19]; // MaxRatransm.
                                        rfcommbuf[9] = l2capinbuf[20]; // Number of Frames
                                        sendRfcomm(rfcommChannel, rfcommDirection, 0, RFCOMM_UIH, rfcommPfBit, rfcommbuf, 0x0A); // UIH Remote Port Negotiation Response
#ifdef DEBUG_USB_HOST
                                        Notify(PSTR("\r\nRFCOMM Connection is now established\r\n"), 0x80);
#endif
                                        onInit();
                                }
#ifdef EXTRADEBUG
                                else if(rfcommChannelType != RFCOMM_DISC) {
                                        Notify(PSTR("\r\nUnsupported RFCOMM Data - ChannelType: "), 0x80);
                                        D_PrintHex<uint8_t > (rfcommChannelType, 0x80);
                                        Notify(PSTR(" Command: "), 0x80);
                                        D_PrintHex<uint8_t > (l2capinbuf[11], 0x80);
                                }
#endif
                        }
                }
#ifdef EXTRADEBUG
                else {
                        Notify(PSTR("\r\nUnsupported L2CAP Data - Channel ID: "), 0x80);
                        D_PrintHex<uint8_t > (l2capinbuf[7], 0x80);
                        Notify(PSTR(" "), 0x80);
                        D_PrintHex<uint8_t > (l2capinbuf[6], 0x80);
                }
#endif
                SDP_task();
                RFCOMM_task();
        }
}

void SPP::Run() {
        if(waitForLastCommand && (millis() - timer) > 100) { // We will only wait 100ms and see if the UIH Remote Port Negotiation Command is send, as some deviced don't send it
#ifdef DEBUG_USB_HOST
                Notify(PSTR("\r\nRFCOMM Connection is now established - Automatic\r\n"), 0x80);
#endif
                onInit();
        }
        send(); // Send all bytes currently in the buffer
}

void SPP::onInit() {
        creditSent = false;
        waitForLastCommand = false;
        connected = true; // The RFCOMM channel is now established
        sppIndex = 0;
        if(pFuncOnInit)
                pFuncOnInit(); // Call the user function
};

void SPP::SDP_task() {
        switch(l2cap_sdp_state) {
                case L2CAP_SDP_WAIT:
                        if(l2cap_check_flag(L2CAP_FLAG_CONNECTION_SDP_REQUEST)) {
                                l2cap_clear_flag(L2CAP_FLAG_CONNECTION_SDP_REQUEST); // Clear flag
#ifdef DEBUG_USB_HOST
                                Notify(PSTR("\r\nSDP Incoming Connection Request"), 0x80);
#endif
                                pBtd->l2cap_connection_response(hci_handle, identifier, sdp_dcid, sdp_scid, PENDING);
                                delay(1);
                                pBtd->l2cap_connection_response(hci_handle, identifier, sdp_dcid, sdp_scid, SUCCESSFUL);
                                identifier++;
                                delay(1);
                                pBtd->l2cap_config_request(hci_handle, identifier, sdp_scid);
                                l2cap_sdp_state = L2CAP_SDP_SUCCESS;
                        } else if(l2cap_check_flag(L2CAP_FLAG_DISCONNECT_SDP_REQUEST)) {
                                l2cap_clear_flag(L2CAP_FLAG_DISCONNECT_SDP_REQUEST); // Clear flag
                                SDPConnected = false;
#ifdef DEBUG_USB_HOST
                                Notify(PSTR("\r\nDisconnected SDP Channel"), 0x80);
#endif
                                pBtd->l2cap_disconnection_response(hci_handle, identifier, sdp_dcid, sdp_scid);
                        }
                        break;
                case L2CAP_SDP_SUCCESS:
                        if(l2cap_check_flag(L2CAP_FLAG_CONFIG_SDP_SUCCESS)) {
                                l2cap_clear_flag(L2CAP_FLAG_CONFIG_SDP_SUCCESS); // Clear flag
#ifdef DEBUG_USB_HOST
                                Notify(PSTR("\r\nSDP Successfully Configured"), 0x80);
#endif
                                firstMessage = true; // Reset bool
                                SDPConnected = true;
                                l2cap_sdp_state = L2CAP_SDP_WAIT;
                        }
                        break;

                case L2CAP_DISCONNECT_RESPONSE: // This is for both disconnection response from the RFCOMM and SDP channel if they were connected
                        if(l2cap_check_flag(L2CAP_FLAG_DISCONNECT_RESPONSE)) {
#ifdef DEBUG_USB_HOST
                                Notify(PSTR("\r\nDisconnected L2CAP Connection"), 0x80);
#endif
                                pBtd->hci_disconnect(hci_handle);
                                hci_handle = -1; // Reset handle
                                Reset();
                        }
                        break;
        }
}

