xref: /btstack/example/nordic_spp_le_streamer.c (revision a63a688a17f99dbda8c058261d1f192446f5ebad)
1 /*
2  * Copyright (C) 2014 BlueKitchen GmbH
3  *
4  * Redistribution and use in source and binary forms, with or without
5  * modification, are permitted provided that the following conditions
6  * are met:
7  *
8  * 1. Redistributions of source code must retain the above copyright
9  *    notice, this list of conditions and the following disclaimer.
10  * 2. Redistributions in binary form must reproduce the above copyright
11  *    notice, this list of conditions and the following disclaimer in the
12  *    documentation and/or other materials provided with the distribution.
13  * 3. Neither the name of the copyright holders nor the names of
14  *    contributors may be used to endorse or promote products derived
15  *    from this software without specific prior written permission.
16  * 4. Any redistribution, use, or modification is done solely for
17  *    personal benefit and not for any commercial purpose or for
18  *    monetary gain.
19  *
20  * THIS SOFTWARE IS PROVIDED BY BLUEKITCHEN GMBH AND CONTRIBUTORS
21  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
22  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
23  * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL MATTHIAS
24  * RINGWALD OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
25  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
26  * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
27  * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
28  * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
29  * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF
30  * THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
31  * SUCH DAMAGE.
32  *
33  * Please inquire about commercial licensing options at
34  * [email protected]
35  *
36  */
37 
38 #define __BTSTACK_FILE__ "nordic_spp_le_streamer.c"
39 
40 // *****************************************************************************
41 /* EXAMPLE_START(nordic_spp_le_streamer): LE Streamer - Stream data over GATT.
42  *
43  * @text All newer operating systems provide GATT Client functionality.
44  * This example shows how to get a maximal throughput via BLE:
45  * - send whenever possible,
46  * - use the max ATT MTU.
47  *
48  * @text In theory, we should also update the connection parameters, but we already get
49  * a connection interval of 30 ms and there's no public way to use a shorter
50  * interval with iOS (if we're not implementing an HID device).
51  *
52  * @text Note: To start the streaming, run the example.
53  * On remote device use some GATT Explorer, e.g. LightBlue, BLExplr to enable notifications.
54  */
55  // *****************************************************************************
56 
57 #include <inttypes.h>
58 #include <stdint.h>
59 #include <stdio.h>
60 #include <stdlib.h>
61 #include <string.h>
62 
63 #include "btstack.h"
64 #include "ble/gatt-service/nordic_spp_service_server.h"
65 
66 // nordic_spp_le_streamer.gatt contains the declaration of the provided GATT Services + Characteristics
67 // nordic_spp_le_streamer.h    contains the binary representation of nordic_spp_le_streamer.gatt
68 // it is generated by the build system by calling: $BTSTACK_ROOT/tool/compile_gatt.py nordic_spp_le_streamer.gatt nordic_spp_le_streamer.h
69 // it needs to be regenerated when the GATT Database declared in nordic_spp_le_streamer.gatt file is modified
70 #include "nordic_spp_le_streamer.h"
71 
72 #define REPORT_INTERVAL_MS 3000
73 #define MAX_NR_CONNECTIONS 3
74 
75 static void  packet_handler (uint8_t packet_type, uint16_t channel, uint8_t *packet, uint16_t size);
76 
77 const uint8_t adv_data[] = {
78     // Flags general discoverable, BR/EDR not supported
79     2, BLUETOOTH_DATA_TYPE_FLAGS, 0x06,
80     // Name
81     8, BLUETOOTH_DATA_TYPE_COMPLETE_LOCAL_NAME, 'n', 'R', 'F',' ', 'S', 'P', 'P',
82     // UUID ...
