/*
* Copyright (C) 2018 BlueKitchen GmbH
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. Neither the name of the copyright holders nor the names of
* contributors may be used to endorse or promote products derived
* from this software without specific prior written permission.
* 4. Any redistribution, use, or modification is done solely for
* personal benefit and not for any commercial purpose or for
* monetary gain.
*
* THIS SOFTWARE IS PROVIDED BY BLUEKITCHEN GMBH AND CONTRIBUTORS
* ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
* FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL MATTHIAS
* RINGWALD OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
* BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
* OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
* AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
* OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF
* THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
* Please inquire about commercial licensing options at
* contact@bluekitchen-gmbh.com
*
*/
#define __BTSTACK_FILE__ "gatt_heart_rate_client.c"
// *****************************************************************************
/* EXAMPLE_START(gatt_heart_rate_client): Connects for Heart Rate Sensor and reports measurements */
// *****************************************************************************
#include <inttypes.h>
#include <stdint.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include "btstack.h"
// prototypes
static void handle_gatt_client_event(uint8_t packet_type, uint16_t channel, uint8_t *packet, uint16_t size);
typedef enum {
TC_OFF,
TC_IDLE,
TC_W4_SCAN_RESULT,
TC_W4_CONNECT,
TC_W4_SERVICE_RESULT,
TC_W4_HEART_RATE_MEASUREMENT_CHARACTERISTIC,
TC_W4_ENABLE_NOTIFICATIONS_COMPLETE,
TC_W4_SENSOR_LOCATION_CHARACTERISTIC,
TC_W4_SENSOR_LOCATION,
TC_CONNECTED
} gc_state_t;
static const char * sensor_contact_string[] = {
"not supported",
"not supported",
"no/poor contact",
"good contact"
};
static bd_addr_t cmdline_addr = { };
static int cmdline_addr_found = 0;
// addr and type of device with correct name
static bd_addr_t le_streamer_addr;
static bd_addr_type_t le_streamer_addr_type;
static hci_con_handle_t connection_handle;
static gatt_client_service_t heart_rate_service;
static gatt_client_characteristic_t body_sensor_location_characteristic;
static gatt_client_characteristic_t heart_rate_measurement_characteristic;
static uint8_t body_sensor_location;
static gatt_client_notification_t notification_listener;
static int listener_registered;
static gc_state_t state = TC_OFF;
static btstack_packet_callback_registration_t hci_event_callback_registration;
// returns 1 if name is found in advertisement
static int advertisement_report_contains_uuid16(uint16_t uuid16, uint8_t * advertisement_report){
// get advertisement from report event
const uint8_t * adv_data = gap_event_advertising_report_get_data(advertisement_report);
uint16_t adv_len = gap_event_advertising_report_get_data_length(advertisement_report);
// iterate over advertisement data
ad_context_t context;
int found = 0;
for (ad_iterator_init(&context, adv_len, adv_data) ; ad_iterator_has_more(&context) ; ad_iterator_next(&context)){
uint8_t data_type = ad_iterator_get_data_type(&context);
uint8_t data_size = ad_iterator_get_data_len(&context);
const uint8_t * data = ad_iterator_get_data(&context);
int i;
switch (data_type){
case BLUETOOTH_DATA_TYPE_INCOMPLETE_LIST_OF_16_BIT_SERVICE_CLASS_UUIDS:
case BLUETOOTH_DATA_TYPE_COMPLETE_LIST_OF_16_BIT_SERVICE_CLASS_UUIDS:
// compare common prefix
for (i=0; i<data_size;i+=2){
if (little_endian_read_16(data, i) == uuid16) {
found = 1;
break;
}
}
break;
default:
break;
}
}
return found;
}
static void handle_gatt_client_event(uint8_t packet_type, uint16_t channel, uint8_t *packet, uint16_t size){
UNUSED(packet_type);
UNUSED(channel);
UNUSED(size);
uint16_t heart_rate;
uint8_t sensor_contact;
switch(state){
