xref: /btstack/example/gatt_heart_rate_client.c (revision d58a1b5f11ada8ddf896c41fff5a35e7f140c37e)
1 /*
2  * Copyright (C) 2018 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__ "gatt_heart_rate_client.c"
39 
40 // *****************************************************************************
41 /* EXAMPLE_START(gatt_heart_rate_client): Connects for Heart Rate Sensor and reports measurements */
42 // *****************************************************************************
43 
44 #include <inttypes.h>
45 #include <stdint.h>
46 #include <stdio.h>
47 #include <stdlib.h>
48 #include <string.h>
49 
50 #include "btstack.h"
51 
52 // prototypes
53 static void handle_gatt_client_event(uint8_t packet_type, uint16_t channel, uint8_t *packet, uint16_t size);
54 
55 typedef enum {
56     TC_OFF,
57     TC_IDLE,
58     TC_W4_SCAN_RESULT,
59     TC_W4_CONNECT,
60     TC_W4_SERVICE_RESULT,
61     TC_W4_HEART_RATE_MEASUREMENT_CHARACTERISTIC,
62     TC_W4_ENABLE_NOTIFICATIONS_COMPLETE,
63     TC_W4_SENSOR_LOCATION_CHARACTERISTIC,
64     TC_W4_SENSOR_LOCATION,
65     TC_CONNECTED
66 } gc_state_t;
67 
68 static const char * sensor_contact_string[] = {
69     "not supported",
70     "not supported",
71     "no/poor contact",
72     "good contact"
73 };
74 
75 static bd_addr_t cmdline_addr;
76 static int cmdline_addr_found = 0;
77 
78 // addr and type of device with correct name
79 static bd_addr_t      le_streamer_addr;
80 static bd_addr_type_t le_streamer_addr_type;
81 
82 static hci_con_handle_t connection_handle;
83 
84 static gatt_client_service_t        heart_rate_service;
85 static gatt_client_characteristic_t body_sensor_location_characteristic;
86 static gatt_client_characteristic_t heart_rate_measurement_characteristic;
87 
88 static uint8_t body_sensor_location;
89 
90 static gatt_client_notification_t notification_listener;
91 static int listener_registered;
92 
93 static gc_state_t state = TC_OFF;
94 static btstack_packet_callback_registration_t hci_event_callback_registration;
95 
96 
97 // returns 1 if name is found in advertisement
98 static int advertisement_report_contains_uuid16(uint16_t uuid16, uint8_t * advertisement_report){
99     // get advertisement from report event
100     const uint8_t * adv_data = gap_event_advertising_report_get_data(advertisement_report);
101     uint16_t        adv_len  = gap_event_advertising_report_get_data_length(advertisement_report);
102 
103     // iterate over advertisement data
104     ad_context_t context;
105     int found = 0;
106     for (ad_iterator_init(&context, adv_len, adv_data) ; ad_iterator_has_more(&context) ; ad_iterator_next(&context)){
107         uint8_t data_type    = ad_iterator_get_data_type(&context);
108         uint8_t data_size    = ad_iterator_get_data_len(&context);
109         const uint8_t * data = ad_iterator_get_data(&context);
110         int i;
111         switch (data_type){
112             case BLUETOOTH_DATA_TYPE_INCOMPLETE_LIST_OF_16_BIT_SERVICE_CLASS_UUIDS:
113             case BLUETOOTH_DATA_TYPE_COMPLETE_LIST_OF_16_BIT_SERVICE_CLASS_UUIDS:
114                 // compare common prefix
115                 for (i=0; i<data_size;i+=2){
116                     if (little_endian_read_16(data, i) == uuid16) {
117                         found = 1;
118                         break;
119                     }
120                 }
121                 break;
122             default:
123                 break;
124         }
125     }
126     return found;
127 }
128 
129 static void handle_gatt_client_event(uint8_t packet_type, uint16_t channel, uint8_t *packet, uint16_t size){
130     UNUSED(packet_type);
131     UNUSED(channel);
132     UNUSED(size);
133 
134     uint16_t heart_rate;
135     uint8_t  sensor_contact;
136 
137     switch(state){
138         case TC_W4_SERVICE_RESULT:
139             switch(hci_event_packet_get_type(packet)){
140                 case GATT_EVENT_SERVICE_QUERY_RESULT:
141                     // store service (we expect only one)
142                     gatt_event_service_query_result_get_service(packet, &heart_rate_service);
143                     break;
144                 case GATT_EVENT_QUERY_COMPLETE:
145                     if (packet[4] != 0){
146                         printf("SERVICE_QUERY_RESULT - Error status %x.\n", packet[4]);
147                         gap_disconnect(connection_handle);
148                         break;
149                     }
150                     state = TC_W4_HEART_RATE_MEASUREMENT_CHARACTERISTIC;
151                     printf("Search for Heart Rate Measurement characteristic.\n");
152                     gatt_client_discover_characteristics_for_service_by_uuid16(handle_gatt_client_event, connection_handle, &heart_rate_service, ORG_BLUETOOTH_CHARACTERISTIC_HEART_RATE_MEASUREMENT);
153                     break;
154                 default:
155                     break;
156             }
157             break;
158 
159         case TC_W4_HEART_RATE_MEASUREMENT_CHARACTERISTIC:
160             switch(hci_event_packet_get_type(packet)){
161                 case GATT_EVENT_CHARACTERISTIC_QUERY_RESULT:
162                     gatt_event_characteristic_query_result_get_characteristic(packet, &heart_rate_measurement_characteristic);
163                     break;
164                 case GATT_EVENT_QUERY_COMPLETE:
165                     if (packet[4] != 0){
166                         printf("CHARACTERISTIC_QUERY_RESULT - Error status %x.\n", packet[4]);
167                         gap_disconnect(connection_handle);
168                         break;
169                     }
170                     // register handler for notifications
171                     listener_registered = 1;
172                     gatt_client_listen_for_characteristic_value_updates(&notification_listener, handle_gatt_client_event, connection_handle, &heart_rate_measurement_characteristic);
173                     // enable notifications
174                     printf("Enable Notify on Heart Rate Measurements characteristic.\n");
175                     state = TC_W4_ENABLE_NOTIFICATIONS_COMPLETE;
176                     gatt_client_write_client_characteristic_configuration(handle_gatt_client_event, connection_handle,
177                         &heart_rate_measurement_characteristic, GATT_CLIENT_CHARACTERISTICS_CONFIGURATION_NOTIFICATION);
178                     break;
179                 default:
180                     break;
181             }
182             break;
183 
184         case TC_W4_ENABLE_NOTIFICATIONS_COMPLETE:
185             switch(hci_event_packet_get_type(packet)){
186                 case GATT_EVENT_QUERY_COMPLETE:
187                     printf("Notifications enabled, ATT status %02x\n", gatt_event_query_complete_get_att_status(packet));
188 
189                     state = TC_W4_SENSOR_LOCATION_CHARACTERISTIC;
190                     printf("Search for Sensor Location characteristic.\n");
191                     gatt_client_discover_characteristics_for_service_by_uuid16(handle_gatt_client_event, connection_handle, &heart_rate_service, ORG_BLUETOOTH_CHARACTERISTIC_BODY_SENSOR_LOCATION);
192                     break;
193                 default:
194                     break;
195             }
196             break;
197 
198 
199         case TC_W4_SENSOR_LOCATION_CHARACTERISTIC:
200             switch(hci_event_packet_get_type(packet)){
201                 case GATT_EVENT_CHARACTERISTIC_QUERY_RESULT:
202                     gatt_event_characteristic_query_result_get_characteristic(packet, &body_sensor_location_characteristic);
203                     break;
204                 case GATT_EVENT_QUERY_COMPLETE:
205                     if (packet[4] != 0){
206                         printf("CHARACTERISTIC_QUERY_RESULT - Error status %x.\n", packet[4]);
207                         state = TC_CONNECTED;
208                         break;
