btstack/example/embedded/gatt_battery_query.c

/*
 * Copyright (C) 2014 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
 *
 */

// *****************************************************************************
//
// BLE Client
//
// *****************************************************************************

#include <stdint.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include "run_loop.h"
#include "hci_cmds.h"
#include "utils.h"
#include "btstack-config.h"

#include "debug.h"
#include "btstack_memory.h"
#include "hci.h"
#include "hci_dump.h"
#include "l2cap.h"

#include "ble/att.h"
#include "ble/gatt_client.h"
#include "ble/ad_parser.h"
#include "ble/sm.h"

typedef struct advertising_report {
    uint8_t   type;
    uint8_t   event_type;
    uint8_t   address_type;
    bd_addr_t address;
    uint8_t   rssi;
    uint8_t   length;
    uint8_t * data;
} advertising_report_t;


typedef enum {
    TC_IDLE,
    TC_W4_SCAN_RESULT,
    TC_W4_CONNECT,
    TC_W4_SERVICE_RESULT,
    TC_W4_CHARACTERISTIC_RESULT,
    TC_W4_BATTERY_DATA
} gc_state_t;

static bd_addr_t cmdline_addr = { };
static int cmdline_addr_found = 0;

uint16_t gc_id, gc_handle;
static uint16_t battery_service_uuid = 0x180F;
static uint16_t battery_level_characteristic_uuid = 0x2a19;
static le_service_t battery_service;
static le_characteristic_t config_characteristic;
    
static gc_state_t state = TC_IDLE;

static void printUUID(uint8_t * uuid128, uint16_t uuid16){
    if (uuid16){
        printf("%04x",uuid16);
    } else {
        printUUID128(uuid128);
    }
}

static void dump_advertising_report(advertising_report_t * e){
    printf("    * adv. event: evt-type %u, addr-type %u, addr %s, rssi %u, length adv %u, data: ", e->event_type,
           e->address_type, bd_addr_to_str(e->address), e->rssi, e->length);
    printf_hexdump(e->data, e->length);
    
}

static void dump_characteristic_value(uint8_t * blob, uint16_t blob_length){
    printf("    * characteristic value of length %d *** ", blob_length );
    printf_hexdump(blob , blob_length);
    printf("\n");
}

static void dump_characteristic(le_characteristic_t * characteristic){
    printf("    * characteristic: [0x%04x-0x%04x-0x%04x], properties 0x%02x, uuid ",
                            characteristic->start_handle, characteristic->value_handle, characteristic->end_handle, characteristic->properties);
    printUUID(characteristic->uuid128, characteristic->uuid16);
    printf("\n");
}

static void dump_service(le_service_t * service){
    printf("    * service: [0x%04x-0x%04x], uuid ", service->start_group_handle, service->end_group_handle);
    printUUID(service->uuid128, service->uuid16);
    printf("\n");
}

static void error_code(int status){
    switch(status){
        case ATT_ERROR_INSUFFICIENT_AUTHENTICATION: 
            printf("ATT_ERROR_INSUFFICIENT_AUTHENTICATION. TODO: security manager is not complete yet.\n");
            break;
        default:
            printf(" status 0x%02x\n", status);
            break;
    }
}

static void extract_service(le_service_t * service, uint8_t * packet){
    service->start_group_handle = READ_BT_16(packet, 4);
    service->end_group_handle   = READ_BT_16(packet, 6);
    service->uuid16 = 0;
    swap128(&packet[8], service->uuid128);
    if (sdp_has_blueooth_base_uuid(service->uuid128)){
        service->uuid16 = READ_NET_32(service->uuid128, 0);
    }
}

static void extract_characteristic(le_characteristic_t * characteristic, uint8_t * packet){
    characteristic->start_handle = READ_BT_16(packet, 4);
    characteristic->value_handle = READ_BT_16(packet, 6);
    characteristic->end_handle =   READ_BT_16(packet, 8);
    characteristic->properties =   READ_BT_16(packet, 10);
    characteristic->uuid16 = 0;
    swap128(&packet[12], characteristic->uuid128);
    if (sdp_has_blueooth_base_uuid(characteristic->uuid128)){
        characteristic->uuid16 = READ_NET_32(characteristic->uuid128, 0);
    }
}

static void handle_gatt_client_event(uint8_t packet_type, uint8_t *packet, uint16_t size){

    switch(state){
        case TC_W4_SERVICE_RESULT:
            switch(packet[0]){
                case GATT_SERVICE_QUERY_RESULT:
                    extract_service(&battery_service, packet);
                    printf("Battery service found:\n");
                    dump_service(&battery_service);
                    break;
                case GATT_QUERY_COMPLETE:
                    if (!packet[4]){
                        printf("Battery service not found. Restart scan.\n");
                        state = TC_W4_SCAN_RESULT;
                        le_central_start_scan();
                        break;  
                    } 
                    state = TC_W4_CHARACTERISTIC_RESULT;
                    printf("\nSearch for battery level characteristic in battery service. ");
                    gatt_client_discover_characteristics_for_service_by_uuid16(gc_id, gc_handle, &battery_service, battery_level_characteristic_uuid);
                    break;
                default:
                    break;
            }
            break;
            
