xref: /btstack/example/gatt_battery_query.c (revision 174a0c1c8d4a5183616f89c4f14b8b88926d49b0)
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__ "gatt_battery_query.c"
39 
40 // *****************************************************************************
41 /* EXAMPLE_START(gatt_battery_query): GATT Battery Client
42  *
43  */
44 
45 #include <stdint.h>
46 #include <stdio.h>
47 #include <stdlib.h>
48 #include <string.h>
49 
50 #include "btstack.h"
51 
52 // gatt_battery_query.gatt contains the declaration of the provided GATT Services + Characteristics
53 // gatt_battery_query.h    contains the binary representation of gatt_battery_query.gatt
54 // it is generated by the build system by calling: $BTSTACK_ROOT/tool/compile_gatt.py gatt_battery_query.gatt gatt_battery_query.h
55 // it needs to be regenerated when the GATT Database declared in gatt_battery_query.gatt file is modified
56 #include "gatt_battery_query.h"
57 
58 typedef struct advertising_report {
59     uint8_t   type;
60     uint8_t   event_type;
61     uint8_t   address_type;
62     bd_addr_t address;
63     uint8_t   rssi;
64     uint8_t   length;
65     const uint8_t * data;
66 } advertising_report_t;
67 
68 
69 typedef enum {
70     TC_IDLE,
71     TC_W4_SCAN_RESULT,
72     TC_W4_CONNECT,
73     TC_W4_SERVICE_RESULT,
74     TC_W4_CHARACTERISTIC_RESULT,
75     TC_W4_BATTERY_DATA
76 } gc_state_t;
77 
78 static int blacklist_index = 0;
79 static bd_addr_t blacklist[20];
80 static advertising_report_t report;
81 
82 static void handle_gatt_client_event(uint8_t packet_type, uint16_t channel, uint8_t *packet, uint16_t size);
83 
84 static bd_addr_t cmdline_addr;
85 static int cmdline_addr_found = 0;
86 
87 static hci_con_handle_t connection_handle;
88 static uint16_t battery_service_cid;
89 static gatt_client_characteristic_t battery_level_characteristic;
90 
91 static gc_state_t state = TC_IDLE;
92 static btstack_packet_callback_registration_t hci_event_callback_registration;
93 
94 static gatt_client_notification_t notification_listener;
95 static int listener_registered;
96 
97 static void printUUID(uint8_t * uuid128, uint16_t uuid16){
98     if (uuid16){
99         printf("%04x",uuid16);
100     } else {
101         printf("%s", uuid128_to_str(uuid128));
102     }
103 }
104 
105 static int blacklist_size(void){
106     return sizeof(blacklist) / sizeof(bd_addr_t);
107 }
108 
109 static int blacklist_contains(bd_addr_t addr){
110     int i;
111     for (i=0; i<blacklist_size(); i++){
112         if (bd_addr_cmp(addr, blacklist[i]) == 0) return 1;
113     }
114     return 0;
115 }
116 
117 static void add_to_blacklist(bd_addr_t addr){
118     printf("%s added to blacklist (no battery service found\n", bd_addr_to_str(addr));
119     bd_addr_copy(blacklist[blacklist_index], addr);
120     blacklist_index = (blacklist_index + 1) % blacklist_size();
121 }
122 
123 static void dump_advertising_report(advertising_report_t * e){
124     printf("    * adv. event: evt-type %u, addr-type %u, addr %s, rssi %u, length adv %u, data: ", e->event_type,
125            e->address_type, bd_addr_to_str(e->address), e->rssi, e->length);
126     printf_hexdump(e->data, e->length);
127 
128 }
129 
130 static void dump_characteristic_value(uint8_t * blob, uint16_t blob_length){
131     printf("    * characteristic value of length %d *** ", blob_length );
132     printf_hexdump(blob , blob_length);
133     printf("\n");
134 }
135 
136 static void dump_characteristic(gatt_client_characteristic_t * characteristic){
137     printf("    * characteristic: [0x%04x-0x%04x-0x%04x], properties 0x%02x, uuid ",
138                             characteristic->start_handle, characteristic->value_handle, characteristic->end_handle, characteristic->properties);
139     printUUID(characteristic->uuid128, characteristic->uuid16);
140     printf("\n");
141 }
142 
143 
144 static void handle_gatt_client_event(uint8_t packet_type, uint16_t channel, uint8_t *packet, uint16_t size){
145     UNUSED(packet_type);
146     UNUSED(channel);
147     UNUSED(size);
148 
149     int status;
150     uint8_t battery_level;
151 
152     if (hci_event_packet_get_type(packet) != HCI_EVENT_GATTSERVICE_META){
153         return;
154     }
155 
156     switch (hci_event_gattservice_meta_get_subevent_code(packet)){
157         case GATTSERVICE_SUBEVENT_BATTERY_SERVICE_NUM_INSTANCES:
158             status = gattservice_subevent_battery_service_num_instances_get_status(packet);
159             switch (status){
160                 case ERROR_CODE_SUCCESS:
161                 case ERROR_CODE_PARAMETER_OUT_OF_MANDATORY_RANGE:
162                     state = TC_W4_CHARACTERISTIC_RESULT;
163                     break;
164                 default:
165                     printf("SERVICE_QUERY_RESULT - Error status %x.\n", packet[4]);
166                     add_to_blacklist(report.address);
167                     gap_disconnect(connection_handle);
168                     break;
169             }
170             break;
171         default:
172             break;
173     }
174 
175 
176     switch(state){
177 
178         case TC_W4_CHARACTERISTIC_RESULT:
179             switch(hci_event_packet_get_type(packet)){
180                 case GATT_EVENT_CHARACTERISTIC_QUERY_RESULT:
181                     gatt_event_characteristic_query_result_get_characteristic(packet, &battery_level_characteristic);
182                     dump_characteristic(&battery_level_characteristic);
183                     break;
184                 case GATT_EVENT_QUERY_COMPLETE:
185                     if (packet[4] != 0){
186                         printf("CHARACTERISTIC_QUERY_RESULT - Error status %x.\n", packet[4]);
187                         add_to_blacklist(report.address);
188                         gap_disconnect(connection_handle);
189                         break;
190                     }
191 
192                     // register handler for notifications
193                     listener_registered = 1;
194                     gatt_client_listen_for_characteristic_value_updates(&notification_listener, handle_gatt_client_event, connection_handle, &battery_level_characteristic);
195 
196                     state = TC_W4_BATTERY_DATA;
197                     printf("\nConfigure battery level characteristic for notify.\n");
198                     status = gatt_client_write_client_characteristic_configuration(handle_gatt_client_event, connection_handle, &battery_level_characteristic, GATT_CLIENT_CHARACTERISTICS_CONFIGURATION_NOTIFICATION);
199                     if (status != 0){
200                         printf("\nNotification not supported. Query value of characteristic.\n");
201                         gatt_client_read_value_of_characteristic(handle_gatt_client_event, connection_handle, &battery_level_characteristic);
202                     }
203 
204                     break;
205                 default:
206                     break;
207             }
208             break;
209         case TC_W4_BATTERY_DATA:
210             switch(hci_event_packet_get_type(packet)){
211                 case GATT_EVENT_NOTIFICATION:
212                     printf("\nBattery Data:\n");
213                     dump_characteristic_value(&packet[8], little_endian_read_16(packet, 6));
214                     break;
215                 case GATT_EVENT_CHARACTERISTIC_VALUE_QUERY_RESULT:
216 
217                         if (gatt_event_characteristic_value_query_result_get_value_length(packet) < 1) break;
218                         battery_level = gatt_event_characteristic_value_query_result_get_value(packet)[0];
219                         printf("Battery level %d \n", battery_level);
220                     break;
221 
222                 case GATT_EVENT_QUERY_COMPLETE:
223                     if (packet[4] != 0){
224                         printf("CHARACTERISTIC_VALUE_QUERY_RESULT - Error status %x.\n", packet[4]);
225                         break;
226                     }
227                     break;
228                 default:
229                     printf("Unknown packet type %x\n", hci_event_packet_get_type(packet));
230                     break;
231             }
232             break;
233 
234         default:
235             printf("error\n");
236             break;
237     }
238 
239 }
240 
241 static void fill_advertising_report_from_packet(advertising_report_t * adv_report, uint8_t *packet){
242     gap_event_advertising_report_get_address(packet, adv_report->address);
243     adv_report->event_type = gap_event_advertising_report_get_advertising_event_type(packet);
244     adv_report->address_type = gap_event_advertising_report_get_address_type(packet);
245     adv_report->rssi = gap_event_advertising_report_get_rssi(packet);
246     adv_report->length = gap_event_advertising_report_get_data_length(packet);
247     adv_report->data = gap_event_advertising_report_get_data(packet);
248 }
249 
250 static void hci_event_handler(uint8_t packet_type, uint16_t channel, uint8_t *packet, uint16_t size){
251     UNUSED(channel);
252     UNUSED(size);
253 
254     if (packet_type != HCI_EVENT_PACKET) return;
255     uint8_t status;
256 
257     uint8_t event = hci_event_packet_get_type(packet);
