/*
* 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
*
*/
#define __BTSTACK_FILE__ "le_streamer.c"
// *****************************************************************************
/* EXAMPLE_START(le_streamer): LE Peripheral - Stream data over GATT
*
* @text All newer operating systems provide GATT Client functionality.
* This example shows how to get a maximal throughput via BLE:
* - send whenever possible
* - use the max ATT MTU
*
* In theory, we should also update the connection parameters, but we already get
* a connection interval of 30 ms and there's no public way to use a shorter
* interval with iOS (if we're not implementing an HID device)
*/
// *****************************************************************************
#include <stdint.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include "btstack.h"
#include "le_streamer.h"
static int le_notification_enabled;
static void packet_handler (uint8_t packet_type, uint16_t channel, uint8_t *packet, uint16_t size);
static int att_write_callback(hci_con_handle_t con_handle, uint16_t att_handle, uint16_t transaction_mode, uint16_t offset, uint8_t *buffer, uint16_t buffer_size);
static void streamer(void);
static btstack_packet_callback_registration_t hci_event_callback_registration;
const uint8_t adv_data[] = {
// Flags general discoverable, BR/EDR not supported
0x02, 0x01, 0x06,
// Name
0x0c, 0x09, 'L', 'E', ' ', 'S', 't', 'r', 'e', 'a', 'm', 'e', 'r',
};
const uint8_t adv_data_len = sizeof(adv_data);
static int counter = 'A';
static char test_data[200];
static int test_data_len;
static hci_con_handle_t connection_handle;
/* @section Main Application Setup
*
* @text Listing MainConfiguration shows main application code.
* It initializes L2CAP, the Security Manager, and configures the ATT Server with the pre-compiled
* ATT Database generated from $le_streamer.gatt$. Finally, it configures the advertisements
* and boots the Bluetooth stack.
*/
/* LISTING_START(MainConfiguration): Init L2CAP, SM, ATT Server, and enable advertisements */
static void le_streamer_setup(void){
// register for HCI events
hci_event_callback_registration.callback = &packet_handler;
hci_add_event_handler(&hci_event_callback_registration);
l2cap_init();
// setup le device db
le_device_db_init();
// setup SM: Display only
sm_init();
// setup ATT server
att_server_init(profile_data, NULL, att_write_callback);
att_server_register_packet_handler(packet_handler);
// setup advertisements
uint16_t adv_int_min = 0x0030;
uint16_t adv_int_max = 0x0030;
uint8_t adv_type = 0;
bd_addr_t null_addr;
memset(null_addr, 0, 6);
gap_advertisements_set_params(adv_int_min, adv_int_max, adv_type, 0, null_addr, 0x07, 0x00);
gap_advertisements_set_data(adv_data_len, (uint8_t*) adv_data);
gap_advertisements_enable(1);
}
/* LISTING_END */
/*
* @section Track throughput
* @text We calculate the throughput by setting a start time and measuring the amount of
* data sent. After a configurable REPORT_INTERVAL_MS, we print the throughput in kB/s
* and reset the counter and start time.
*/
/* LISTING_START(tracking): Tracking throughput */
#define REPORT_INTERVAL_MS 3000
static uint32_t test_data_sent;
static uint32_t test_data_start;
static void test_reset(void){
test_data_start = btstack_run_loop_get_time_ms();
test_data_sent = 0;
}
static void test_track_sent(int bytes_sent){
test_data_sent += bytes_sent;
// evaluate
uint32_t now = btstack_run_loop_get_time_ms();
uint32_t time_passed = now - test_data_start;
if (time_passed < REPORT_INTERVAL_MS) return;
// print speed
int bytes_per_second = test_data_sent * 1000 / time_passed;
printf("%u bytes sent-> %u.%03u kB/s\n", test_data_sent, bytes_per_second / 1000, bytes_per_second % 1000);
// restart
test_data_start = now;
test_data_sent = 0;
}
/* LISTING_END(tracking): Tracking throughput */
/*
* @section Packet Handler
*
* @text The packet handler is used to stop the notifications and reset the MTU on connect
* It would also be a good place to request the connection parameter update as indicated
* in the commented code block.