void SPP::RFCOMM_task() {
        switch(l2cap_rfcomm_state) {
                case L2CAP_RFCOMM_WAIT:
                        if(l2cap_check_flag(L2CAP_FLAG_CONNECTION_RFCOMM_REQUEST)) {
                                l2cap_clear_flag(L2CAP_FLAG_CONNECTION_RFCOMM_REQUEST); // Clear flag
#ifdef DEBUG_USB_HOST
                                Notify(PSTR("\r\nRFCOMM Incoming Connection Request"), 0x80);
#endif
                                pBtd->l2cap_connection_response(hci_handle, identifier, rfcomm_dcid, rfcomm_scid, PENDING);
                                delay(1);
                                pBtd->l2cap_connection_response(hci_handle, identifier, rfcomm_dcid, rfcomm_scid, SUCCESSFUL);
                                identifier++;
                                delay(1);
                                pBtd->l2cap_config_request(hci_handle, identifier, rfcomm_scid);
                                l2cap_rfcomm_state = L2CAP_RFCOMM_SUCCESS;
                        } else if(l2cap_check_flag(L2CAP_FLAG_DISCONNECT_RFCOMM_REQUEST)) {
                                l2cap_clear_flag(L2CAP_FLAG_DISCONNECT_RFCOMM_REQUEST); // Clear flag
                                RFCOMMConnected = false;
                                connected = false;
#ifdef DEBUG_USB_HOST
                                Notify(PSTR("\r\nDisconnected RFCOMM Channel"), 0x80);
#endif
                                pBtd->l2cap_disconnection_response(hci_handle, identifier, rfcomm_dcid, rfcomm_scid);
                        }
                        break;
                case L2CAP_RFCOMM_SUCCESS:
                        if(l2cap_check_flag(L2CAP_FLAG_CONFIG_RFCOMM_SUCCESS)) {
                                l2cap_clear_flag(L2CAP_FLAG_CONFIG_RFCOMM_SUCCESS); // Clear flag
#ifdef DEBUG_USB_HOST
                                Notify(PSTR("\r\nRFCOMM Successfully Configured"), 0x80);
#endif
                                rfcommAvailable = 0; // Reset number of bytes available
                                bytesRead = 0; // Reset number of bytes received
                                RFCOMMConnected = true;
                                l2cap_rfcomm_state = L2CAP_RFCOMM_WAIT;
                        }
                        break;
        }
}
/************************************************************/
/*                    SDP Commands                          */

/************************************************************/
void SPP::SDP_Command(uint8_t* data, uint8_t nbytes) { // See page 223 in the Bluetooth specs
        pBtd->L2CAP_Command(hci_handle, data, nbytes, sdp_scid[0], sdp_scid[1]);
}

void SPP::serviceNotSupported(uint8_t transactionIDHigh, uint8_t transactionIDLow) { // See page 235 in the Bluetooth specs
        l2capoutbuf[0] = SDP_SERVICE_SEARCH_ATTRIBUTE_RESPONSE_PDU;
        l2capoutbuf[1] = transactionIDHigh;
        l2capoutbuf[2] = transactionIDLow;
        l2capoutbuf[3] = 0x00; // MSB Parameter Length
        l2capoutbuf[4] = 0x05; // LSB Parameter Length = 5
        l2capoutbuf[5] = 0x00; // MSB AttributeListsByteCount
        l2capoutbuf[6] = 0x02; // LSB AttributeListsByteCount = 2

        /* Attribute ID/Value Sequence: */
        l2capoutbuf[7] = 0x35; // Data element sequence - length in next byte
        l2capoutbuf[8] = 0x00; // Length = 0
        l2capoutbuf[9] = 0x00; // No continuation state

        SDP_Command(l2capoutbuf, 10);
}

void SPP::serialPortResponse1(uint8_t transactionIDHigh, uint8_t transactionIDLow) {
        l2capoutbuf[0] = SDP_SERVICE_SEARCH_ATTRIBUTE_RESPONSE_PDU;
        l2capoutbuf[1] = transactionIDHigh;
        l2capoutbuf[2] = transactionIDLow;
        l2capoutbuf[3] = 0x00; // MSB Parameter Length
        l2capoutbuf[4] = 0x2B; // LSB Parameter Length = 43
        l2capoutbuf[5] = 0x00; // MSB AttributeListsByteCount
        l2capoutbuf[6] = 0x26; // LSB AttributeListsByteCount = 38

