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__ "gap_inquiry.c" 39 40 // ***************************************************************************** 41 /* EXAMPLE_START(gap_inquiry): GAP Inquiry Example 42 * 43 * @text The Generic Access Profile (GAP) defines how Bluetooth devices discover 44 * and establish a connection with each other. In this example, the application 45 * discovers surrounding Bluetooth devices and collects their Class of Device 46 * (CoD), page scan mode, clock offset, and RSSI. After that, the remote name of 47 * each device is requested. In the following section we outline the Bluetooth 48 * logic part, i.e., how the packet handler handles the asynchronous events and 49 * data packets. 50 */ 51 // ***************************************************************************** 52 53 #include <stdint.h> 54 #include <stdio.h> 55 #include <stdlib.h> 56 #include <string.h> 57 58 #include "btstack.h" 59 60 #define MAX_DEVICES 10 61 enum DEVICE_STATE { REMOTE_NAME_REQUEST, REMOTE_NAME_INQUIRED, REMOTE_NAME_FETCHED }; 62 struct device { 63 bd_addr_t address; 64 uint16_t clockOffset; 65 uint32_t classOfDevice; 66 uint8_t pageScanRepetitionMode; 67 uint8_t rssi; 68 enum DEVICE_STATE state; 69 }; 70 71 #define INQUIRY_INTERVAL 5 72 struct device devices[MAX_DEVICES]; 73 int deviceCount = 0; 74 75 76 enum STATE {INIT, ACTIVE} ; 77 enum STATE state = INIT; 78 79 static btstack_packet_callback_registration_t hci_event_callback_registration; 80 81 static int getDeviceIndexForAddress( bd_addr_t addr){ 82 int j; 83 for (j=0; j< deviceCount; j++){ 84 if (bd_addr_cmp(addr, devices[j].address) == 0){ 85 return j; 86 } 87 } 88 return -1; 89 } 90 91 static void start_scan(void){ 92 printf("Starting inquiry scan..\n"); 93 hci_send_cmd(&hci_inquiry, HCI_INQUIRY_LAP, INQUIRY_INTERVAL, 0); 94 } 95 96 static int has_more_remote_name_requests(void){ 97 int i; 98 for (i=0;i<deviceCount;i++) { 99 if (devices[i].state == REMOTE_NAME_REQUEST) return 1; 100 } 101 return 0; 102 } 103 104 static void do_next_remote_name_request(void){ 105 int i; 106 for (i=0;i<deviceCount;i++) { 107 // remote name request 108 if (devices[i].state == REMOTE_NAME_REQUEST){ 109 devices[i].state = REMOTE_NAME_INQUIRED; 110 printf("Get remote name of %s...\n", bd_addr_to_str(devices[i].address)); 111 hci_send_cmd(&hci_remote_name_request, devices[i].address, 112 devices[i].pageScanRepetitionMode, 0, devices[i].clockOffset | 0x8000); 113 return; 114 } 115 } 116 } 117 118 static void continue_remote_names(void){ 119 if (has_more_remote_name_requests()){ 120 do_next_remote_name_request(); 121 return; 122 } 123 start_scan(); 124 } 125 126 /* @section Bluetooth Logic 127 * 128 * @text The Bluetooth logic is implemented as a state machine within the packet 129 * handler. In this example, the following states are passed sequentially: 130 * INIT, and ACTIVE. 131 */ 132 133 static void packet_handler(uint8_t packet_type, uint16_t channel, uint8_t *packet, uint16_t size){ 134 UNUSED(channel); 135 UNUSED(size); 136 137 bd_addr_t addr; 138 int i; 139 int numResponses; 140 int index; 141 142 if (packet_type != HCI_EVENT_PACKET) return; 143 144 uint8_t event = hci_event_packet_get_type(packet); 145 146 switch(state){ 147 /* @text In INIT, an inquiry scan is started, and the application transits to 148 * ACTIVE state. 149 */ 150 case INIT: 151 switch(event){ 152 case BTSTACK_EVENT_STATE: 153 if (btstack_event_state_get_state(packet) == HCI_STATE_WORKING){ 154 start_scan(); 155 state = ACTIVE; 156 } 157 break; 158 default: 159 break; 160 } 161 break; 162 163 /* @text In ACTIVE, the following events are processed: 164 * - Inquiry result event: the list of discovered devices is processed and the 165 * Class of Device (CoD), page scan mode, clock offset, and RSSI are stored in a table. 166 * - Inquiry complete event: the remote name is requested for devices without a fetched 167 * name. The state of a remote name can be one of the following: 168 * REMOTE_NAME_REQUEST, REMOTE_NAME_INQUIRED, or REMOTE_NAME_FETCHED. 169 * - Remote name cached event: prints cached remote names provided by BTstack, 170 * if persistent storage is provided. 171 * - Remote name request complete event: the remote name is stored in the table and the 172 * state is updated to REMOTE_NAME_FETCHED. The query of remote names is continued. 