case TC_W4_SERVICE_RESULT:
switch(hci_event_packet_get_type(packet)){
case GATT_EVENT_SERVICE_QUERY_RESULT:
// store service (we expect only one)
gatt_event_service_query_result_get_service(packet, &heart_rate_service);
break;
case GATT_EVENT_QUERY_COMPLETE:
if (packet[4] != 0){
printf("SERVICE_QUERY_RESULT - Error status %x.\n", packet[4]);
gap_disconnect(connection_handle);
break;
}
state = TC_W4_HEART_RATE_MEASUREMENT_CHARACTERISTIC;
printf("Search for Heart Rate Measurement characteristic.\n");
gatt_client_discover_characteristics_for_service_by_uuid16(handle_gatt_client_event, connection_handle, &heart_rate_service, ORG_BLUETOOTH_CHARACTERISTIC_HEART_RATE_MEASUREMENT);
break;
default:
break;
}
break;
case TC_W4_HEART_RATE_MEASUREMENT_CHARACTERISTIC:
switch(hci_event_packet_get_type(packet)){
case GATT_EVENT_CHARACTERISTIC_QUERY_RESULT:
gatt_event_characteristic_query_result_get_characteristic(packet, &heart_rate_measurement_characteristic);
break;
case GATT_EVENT_QUERY_COMPLETE:
if (packet[4] != 0){
printf("CHARACTERISTIC_QUERY_RESULT - Error status %x.\n", packet[4]);
gap_disconnect(connection_handle);
break;
}
// register handler for notifications
listener_registered = 1;
gatt_client_listen_for_characteristic_value_updates(¬ification_listener, handle_gatt_client_event, connection_handle, &heart_rate_measurement_characteristic);
// enable notifications
printf("Enable Notify on Heart Rate Measurements characteristic.\n");
state = TC_W4_ENABLE_NOTIFICATIONS_COMPLETE;
gatt_client_write_client_characteristic_configuration(handle_gatt_client_event, connection_handle,
&heart_rate_measurement_characteristic, GATT_CLIENT_CHARACTERISTICS_CONFIGURATION_NOTIFICATION);
break;
default:
break;
}
break;
case TC_W4_ENABLE_NOTIFICATIONS_COMPLETE:
switch(hci_event_packet_get_type(packet)){
case GATT_EVENT_QUERY_COMPLETE:
printf("Notifications enabled, status %02x\n", gatt_event_query_complete_get_status(packet));
state = TC_W4_SENSOR_LOCATION_CHARACTERISTIC;
printf("Search for Sensor Location characteristic.\n");
gatt_client_discover_characteristics_for_service_by_uuid16(handle_gatt_client_event, connection_handle, &heart_rate_service, ORG_BLUETOOTH_CHARACTERISTIC_BODY_SENSOR_LOCATION);
break;
default:
break;
}
break;
case TC_W4_SENSOR_LOCATION_CHARACTERISTIC:
switch(hci_event_packet_get_type(packet)){
case GATT_EVENT_CHARACTERISTIC_QUERY_RESULT:
gatt_event_characteristic_query_result_get_characteristic(packet, &body_sensor_location_characteristic);
break;
case GATT_EVENT_QUERY_COMPLETE:
if (packet[4] != 0){
printf("CHARACTERISTIC_QUERY_RESULT - Error status %x.\n", packet[4]);
state = TC_CONNECTED;
break;
}
state = TC_W4_HEART_RATE_MEASUREMENT_CHARACTERISTIC;
printf("Read Body Sensor Location.\n");
state = TC_W4_SENSOR_LOCATION;
gatt_client_read_value_of_characteristic(handle_gatt_client_event, connection_handle, &body_sensor_location_characteristic);
break;
default:
break;
}
break;
case TC_W4_SENSOR_LOCATION:
switch(hci_event_packet_get_type(packet)){
case GATT_EVENT_CHARACTERISTIC_VALUE_QUERY_RESULT:
body_sensor_location = gatt_event_characteristic_value_query_result_get_value(packet)[0];
printf("Sensor Location: %u\n", body_sensor_location);
state = TC_CONNECTED;
break;
default:
break;
}
break;
case TC_CONNECTED:
switch(hci_event_packet_get_type(packet)){
case GATT_EVENT_NOTIFICATION:
if (gatt_event_notification_get_value(packet)[0] & 1){
heart_rate = little_endian_read_16(gatt_event_notification_get_value(packet), 1);
} else {
heart_rate = gatt_event_notification_get_value(packet)[1];
}
sensor_contact = (gatt_event_notification_get_value(packet)[0] >> 1) & 3;
printf("Heart Rate: %3u, Sensor Contact: %s\n", heart_rate, sensor_contact_string[sensor_contact]);
break;
case GATT_EVENT_QUERY_COMPLETE:
break;
case GATT_EVENT_CAN_WRITE_WITHOUT_RESPONSE:
break;
default:
break;
}
break;
default:
break;
}
}
// Either connect to remote specified on command line or start scan for device with Hear Rate Service in advertisement