        /* Attribute ID/Value Sequence: */
        l2capoutbuf[7] = 0x36; // Data element sequence - length in next two bytes
        l2capoutbuf[8] = 0x00; // MSB Length
        l2capoutbuf[9] = 0x3C; // LSB Length = 60

        l2capoutbuf[10] = 0x36; // Data element sequence - length in next two bytes
        l2capoutbuf[11] = 0x00; // MSB Length
        l2capoutbuf[12] = 0x39; // LSB Length = 57

        l2capoutbuf[13] = 0x09; // Unsigned Integer - length 2 bytes
        l2capoutbuf[14] = 0x00; // MSB ServiceRecordHandle
        l2capoutbuf[15] = 0x00; // LSB ServiceRecordHandle
        l2capoutbuf[16] = 0x0A; // Unsigned int - length 4 bytes
        l2capoutbuf[17] = 0x00; // ServiceRecordHandle value - TODO: Is this related to HCI_Handle?
        l2capoutbuf[18] = 0x01;
        l2capoutbuf[19] = 0x00;
        l2capoutbuf[20] = 0x06;

        l2capoutbuf[21] = 0x09; // Unsigned Integer - length 2 bytes
        l2capoutbuf[22] = 0x00; // MSB ServiceClassIDList
        l2capoutbuf[23] = 0x01; // LSB ServiceClassIDList
        l2capoutbuf[24] = 0x35; // Data element sequence - length in next byte
        l2capoutbuf[25] = 0x03; // Length = 3
        l2capoutbuf[26] = 0x19; // UUID (universally unique identifier) - length = 2 bytes
        l2capoutbuf[27] = 0x11; // MSB SerialPort
        l2capoutbuf[28] = 0x01; // LSB SerialPort

        l2capoutbuf[29] = 0x09; // Unsigned Integer - length 2 bytes
        l2capoutbuf[30] = 0x00; // MSB ProtocolDescriptorList
        l2capoutbuf[31] = 0x04; // LSB ProtocolDescriptorList
        l2capoutbuf[32] = 0x35; // Data element sequence - length in next byte
        l2capoutbuf[33] = 0x0C; // Length = 12

        l2capoutbuf[34] = 0x35; // Data element sequence - length in next byte
        l2capoutbuf[35] = 0x03; // Length = 3
        l2capoutbuf[36] = 0x19; // UUID (universally unique identifier) - length = 2 bytes
        l2capoutbuf[37] = 0x01; // MSB L2CAP
        l2capoutbuf[38] = 0x00; // LSB L2CAP

        l2capoutbuf[39] = 0x35; // Data element sequence - length in next byte
        l2capoutbuf[40] = 0x05; // Length = 5
        l2capoutbuf[41] = 0x19; // UUID (universally unique identifier) - length = 2 bytes
        l2capoutbuf[42] = 0x00; // MSB RFCOMM
        l2capoutbuf[43] = 0x03; // LSB RFCOMM
        l2capoutbuf[44] = 0x08; // Unsigned Integer - length 1 byte

        l2capoutbuf[45] = 0x02; // ContinuationState - Two more bytes
        l2capoutbuf[46] = 0x00; // MSB length
        l2capoutbuf[47] = 0x19; // LSB length = 25 more bytes to come

        SDP_Command(l2capoutbuf, 48);
}

void SPP::serialPortResponse2(uint8_t transactionIDHigh, uint8_t transactionIDLow) {
        l2capoutbuf[0] = SDP_SERVICE_SEARCH_ATTRIBUTE_RESPONSE_PDU;
        l2capoutbuf[1] = transactionIDHigh;
        l2capoutbuf[2] = transactionIDLow;
        l2capoutbuf[3] = 0x00; // MSB Parameter Length
        l2capoutbuf[4] = 0x1C; // LSB Parameter Length = 28
        l2capoutbuf[5] = 0x00; // MSB AttributeListsByteCount
        l2capoutbuf[6] = 0x19; // LSB AttributeListsByteCount = 25

        /* Attribute ID/Value Sequence: */
        l2capoutbuf[7] = 0x01; // Channel 1 - TODO: Try different values, so multiple servers can be used at once

        l2capoutbuf[8] = 0x09; // Unsigned Integer - length 2 bytes
        l2capoutbuf[9] = 0x00; // MSB LanguageBaseAttributeIDList
        l2capoutbuf[10] = 0x06; // LSB LanguageBaseAttributeIDList
        l2capoutbuf[11] = 0x35; // Data element sequence - length in next byte
        l2capoutbuf[12] = 0x09; // Length = 9