209                     }
210                     if (body_sensor_location_characteristic.value_handle == 0){
211                         printf("Sensor Location characteristic not available.\n");
212                         state = TC_CONNECTED;
213                         break;
214                     }
215                     state = TC_W4_HEART_RATE_MEASUREMENT_CHARACTERISTIC;
216                     printf("Read Body Sensor Location.\n");
217                     state = TC_W4_SENSOR_LOCATION;
218                     gatt_client_read_value_of_characteristic(handle_gatt_client_event, connection_handle, &body_sensor_location_characteristic);
219                     break;
220                 default:
221                     break;
222             }
223             break;
224 
225 
226         case TC_W4_SENSOR_LOCATION:
227             switch(hci_event_packet_get_type(packet)){
228                 case GATT_EVENT_CHARACTERISTIC_VALUE_QUERY_RESULT:
229                     body_sensor_location = gatt_event_characteristic_value_query_result_get_value(packet)[0];
230                     printf("Sensor Location: %u\n", body_sensor_location);
231                     break;
232                 case GATT_EVENT_QUERY_COMPLETE:
233                     state = TC_CONNECTED;
234                     break;
235                 default:
236                     break;
237             }
238             break;
239 
240         case TC_CONNECTED:
241             switch(hci_event_packet_get_type(packet)){
242                 case GATT_EVENT_NOTIFICATION:
243                     if (gatt_event_notification_get_value(packet)[0] & 1){
244                         heart_rate = little_endian_read_16(gatt_event_notification_get_value(packet), 1);
245                     } else {
246                         heart_rate = gatt_event_notification_get_value(packet)[1];
247                     }
248                     sensor_contact = (gatt_event_notification_get_value(packet)[0] >> 1) & 3;
249                     printf("Heart Rate: %3u, Sensor Contact: %s\n", heart_rate, sensor_contact_string[sensor_contact]);
250                     break;
251                 case GATT_EVENT_QUERY_COMPLETE:
252                     break;
253                 case GATT_EVENT_CAN_WRITE_WITHOUT_RESPONSE:
254                     break;
255                 default:
256                     break;
257             }
258             break;
259 
260         default:
261             break;
262     }
263 }
264 
265 // Either connect to remote specified on command line or start scan for device with Hear Rate Service in advertisement
266 static void gatt_heart_rate_client_start(void){
267     if (cmdline_addr_found){
268         printf("Connect to %s\n", bd_addr_to_str(cmdline_addr));
269         state = TC_W4_CONNECT;
270         gap_connect(cmdline_addr, 0);
271     } else {
272         printf("Start scanning!\n");
273         state = TC_W4_SCAN_RESULT;
274         gap_set_scan_parameters(0,0x0030, 0x0030);
275         gap_start_scan();
276     }
277 }
278 
279 static void hci_event_handler(uint8_t packet_type, uint16_t channel, uint8_t *packet, uint16_t size){
280     UNUSED(channel);
281     UNUSED(size);
282 
283     if (packet_type != HCI_EVENT_PACKET) return;
284 
285     uint16_t conn_interval;
286     uint8_t event = hci_event_packet_get_type(packet);
287     switch (event) {
288         case BTSTACK_EVENT_STATE:
289             // BTstack activated, get started
290             if (btstack_event_state_get_state(packet) == HCI_STATE_WORKING) {
291                 gatt_heart_rate_client_start();
292             } else {
293                 state = TC_OFF;
294             }
295             break;
296         case GAP_EVENT_ADVERTISING_REPORT:
297             if (state != TC_W4_SCAN_RESULT) return;
298             // check name in advertisement
299             if (!advertisement_report_contains_uuid16(ORG_BLUETOOTH_SERVICE_HEART_RATE, packet)) return;