static void gatt_heart_rate_client_start(void){
if (cmdline_addr_found){
printf("Connect to %s\n", bd_addr_to_str(cmdline_addr));
state = TC_W4_CONNECT;
gap_connect(cmdline_addr, 0);
} else {
printf("Start scanning!\n");
state = TC_W4_SCAN_RESULT;
gap_set_scan_parameters(0,0x0030, 0x0030);
gap_start_scan();
}
}
static void hci_event_handler(uint8_t packet_type, uint16_t channel, uint8_t *packet, uint16_t size){
UNUSED(channel);
UNUSED(size);
if (packet_type != HCI_EVENT_PACKET) return;
uint16_t conn_interval;
uint8_t event = hci_event_packet_get_type(packet);
switch (event) {
case BTSTACK_EVENT_STATE:
// BTstack activated, get started
if (btstack_event_state_get_state(packet) == HCI_STATE_WORKING) {
gatt_heart_rate_client_start();
} else {
state = TC_OFF;
}
break;
case GAP_EVENT_ADVERTISING_REPORT:
if (state != TC_W4_SCAN_RESULT) return;
// check name in advertisement
if (!advertisement_report_contains_uuid16(ORG_BLUETOOTH_SERVICE_HEART_RATE, packet)) return;
// store address and type
gap_event_advertising_report_get_address(packet, le_streamer_addr);
le_streamer_addr_type = gap_event_advertising_report_get_address_type(packet);
// stop scanning, and connect to the device
state = TC_W4_CONNECT;
gap_stop_scan();
printf("Stop scan. Connect to device with addr %s.\n", bd_addr_to_str(le_streamer_addr));
gap_connect(le_streamer_addr,le_streamer_addr_type);
break;
case HCI_EVENT_LE_META:
// wait for connection complete
if (hci_event_le_meta_get_subevent_code(packet) != HCI_SUBEVENT_LE_CONNECTION_COMPLETE) break;
if (state != TC_W4_CONNECT) return;
connection_handle = hci_subevent_le_connection_complete_get_connection_handle(packet);
// print connection parameters (without using float operations)
conn_interval = hci_subevent_le_connection_complete_get_conn_interval(packet);
printf("Connection Interval: %u.%02u ms\n", conn_interval * 125 / 100, 25 * (conn_interval & 3));
printf("Connection Latency: %u\n", hci_subevent_le_connection_complete_get_conn_latency(packet));
// initialize gatt client context with handle, and add it to the list of active clients
// query primary services
printf("Search for Heart Rate service.\n");
state = TC_W4_SERVICE_RESULT;
gatt_client_discover_primary_services_by_uuid16(handle_gatt_client_event, connection_handle, ORG_BLUETOOTH_SERVICE_HEART_RATE);
break;
case HCI_EVENT_DISCONNECTION_COMPLETE:
// unregister listener
connection_handle = HCI_CON_HANDLE_INVALID;
if (listener_registered){
listener_registered = 0;
gatt_client_stop_listening_for_characteristic_value_updates(¬ification_listener);
}
if (cmdline_addr_found){
printf("Disconnected %s\n", bd_addr_to_str(cmdline_addr));
return;
}
printf("Disconnected %s\n", bd_addr_to_str(le_streamer_addr));
if (state == TC_OFF) break;
gatt_heart_rate_client_start();
break;
default:
break;
}
}
#ifdef HAVE_BTSTACK_STDIN
static void usage(const char *name){
fprintf(stderr, "Usage: %s [-a|--address aa:bb:cc:dd:ee:ff]\n", name);
fprintf(stderr, "If no argument is provided, GATT Heart Rate Client will start scanning and connect to the first device named 'LE Streamer'.\n");
fprintf(stderr, "To connect to a specific device use argument [-a].\n\n");
}
#endif
int btstack_main(int argc, const char * argv[]);
int btstack_main(int argc, const char * argv[]){
#ifdef HAVE_BTSTACK_STDIN
int arg = 1;
cmdline_addr_found = 0;
while (arg < argc) {
if(!strcmp(argv[arg], "-a") || !strcmp(argv[arg], "--address")){
arg++;
cmdline_addr_found = sscanf_bd_addr(argv[arg], cmdline_addr);
arg++;
if (!cmdline_addr_found) exit(1);
continue;
}
usage(argv[0]);
return 0;
}
#else
(void)argc;
(void)argv;
#endif
hci_event_callback_registration.callback = &hci_event_handler;
hci_add_event_handler(&hci_event_callback_registration);
l2cap_init();
gatt_client_init();
sm_init();
sm_set_io_capabilities(IO_CAPABILITY_NO_INPUT_NO_OUTPUT);
// turn on!
hci_power_control(HCI_POWER_ON);
return 0;
}
/* EXAMPLE_END */