        // Identifier representing the natural language = en = English - see: "ISO 639:1988"
        l2capoutbuf[13] = 0x09; // Unsigned Integer - length 2 bytes
        l2capoutbuf[14] = 0x65; // 'e'
        l2capoutbuf[15] = 0x6E; // 'n'

        // "The second element of each triplet contains an identifier that specifies a character encoding used for the language"
        // Encoding is set to 106 (UTF-8) - see: http://www.iana.org/assignments/character-sets/character-sets.xhtml
        l2capoutbuf[16] = 0x09; // Unsigned Integer - length 2 bytes
        l2capoutbuf[17] = 0x00; // MSB of character encoding
        l2capoutbuf[18] = 0x6A; // LSB of character encoding (106)

        // Attribute ID that serves as the base attribute ID for the natural language in the service record
        // "To facilitate the retrieval of human-readable universal attributes in a principal language, the base attribute ID value for the primary language supported by a service record shall be 0x0100"
        l2capoutbuf[19] = 0x09; // Unsigned Integer - length 2 bytes
        l2capoutbuf[20] = 0x01;
        l2capoutbuf[21] = 0x00;

        l2capoutbuf[22] = 0x09; // Unsigned Integer - length 2 bytes
        l2capoutbuf[23] = 0x01; // MSB ServiceDescription
        l2capoutbuf[24] = 0x00; // LSB ServiceDescription

        l2capoutbuf[25] = 0x25; // Text string - length in next byte
        l2capoutbuf[26] = 0x05; // Name length
        l2capoutbuf[27] = 'T';
        l2capoutbuf[28] = 'K';
        l2capoutbuf[29] = 'J';
        l2capoutbuf[30] = 'S';
        l2capoutbuf[31] = 'P';
        l2capoutbuf[32] = 0x00; // No continuation state

        SDP_Command(l2capoutbuf, 33);
}

void SPP::l2capResponse1(uint8_t transactionIDHigh, uint8_t transactionIDLow) {
        serialPortResponse1(transactionIDHigh, transactionIDLow); // These has to send all the supported functions, since it only supports virtual serialport it just sends the message again
}

void SPP::l2capResponse2(uint8_t transactionIDHigh, uint8_t transactionIDLow) {
        serialPortResponse2(transactionIDHigh, transactionIDLow); // Same data as serialPortResponse2
}
/************************************************************/
/*                    RFCOMM Commands                       */

/************************************************************/
void SPP::RFCOMM_Command(uint8_t* data, uint8_t nbytes) {
        pBtd->L2CAP_Command(hci_handle, data, nbytes, rfcomm_scid[0], rfcomm_scid[1]);
}

void SPP::sendRfcomm(uint8_t channel, uint8_t direction, uint8_t CR, uint8_t channelType, uint8_t pfBit, uint8_t* data, uint8_t length) {
        l2capoutbuf[0] = channel | direction | CR | extendAddress; // RFCOMM Address
        l2capoutbuf[1] = channelType | pfBit; // RFCOMM Control
        l2capoutbuf[2] = length << 1 | 0x01; // Length and format (always 0x01 bytes format)
        uint8_t i = 0;
        for(; i < length; i++)
                l2capoutbuf[i + 3] = data[i];
        l2capoutbuf[i + 3] = calcFcs(l2capoutbuf);
#ifdef EXTRADEBUG
        Notify(PSTR(" - RFCOMM Data: "), 0x80);
        for(i = 0; i < length + 4; i++) {
                D_PrintHex<uint8_t > (l2capoutbuf[i], 0x80);
                Notify(PSTR(" "), 0x80);
        }
#endif
        RFCOMM_Command(l2capoutbuf, length + 4);
}

void SPP::sendRfcommCredit(uint8_t channel, uint8_t direction, uint8_t CR, uint8_t channelType, uint8_t pfBit, uint8_t credit) {
        l2capoutbuf[0] = channel | direction | CR | extendAddress; // RFCOMM Address
        l2capoutbuf[1] = channelType | pfBit; // RFCOMM Control
        l2capoutbuf[2] = 0x01; // Length = 0
        l2capoutbuf[3] = credit; // Credit
        l2capoutbuf[4] = calcFcs(l2capoutbuf);
#ifdef EXTRADEBUG
        Notify(PSTR(" - RFCOMM Credit Data: "), 0x80);
        for(uint8_t i = 0; i < 5; i++) {
                D_PrintHex<uint8_t > (l2capoutbuf[i], 0x80);
                Notify(PSTR(" "), 0x80);
        }
#endif
        RFCOMM_Command(l2capoutbuf, 5);
}