        case TC_W4_CHARACTERISTIC_RESULT:
            switch(packet[0]){
                case GATT_CHARACTERISTIC_QUERY_RESULT:
                    printf("Battery level characteristic found:\n");
                    extract_characteristic(&config_characteristic, packet);
                    dump_characteristic(&config_characteristic);
                    break;
                case GATT_QUERY_COMPLETE:
                    state = TC_W4_BATTERY_DATA;
                    printf("\nConfigure battery level characteristic for notify.");
                    gatt_client_write_client_characteristic_configuration(gc_id, gc_handle, &config_characteristic, GATT_CLIENT_CHARACTERISTICS_CONFIGURATION_NOTIFICATION);
                    break;
                default:
                    break;
            }
            break;
        case TC_W4_BATTERY_DATA:
            if (packet[0] == GATT_QUERY_COMPLETE){
                if (packet[4] != 0){
                    printf("\nNotification is not possible: ");
                    error_code(packet[4]);
                }
                break;    
            }
            if (packet[0] != GATT_NOTIFICATION) break;
            printf("\nBattery Data:\n");
            dump_characteristic_value(&packet[8], READ_BT_16(packet, 6));
            break;

        default:
            printf("error\n");
            break;
    }
    
}

static void fill_advertising_report_from_packet(advertising_report_t * report, uint8_t *packet){
    int pos = 2;
    report->event_type = packet[pos++];
    report->address_type = packet[pos++];
    bt_flip_addr(report->address, &packet[pos]);
    pos += 6;
    report->rssi = packet[pos++];
    report->length = packet[pos++];
    report->data = &packet[pos];
    pos += report->length;
    dump_advertising_report(report);
}

static void handle_hci_event(void * connection, uint8_t packet_type, uint16_t channel, uint8_t *packet, uint16_t size){
    if (packet_type != HCI_EVENT_PACKET) return;
    advertising_report_t report;
    uint8_t event = packet[0];
    switch (event) {
        case BTSTACK_EVENT_STATE:
            // BTstack activated, get started
            if (packet[2] != HCI_STATE_WORKING) break;
            if (cmdline_addr_found){
                printf("Start connect to %s\n", bd_addr_to_str(cmdline_addr));
                state = TC_W4_CONNECT;
                le_central_connect(cmdline_addr, 0);
                break;
            }
            printf("BTstack activated, start scanning!\n");
            state = TC_W4_SCAN_RESULT;
            le_central_set_scan_parameters(0,0x0030, 0x0030);
            le_central_start_scan();
            break;
        case GAP_LE_ADVERTISING_REPORT:
            if (state != TC_W4_SCAN_RESULT) return;
            fill_advertising_report_from_packet(&report, packet);
            // stop scanning, and connect to the device
            state = TC_W4_CONNECT;
            le_central_stop_scan();
            printf("Stop scan. Start connect to device with addr %s.\n", bd_addr_to_str(report.address));
            le_central_connect(report.address,report.address_type);
            break;
        case HCI_EVENT_LE_META:
            // wait for connection complete
            if (packet[2] !=  HCI_SUBEVENT_LE_CONNECTION_COMPLETE) break;
            if (state != TC_W4_CONNECT) return;
            gc_handle = READ_BT_16(packet, 4);
            // initialize gatt client context with handle, and add it to the list of active clients
            // query primary services
            printf("\nSearch for battery service. ");
            state = TC_W4_SERVICE_RESULT;
            gatt_client_discover_primary_services_by_uuid16(gc_id, gc_handle, battery_service_uuid);
            break;
        case HCI_EVENT_DISCONNECTION_COMPLETE:
            printf("\nDISCONNECTED\n");
            exit(0);
            break;
        default:
            break;
    }
}

static void usage(const char *name){
	fprintf(stderr, "\nUsage: %s [-a|--address aa:bb:cc:dd:ee:ff]\n", name);
	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");
}

int btstack_main(int argc, const char * argv[]);
int btstack_main(int argc, const char * argv[]){

    int arg = 1;
    cmdline_addr_found = 0;
    
    while (arg < argc) {
		if(!strcmp(argv[arg], "-a") || !strcmp(argv[arg], "--address")){
			arg++;
			cmdline_addr_found = sscan_bd_addr((uint8_t *)argv[arg], cmdline_addr);
            arg++;
            continue;
        }
        usage(argv[0]);
        return 0;
	}

    l2cap_init();
    l2cap_register_packet_handler(&handle_hci_event);

    gatt_client_init();
    gc_id = gatt_client_register_packet_handler(&handle_gatt_client_event);

    sm_init();
    sm_set_io_capabilities(IO_CAPABILITY_NO_INPUT_NO_OUTPUT);

    // turn on!
    hci_power_control(HCI_POWER_ON);

    return 0;
}