*/
/* LISTING_START(packetHandler): Packet Handler */
static void packet_handler (uint8_t packet_type, uint16_t channel, uint8_t *packet, uint16_t size){
UNUSED(channel);
UNUSED(size);
int mtu;
switch (packet_type) {
case HCI_EVENT_PACKET:
switch (hci_event_packet_get_type(packet)) {
case HCI_EVENT_DISCONNECTION_COMPLETE:
le_notification_enabled = 0;
break;
case HCI_EVENT_LE_META:
switch (hci_event_le_meta_get_subevent_code(packet)) {
case HCI_SUBEVENT_LE_CONNECTION_COMPLETE:
test_data_len = ATT_DEFAULT_MTU - 3;
connection_handle = hci_subevent_le_connection_complete_get_connection_handle(packet);
// min con interval 20 ms
// gap_request_connection_parameter_update(connection_handle, 0x10, 0x18, 0, 0x0048);
// printf("Connected, requesting conn param update for handle 0x%04x\n", connection_handle);
break;
}
break;
case ATT_EVENT_MTU_EXCHANGE_COMPLETE:
mtu = att_event_mtu_exchange_complete_get_MTU(packet) - 3;
mtu = 27;
printf("ATT MTU = %u\n", mtu);
test_data_len = mtu - 3;
if (test_data_len > sizeof(test_data)){
test_data_len = sizeof(test_data);
}
break;
case ATT_EVENT_CAN_SEND_NOW:
streamer();
break;
}
}
}
/* LISTING_END */
/*
* @section Streamer
*
* @text The streamer function checks if notifications are enabled and if a notification can be sent now.
* It creates some test data - a single letter that gets increased every time - and tracks the data sent.
*/
/* LISTING_START(streamer): Streaming code */
static void streamer(void){
// check if we can send
if (!le_notification_enabled) return;
// create test data
counter++;
if (counter > 'Z') counter = 'A';
memset(test_data, counter, sizeof(test_data));
// send
att_server_notify(connection_handle, ATT_CHARACTERISTIC_0000FF11_0000_1000_8000_00805F9B34FB_01_VALUE_HANDLE, (uint8_t*) test_data, test_data_len);
// track
test_track_sent(test_data_len);
// request next send event
att_server_request_can_send_now_event(connection_handle);
}
/* LISTING_END */
/*
* @section ATT Write
*
* @text The only valid ATT write in this example is to the Client Characteristic Configuration, which configures notification
* and indication. If the ATT handle matches the client configuration handle, the new configuration value is stored.
* If notifications get enabled, an ATT_EVENT_CAN_SEND_NOW is requested. See Listing attWrite.
*/
/* LISTING_START(attWrite): ATT Write */
static int att_write_callback(hci_con_handle_t con_handle, uint16_t att_handle, uint16_t transaction_mode, uint16_t offset, uint8_t *buffer, uint16_t buffer_size){
UNUSED(con_handle);
UNUSED(offset);
// printf("att_write_callback att_handle %04x, transaction mode %u\n", att_handle, transaction_mode);
if (transaction_mode != ATT_TRANSACTION_MODE_NONE) return 0;
switch(att_handle){
case ATT_CHARACTERISTIC_0000FF11_0000_1000_8000_00805F9B34FB_01_CLIENT_CONFIGURATION_HANDLE:
le_notification_enabled = little_endian_read_16(buffer, 0) == GATT_CLIENT_CHARACTERISTICS_CONFIGURATION_NOTIFICATION;
printf("Notifications enabled %u\n", le_notification_enabled);
if (le_notification_enabled){
att_server_request_can_send_now_event(connection_handle);
}
test_reset();
break;
case ATT_CHARACTERISTIC_0000FF12_0000_1000_8000_00805F9B34FB_01_VALUE_HANDLE:
printf("Write to ...FF12...: ");
printf_hexdump(buffer, buffer_size);
break;
}
return 0;
}
/* LISTING_END */
int btstack_main(void);
int btstack_main(void)
{
le_streamer_setup();
// turn on!
hci_power_control(HCI_POWER_ON);
return 0;
}
/* EXAMPLE_END */