173 */ 174 case ACTIVE: 175 switch(event){ 176 case HCI_EVENT_INQUIRY_RESULT: 177 case HCI_EVENT_INQUIRY_RESULT_WITH_RSSI: 178 case HCI_EVENT_EXTENDED_INQUIRY_RESPONSE: 179 numResponses = hci_event_inquiry_result_get_num_responses(packet); 180 for (i=0; i<numResponses && deviceCount < MAX_DEVICES;i++){ 181 reverse_bd_addr(&packet[3 + i * 6], addr); 182 index = getDeviceIndexForAddress(addr); 183 if (index >= 0) continue; // already in our list 184 185 memcpy(devices[deviceCount].address, addr, 6); 186 devices[deviceCount].pageScanRepetitionMode = packet [3 + numResponses*(6) + i*1]; 187 if (event == HCI_EVENT_INQUIRY_RESULT){ 188 devices[deviceCount].classOfDevice = little_endian_read_24(packet, 3 + numResponses*(6+1+1+1) + i*3); 189 devices[deviceCount].clockOffset = little_endian_read_16(packet, 3 + numResponses*(6+1+1+1+3) + i*2) & 0x7fff; 190 devices[deviceCount].rssi = 0; 191 } else { 192 devices[deviceCount].classOfDevice = little_endian_read_24(packet, 3 + numResponses*(6+1+1) + i*3); 193 devices[deviceCount].clockOffset = little_endian_read_16(packet, 3 + numResponses*(6+1+1+3) + i*2) & 0x7fff; 194 devices[deviceCount].rssi = packet [3 + numResponses*(6+1+1+3+2) + i*1]; 195 } 196 devices[deviceCount].state = REMOTE_NAME_REQUEST; 197 char name_buffer[240]; 198 if (event == HCI_EVENT_EXTENDED_INQUIRY_RESPONSE){ 199 uint8_t * eir_data = &packet[3 + (6+1+1+3+2) + 1]; 200 ad_context_t context; 201 for (ad_iterator_init(&context, 240, eir_data) ; ad_iterator_has_more(&context) ; ad_iterator_next(&context)){ 202 uint8_t data_type = ad_iterator_get_data_type(&context); 203 uint8_t data_size = ad_iterator_get_data_len(&context); 204 const uint8_t * data = ad_iterator_get_data(&context); 205 // Prefer Complete Local Name over Shortend Local Name 206 switch (data_type){ 207 case BLUETOOTH_DATA_TYPE_SHORTENED_LOCAL_NAME: 208 if (devices[deviceCount].state == REMOTE_NAME_FETCHED) break; 209 case BLUETOOTH_DATA_TYPE_COMPLETE_LOCAL_NAME: 210 devices[deviceCount].state = REMOTE_NAME_FETCHED; 211 memcpy(name_buffer, data, data_size); 212 name_buffer[data_size] = 0; 213 break; 214 default: 215 break; 216 } 217 } 218 } 219 printf("Device found: %s with COD: 0x%06x, pageScan %d, clock offset 0x%04x", bd_addr_to_str(addr), 220 (unsigned int) devices[deviceCount].classOfDevice, devices[deviceCount].pageScanRepetitionMode, 221 devices[deviceCount].clockOffset); 222 if (event >= HCI_EVENT_INQUIRY_RESULT_WITH_RSSI){ 223 printf(", rssi 0x%02x", devices[deviceCount].rssi); 224 } 225 if (devices[deviceCount].state == REMOTE_NAME_FETCHED){ 226 printf(", name '%s'", name_buffer); 227 } 228 printf("\n"); 229 deviceCount++; 230 } 231 break; 232 233 case HCI_EVENT_INQUIRY_COMPLETE: 234 for (i=0;i<deviceCount;i++) { 235 // retry remote name request 236 if (devices[i].state == REMOTE_NAME_INQUIRED) 237 devices[i].state = REMOTE_NAME_REQUEST; 238 } 239 continue_remote_names(); 240 break; 241 242 case HCI_EVENT_REMOTE_NAME_REQUEST_COMPLETE: 243 reverse_bd_addr(&packet[3], addr); 244 index = getDeviceIndexForAddress(addr); 245 if (index >= 0) { 246 if (packet[2] == 0) { 247 printf("Name: '%s'\n", &packet[9]); 248 devices[index].state = REMOTE_NAME_FETCHED; 249 } else { 250 printf("Failed to get name: page timeout\n"); 251 } 252 } 253 continue_remote_names(); 254 break; 255 256 default: 257 break; 258 } 259 break; 260 261 default: 262 break; 263 } 264 } 265 266 /* @text For more details on discovering remote devices, please see 267 * Section on [GAP](../profiles/#sec:GAPdiscoverRemoteDevices). 268 */ 269 270 271 /* @section Main Application Setup 272 * 273 * @text Listing MainConfiguration shows main application code. 274 * It registers the HCI packet handler and starts the Bluetooth stack. 275 */ 276 277 /* LISTING_START(MainConfiguration): Setup packet handler for GAP inquiry */ 278 int btstack_main(int argc, const char * argv[]); 279 int btstack_main(int argc, const char * argv[]) { 280 (void)argc; 281 (void)argv; 282 283 hci_event_callback_registration.callback = &packet_handler; 284 hci_add_event_handler(&hci_event_callback_registration); 285 286 // enabled EIR 287 hci_set_inquiry_mode(INQUIRY_MODE_RSSI_AND_EIR); 288 289 // turn on! 290 hci_power_control(HCI_POWER_ON); 291 292 return 0; 293 } 294 /* LISTING_END */ 295 /* EXAMPLE_END */ 296