258     switch (event) {
259         case BTSTACK_EVENT_STATE:
260             // BTstack activated, get started
261             if (btstack_event_state_get_state(packet) != HCI_STATE_WORKING) break;
262             if (cmdline_addr_found){
263                 printf("Connect to %s\n", bd_addr_to_str(cmdline_addr));
264                 state = TC_W4_CONNECT;
265                 gap_connect(cmdline_addr, 0);
266                 break;
267             }
268             printf("Start scanning!\n");
269             state = TC_W4_SCAN_RESULT;
270             gap_set_scan_parameters(0,0x0030, 0x0030);
271             gap_start_scan();
272             break;
273         case GAP_EVENT_ADVERTISING_REPORT:
274             if (state != TC_W4_SCAN_RESULT) return;
275             fill_advertising_report_from_packet(&report, packet);
276 
277             if (blacklist_contains(report.address)) {
278                 break;
279             }
280             dump_advertising_report(&report);
281             // stop scanning, and connect to the device
282             state = TC_W4_CONNECT;
283             gap_stop_scan();
284             printf("Stop scan. Connect to device with addr %s.\n", bd_addr_to_str(report.address));
285             gap_connect(report.address,report.address_type);
286 
287             break;
288         case HCI_EVENT_LE_META:
289             // wait for connection complete
290             if (hci_event_le_meta_get_subevent_code(packet) !=  HCI_SUBEVENT_LE_CONNECTION_COMPLETE) break;
291             if (state != TC_W4_CONNECT) return;
292             connection_handle = hci_subevent_le_connection_complete_get_connection_handle(packet);
293             // initialize gatt client context with handle, and add it to the list of active clients
294             // query primary services
295             printf("\nSearch for battery service.\n");
296             status = battery_service_client_connect(connection_handle, handle_gatt_client_event, &battery_service_cid);
297             if (status == ERROR_CODE_SUCCESS){
298                 state = TC_W4_SERVICE_RESULT;
299             }
300             break;
301         case HCI_EVENT_DISCONNECTION_COMPLETE:
302             // unregister listener
303             connection_handle = HCI_CON_HANDLE_INVALID;
304             if (listener_registered){
305                 listener_registered = 0;
306                 gatt_client_stop_listening_for_characteristic_value_updates(&notification_listener);
307             }
308 
309             if (cmdline_addr_found){
310                 printf("\nDisconnected %s\n", bd_addr_to_str(cmdline_addr));
311                 return;
312             }
313 
314             printf("\nDisconnected %s\n", bd_addr_to_str(report.address));
315             printf("Restart scan.\n");
316             state = TC_W4_SCAN_RESULT;
317             gap_start_scan();
318             break;
319         default:
320             break;
321     }
322 }
323 
324 #ifdef HAVE_BTSTACK_STDIN
325 static void usage(const char *name){
326     fprintf(stderr, "\nUsage: %s [-a|--address aa:bb:cc:dd:ee:ff]\n", name);
327     fprintf(stderr, "If no argument is provided, GATT browser will start scanning and connect to the first found device.\nTo connect to a specific device use argument [-a].\n\n");
328 }
329 #endif
330 
331 int btstack_main(int argc, const char * argv[]);
332 int btstack_main(int argc, const char * argv[]){
333 
334 #ifdef HAVE_BTSTACK_STDIN
335     int arg = 1;
336     cmdline_addr_found = 0;
337 
338     while (arg < argc) {
339         if(!strcmp(argv[arg], "-a") || !strcmp(argv[arg], "--address")){
340             arg++;
341             cmdline_addr_found = sscanf_bd_addr(argv[arg], cmdline_addr);
342             arg++;
343             if (!cmdline_addr_found) exit(1);
344             continue;
345         }
346         usage(argv[0]);
347         return 0;
348     }
349 #else
350     (void)argc;
351     (void)argv;
352 #endif
353     l2cap_init();
354 
355     // setup ATT server - only needed if LE Peripheral does ATT queries on its own, e.g. Android phones
356     att_server_init(profile_data, NULL, NULL);
357 
358     // GATT Client setup
359     gatt_client_init();
360     battery_service_client_init();
361 
362     sm_init();
363     sm_set_io_capabilities(IO_CAPABILITY_NO_INPUT_NO_OUTPUT);
364 
365     hci_event_callback_registration.callback = &hci_event_handler;
366     hci_add_event_handler(&hci_event_callback_registration);
367 
368 
369     // turn on!
370     hci_power_control(HCI_POWER_ON);
371 
372     return 0;
373 }
374 
375 /* EXAMPLE_END */
376 
377 
378