300             // store address and type
301             gap_event_advertising_report_get_address(packet, le_streamer_addr);
302             le_streamer_addr_type = gap_event_advertising_report_get_address_type(packet);
303             // stop scanning, and connect to the device
304             state = TC_W4_CONNECT;
305             gap_stop_scan();
306             printf("Stop scan. Connect to device with addr %s.\n", bd_addr_to_str(le_streamer_addr));
307             gap_connect(le_streamer_addr,le_streamer_addr_type);
308             break;
309         case HCI_EVENT_LE_META:
310             // wait for connection complete
311             if (hci_event_le_meta_get_subevent_code(packet) !=  HCI_SUBEVENT_LE_CONNECTION_COMPLETE) break;
312             if (state != TC_W4_CONNECT) return;
313             connection_handle = hci_subevent_le_connection_complete_get_connection_handle(packet);
314             // print connection parameters (without using float operations)
315             conn_interval = hci_subevent_le_connection_complete_get_conn_interval(packet);
316             printf("Connection Interval: %u.%02u ms\n", conn_interval * 125 / 100, 25 * (conn_interval & 3));
317             printf("Connection Latency: %u\n", hci_subevent_le_connection_complete_get_conn_latency(packet));
318             // initialize gatt client context with handle, and add it to the list of active clients
319             // query primary services
320             printf("Search for Heart Rate service.\n");
321             state = TC_W4_SERVICE_RESULT;
322             gatt_client_discover_primary_services_by_uuid16(handle_gatt_client_event, connection_handle, ORG_BLUETOOTH_SERVICE_HEART_RATE);
323             break;
324         case HCI_EVENT_DISCONNECTION_COMPLETE:
325             // unregister listener
326             connection_handle = HCI_CON_HANDLE_INVALID;
327             if (listener_registered){
328                 listener_registered = 0;
329                 gatt_client_stop_listening_for_characteristic_value_updates(&notification_listener);
330             }
331             if (cmdline_addr_found){
332                 printf("Disconnected %s\n", bd_addr_to_str(cmdline_addr));
333                 return;
334             }
335             printf("Disconnected %s\n", bd_addr_to_str(le_streamer_addr));
336             if (state == TC_OFF) break;
337             gatt_heart_rate_client_start();
338             break;
339         default:
340             break;
341     }
342 }
343 
344 #ifdef HAVE_BTSTACK_STDIN
345 static void usage(const char *name){
346     fprintf(stderr, "Usage: %s [-a|--address aa:bb:cc:dd:ee:ff]\n", name);
347     fprintf(stderr, "If no argument is provided, GATT Heart Rate Client will start scanning and connect to the first device named 'LE Streamer'.\n");
348     fprintf(stderr, "To connect to a specific device use argument [-a].\n\n");
349 }
350 #endif
351 
352 int btstack_main(int argc, const char * argv[]);
353 int btstack_main(int argc, const char * argv[]){
354 
355 #ifdef HAVE_BTSTACK_STDIN
356     int arg = 1;
357     cmdline_addr_found = 0;
358 
359     while (arg < argc) {
360         if(!strcmp(argv[arg], "-a") || !strcmp(argv[arg], "--address")){
361             arg++;
362             cmdline_addr_found = sscanf_bd_addr(argv[arg], cmdline_addr);
363             arg++;
364             if (!cmdline_addr_found) exit(1);
365             continue;
366         }
367         usage(argv[0]);
368         return 0;
369     }
370 #else
371     (void)argc;
372     (void)argv;
373 #endif
374     l2cap_init();
375 
376     gatt_client_init();
377 
378     sm_init();
379     sm_set_io_capabilities(IO_CAPABILITY_NO_INPUT_NO_OUTPUT);
380 
381     hci_event_callback_registration.callback = &hci_event_handler;
382     hci_add_event_handler(&hci_event_callback_registration);
383 
384     // turn on!
385     hci_power_control(HCI_POWER_ON);
386 
387     return 0;
388 }
389 /* EXAMPLE_END */
390