83     17, BLUETOOTH_DATA_TYPE_COMPLETE_LIST_OF_128_BIT_SERVICE_CLASS_UUIDS, 0x9e, 0xca, 0xdc, 0x24, 0xe, 0xe5, 0xa9, 0xe0, 0x93, 0xf3, 0xa3, 0xb5, 0x1, 0x0, 0x40, 0x6e,
84 };
85 const uint8_t adv_data_len = sizeof(adv_data);
86 
87 static btstack_packet_callback_registration_t hci_event_callback_registration;
88 
89 // support for multiple clients
90 typedef struct {
91     char name;
92     int le_notification_enabled;
93     hci_con_handle_t connection_handle;
94     int  counter;
95     char test_data[200];
96     int  test_data_len;
97     uint32_t test_data_sent;
98     uint32_t test_data_start;
99     btstack_context_callback_registration_t send_request;
100 } nordic_spp_le_streamer_connection_t;
101 
102 static nordic_spp_le_streamer_connection_t nordic_spp_le_streamer_connections[MAX_NR_CONNECTIONS];
103 
104 // round robin sending
105 static int connection_index;
106 
107 static void init_connections(void){
108     // track connections
109     int i;
110     for (i=0;i<MAX_NR_CONNECTIONS;i++){
111         nordic_spp_le_streamer_connections[i].connection_handle = HCI_CON_HANDLE_INVALID;
112         nordic_spp_le_streamer_connections[i].name = 'A' + i;
113     }
114 }
115 
116 static nordic_spp_le_streamer_connection_t * connection_for_conn_handle(hci_con_handle_t conn_handle){
117     int i;
118     for (i=0;i<MAX_NR_CONNECTIONS;i++){
119         if (nordic_spp_le_streamer_connections[i].connection_handle == conn_handle) return &nordic_spp_le_streamer_connections[i];
120     }
121     return NULL;
122 }
123 
124 static void next_connection_index(void){
125     connection_index++;
126     if (connection_index == MAX_NR_CONNECTIONS){
127         connection_index = 0;
128     }
129 }
130 
131 /*
132  * @section Track throughput
133  * @text We calculate the throughput by setting a start time and measuring the amount of
134  * data sent. After a configurable REPORT_INTERVAL_MS, we print the throughput in kB/s
135  * and reset the counter and start time.
136  */
137 
138 /* LISTING_START(tracking): Tracking throughput */
139 
140 static void test_reset(nordic_spp_le_streamer_connection_t * context){
141     context->test_data_start = btstack_run_loop_get_time_ms();
142     context->test_data_sent = 0;
143 }
144 
145 static void test_track_sent(nordic_spp_le_streamer_connection_t * context, int bytes_sent){
146     context->test_data_sent += bytes_sent;
147     // evaluate
148     uint32_t now = btstack_run_loop_get_time_ms();
149     uint32_t time_passed = now - context->test_data_start;
150     if (time_passed < REPORT_INTERVAL_MS) return;
151     // print speed
152     int bytes_per_second = context->test_data_sent * 1000 / time_passed;
153     printf("%c: %"PRIu32" bytes sent-> %u.%03u kB/s\n", context->name, context->test_data_sent, bytes_per_second / 1000, bytes_per_second % 1000);
154 
155     // restart
156     context->test_data_start = now;
157     context->test_data_sent  = 0;
158 }
159 /* LISTING_END(tracking): Tracking throughput */
160 
161 /*
162  * @section Packet Handler
163  *
164  * @text The packet handler is used to stop the notifications and reset the MTU on connect
165  * It would also be a good place to request the connection parameter update as indicated
166  * in the commented code block.
167  */
168 
169 /* LISTING_START(packetHandler): Packet Handler */
170 static void packet_handler (uint8_t packet_type, uint16_t channel, uint8_t *packet, uint16_t size){
171     UNUSED(channel);
172     UNUSED(size);
173 
174     int mtu;
175     uint16_t conn_interval;
176     nordic_spp_le_streamer_connection_t * context;
177     switch (packet_type) {
178         case HCI_EVENT_PACKET:
179             switch (hci_event_packet_get_type(packet)) {
180                 case BTSTACK_EVENT_STATE:
181                     // BTstack activated, get started
182                     if (btstack_event_state_get_state(packet) == HCI_STATE_WORKING) {
183                         printf("To start the streaming, please run the AMB2621 Toolbox to connect.\n");
184                     }
185                     break;
186                 case HCI_EVENT_DISCONNECTION_COMPLETE:
187                     context = connection_for_conn_handle(hci_event_disconnection_complete_get_connection_handle(packet));
188                     if (!context) break;
189                     // free connection
190                     printf("%c: Disconnect, reason %02x\n", context->name, hci_event_disconnection_complete_get_reason(packet));
191                     context->le_notification_enabled = 0;
192                     context->connection_handle = HCI_CON_HANDLE_INVALID;
193                     break;
194                 case HCI_EVENT_LE_META:
195                     switch (hci_event_le_meta_get_subevent_code(packet)) {
196                         case HCI_SUBEVENT_LE_CONNECTION_COMPLETE:
197                             // setup new
198                             context = connection_for_conn_handle(HCI_CON_HANDLE_INVALID);
199                             if (!context) break;
200                             context->counter = 'A';
201                             context->test_data_len = ATT_DEFAULT_MTU - 4;   // -1 for nordic 0x01 packet type
202                             context->connection_handle = hci_subevent_le_connection_complete_get_connection_handle(packet);
203                             // print connection parameters (without using float operations)
204                             conn_interval = hci_subevent_le_connection_complete_get_conn_interval(packet);
205                             printf("%c: Connection Interval: %u.%02u ms\n", context->name, conn_interval * 125 / 100, 25 * (conn_interval & 3));
206                             printf("%c: Connection Latency: %u\n", context->name, hci_subevent_le_connection_complete_get_conn_latency(packet));
207                             break;
208                     }
209                     break;
210                 case ATT_EVENT_MTU_EXCHANGE_COMPLETE:
211                     mtu = att_event_mtu_exchange_complete_get_MTU(packet) - 3;
212                     context = connection_for_conn_handle(att_event_mtu_exchange_complete_get_handle(packet));
213                     if (!context) break;
214                     context->test_data_len = btstack_min(mtu - 3, sizeof(context->test_data));
215                     printf("%c: ATT MTU = %u => use test data of len %u\n", context->name, mtu, context->test_data_len);
216                     break;
217                 default:
218                     break;
219             }
220     }
221 }
222 
223 /* LISTING_END */
224 /*
225  * @section Streamer
226  *
227  * @text The streamer function checks if notifications are enabled and if a notification can be sent now.