/* CRC on 2 bytes */
uint8_t SPP::crc(uint8_t *data) {
        return (pgm_read_byte(&rfcomm_crc_table[pgm_read_byte(&rfcomm_crc_table[0xFF ^ data[0]]) ^ data[1]]));
}

/* Calculate FCS */
uint8_t SPP::calcFcs(uint8_t *data) {
        uint8_t temp = crc(data);
        if((data[1] & 0xEF) == RFCOMM_UIH)
                return (0xFF - temp); // FCS on 2 bytes
        else
                return (0xFF - pgm_read_byte(&rfcomm_crc_table[temp ^ data[2]])); // FCS on 3 bytes
}

/* Check FCS */
bool SPP::checkFcs(uint8_t *data, uint8_t fcs) {
        uint8_t temp = crc(data);
        if((data[1] & 0xEF) != RFCOMM_UIH)
                temp = pgm_read_byte(&rfcomm_crc_table[temp ^ data[2]]); // FCS on 3 bytes
        return (pgm_read_byte(&rfcomm_crc_table[temp ^ fcs]) == 0xCF);
}

/* Serial commands */
#if defined(ARDUINO) && ARDUINO >=100

size_t SPP::write(uint8_t data) {
        return write(&data, 1);
}
#else

void SPP::write(uint8_t data) {
        write(&data, 1);
}
#endif

#if defined(ARDUINO) && ARDUINO >=100

size_t SPP::write(const uint8_t *data, size_t size) {
#else

void SPP::write(const uint8_t *data, size_t size) {
#endif
        for(uint8_t i = 0; i < size; i++) {
                if(sppIndex >= ARRAY_SIZE(sppOutputBuffer))
                        send(); // Send the current data in the buffer
                sppOutputBuffer[sppIndex++] = data[i]; // All the bytes are put into a buffer and then send using the send() function
        }
#if defined(ARDUINO) && ARDUINO >=100
        return size;
#endif
}

void SPP::send() {
        if(!connected || !sppIndex)
                return;
        uint8_t length; // This is the length of the string we are sending
        uint8_t offset = 0; // This is used to keep track of where we are in the string

        l2capoutbuf[0] = rfcommChannelConnection | 0 | 0 | extendAddress; // RFCOMM Address
        l2capoutbuf[1] = RFCOMM_UIH; // RFCOMM Control

        while(sppIndex) { // We will run this while loop until this variable is 0
                if(sppIndex > (sizeof (l2capoutbuf) - 4)) // Check if the string is larger than the outgoing buffer
                        length = sizeof (l2capoutbuf) - 4;
                else
                        length = sppIndex;

                l2capoutbuf[2] = length << 1 | 1; // Length
                uint8_t i = 0;
                for(; i < length; i++)
                        l2capoutbuf[i + 3] = sppOutputBuffer[i + offset];
                l2capoutbuf[i + 3] = calcFcs(l2capoutbuf); // Calculate checksum

                RFCOMM_Command(l2capoutbuf, length + 4);

                sppIndex -= length;
                offset += length; // Increment the offset
        }
}

int SPP::available(void) {
        return rfcommAvailable;
};

void SPP::discard(void) {
        rfcommAvailable = 0;
}

int SPP::peek(void) {
        if(rfcommAvailable == 0) // Don't read if there is nothing in the buffer
                return -1;
        return rfcommDataBuffer[0];
}

int SPP::read(void) {
        if(rfcommAvailable == 0) // Don't read if there is nothing in the buffer
                return -1;
        uint8_t output = rfcommDataBuffer[0];
        for(uint8_t i = 1; i < rfcommAvailable; i++)
                rfcommDataBuffer[i - 1] = rfcommDataBuffer[i]; // Shift the buffer one left
        rfcommAvailable--;
        bytesRead++;
        if(bytesRead > (sizeof (rfcommDataBuffer) - 5)) { // We will send the command just before it runs out of credit
                bytesRead = 0;
                sendRfcommCredit(rfcommChannelConnection, rfcommDirection, 0, RFCOMM_UIH, 0x10, sizeof (rfcommDataBuffer)); // Send more credit
#ifdef EXTRADEBUG
                Notify(PSTR("\r\nSent "), 0x80);
                Notify((uint8_t)sizeof (rfcommDataBuffer), 0x80);
                Notify(PSTR(" more credit"), 0x80);
#endif
        }
        return output;
}