228  * It creates some test data - a single letter that gets increased every time - and tracks the data sent.
229  */
230 
231  /* LISTING_START(streamer): Streaming code */
232 static void nordic_can_send(void * some_context){
233     UNUSED(some_context);
234 
235     // find next active streaming connection
236     int old_connection_index = connection_index;
237     while (1){
238         // active found?
239         if ((nordic_spp_le_streamer_connections[connection_index].connection_handle != HCI_CON_HANDLE_INVALID) &&
240             (nordic_spp_le_streamer_connections[connection_index].le_notification_enabled)) break;
241 
242         // check next
243         next_connection_index();
244 
245         // none found
246         if (connection_index == old_connection_index) return;
247     }
248 
249     nordic_spp_le_streamer_connection_t * context = &nordic_spp_le_streamer_connections[connection_index];
250 
251     // create test data
252     context->counter++;
253     if (context->counter > 'Z') context->counter = 'A';
254     memset(context->test_data, context->counter, context->test_data_len);
255 
256     // send
257     nordic_spp_service_server_send(context->connection_handle, (uint8_t*) context->test_data, context->test_data_len);
258 
259     // track
260     test_track_sent(context, context->test_data_len);
261 
262     // request next send event
263     nordic_spp_service_server_request_can_send_now(&context->send_request, context->connection_handle);
264 
265     // check next
266     next_connection_index();
267 }
268 /* LISTING_END */
269 
270 static void nordic_data_received(hci_con_handle_t tx_con_handle, const uint8_t * data, uint16_t size){
271     nordic_spp_le_streamer_connection_t * context = connection_for_conn_handle(tx_con_handle);
272 
273     if (!context) return;
274 
275     if (size == 0 && context->le_notification_enabled == 0){
276         context->le_notification_enabled = 1;
277         test_reset(context);
278         context->send_request.callback = &nordic_can_send;
279         nordic_spp_service_server_request_can_send_now(&context->send_request, context->connection_handle);
280     } else {
281         printf("RECV: ");
282         printf_hexdump(data, size);
283         test_track_sent(context, size);
284    }
285 }
286 
287 int btstack_main(void);
288 int btstack_main(void){
289     // register for HCI events
290     hci_event_callback_registration.callback = &packet_handler;
291     hci_add_event_handler(&hci_event_callback_registration);
292 
293     l2cap_init();
294 
295     // setup LE device DB
296     le_device_db_init();
297 
298     // setup SM: Display only
299     sm_init();
300 
301     // setup ATT server
302     att_server_init(profile_data, NULL, NULL);
303 
304     // setup Nordic SPP service
305     nordic_spp_service_server_init(&nordic_data_received);
306 
307     // setup advertisements
308     uint16_t adv_int_min = 0x0030;
309     uint16_t adv_int_max = 0x0030;
310     uint8_t adv_type = 0;
311     bd_addr_t null_addr;
312     memset(null_addr, 0, 6);
313     gap_advertisements_set_params(adv_int_min, adv_int_max, adv_type, 0, null_addr, 0x07, 0x00);
314     gap_advertisements_set_data(adv_data_len, (uint8_t*) adv_data);
315     gap_advertisements_enable(1);
316 
317     // init client state
318     init_connections();
319 
320     // turn on!
321 	hci_power_control(HCI_POWER_ON);
322 
323     return 0;
324 }
325 /* EXAMPLE_END */
326