/*
* 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
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* 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 BLUEKITCHEN
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* Please inquire about commercial licensing options at
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*/
#define BTSTACK_FILE__ "spp_flowcontrol.c"
// *****************************************************************************
/* EXAMPLE_START(spp_flowcontrol): SPP Server - RFCOMM Flow Control
*
* @text This example adds explicit flow control for incoming RFCOMM data to the
* SPP heartbeat counter example. We will highlight the changes compared to the
* SPP counter example.
*/
// *****************************************************************************
#include <stdint.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include "btstack.h"
#define HEARTBEAT_PERIOD_MS 500
#define TEST_COD 0x1234
#define RFCOMM_SERVER_CHANNEL 1
static void packet_handler (uint8_t packet_type, uint16_t channel, uint8_t *packet, uint16_t size);
static uint16_t rfcomm_channel_id;
static uint8_t rfcomm_send_credit = 0;
static uint8_t spp_service_buffer[150];
static btstack_packet_callback_registration_t hci_event_callback_registration;
/* @section SPP Service Setup
*
* @text Listing explicitFlowControl shows how to
* provide one initial credit during RFCOMM service initialization. Please note
* that providing a single credit effectively reduces the credit-based (sliding
* window) flow control to a stop-and-wait flow control that limits the data
* throughput substantially.
*/
/* LISTING_START(explicitFlowControl): Providing one initial credit during RFCOMM service initialization */
static void spp_service_setup(void){
// register for HCI events
hci_event_callback_registration.callback = &packet_handler;
hci_add_event_handler(&hci_event_callback_registration);
// init L2CAP
l2cap_init();
// init RFCOMM
rfcomm_init();
// reserved channel, mtu limited by l2cap, 1 credit
rfcomm_register_service_with_initial_credits(&packet_handler, RFCOMM_SERVER_CHANNEL, 0xffff, 1);
// init SDP, create record for SPP and register with SDP
sdp_init();
memset(spp_service_buffer, 0, sizeof(spp_service_buffer));
spp_create_sdp_record(spp_service_buffer, sdp_create_service_record_handle(), 1, "SPP Counter");
btstack_assert(de_get_len( spp_service_buffer) <= sizeof(spp_service_buffer));
sdp_register_service(spp_service_buffer);
}
/* LISTING_END */
/* @section Periodic Timer Setup
*
* @text Explicit credit management is
* recommended when received RFCOMM data cannot be processed immediately. In this
* example, delayed processing of received data is simulated with the help of a
* periodic timer as follows. When the packet handler receives a data packet, it
* does not provide a new credit, it sets a flag instead, see Listing phManual.
* If the flag is set, a new
* credit will be granted by the heartbeat handler, introducing a delay of up to 1
* second. The heartbeat handler code is shown in Listing hbhManual.
*/
static btstack_timer_source_t heartbeat;
/* LISTING_START(hbhManual): Heartbeat handler with manual credit management */
static void heartbeat_handler(struct btstack_timer_source *ts){
if (rfcomm_send_credit){
rfcomm_grant_credits(rfcomm_channel_id, 1);
rfcomm_send_credit = 0;
}
btstack_run_loop_set_timer(ts, HEARTBEAT_PERIOD_MS);
btstack_run_loop_add_timer(ts);
}
/* LISTING_END */
static void one_shot_timer_setup(void){
heartbeat.process = &heartbeat_handler;
btstack_run_loop_set_timer(&heartbeat, HEARTBEAT_PERIOD_MS);
btstack_run_loop_add_timer(&heartbeat);
}
/* LISTING_START(phManual): Packet handler with manual credit management */
// Bluetooth logic
static void packet_handler (uint8_t packet_type, uint16_t channel, uint8_t *packet, uint16_t size){
/* LISTING_PAUSE */
UNUSED(channel);
bd_addr_t event_addr;
uint8_t rfcomm_channel_nr;
uint16_t mtu;
int i;
switch (packet_type) {
case HCI_EVENT_PACKET:
switch (hci_event_packet_get_type(packet)) {
case HCI_EVENT_PIN_CODE_REQUEST:
// inform about pin code request
printf("Pin code request - using '0000'\n");
hci_event_pin_code_request_get_bd_addr(packet, event_addr);
gap_pin_code_response(event_addr, "0000");
break;
case RFCOMM_EVENT_INCOMING_CONNECTION:
rfcomm_event_incoming_connection_get_bd_addr(packet, event_addr);
rfcomm_channel_nr = rfcomm_event_incoming_connection_get_server_channel(packet);
rfcomm_channel_id = rfcomm_event_incoming_connection_get_rfcomm_cid(packet);
printf("RFCOMM channel %u requested for %s\n", rfcomm_channel_nr, bd_addr_to_str(event_addr));
rfcomm_accept_connection(rfcomm_channel_id);
break;
case RFCOMM_EVENT_CHANNEL_OPENED:
if (rfcomm_event_channel_opened_get_status(packet)) {
printf("RFCOMM channel open failed, status 0x%02x\n", rfcomm_event_channel_opened_get_status(packet));
} else {
rfcomm_channel_id = rfcomm_event_channel_opened_get_rfcomm_cid(packet);
mtu = rfcomm_event_channel_opened_get_max_frame_size(packet);
printf("RFCOMM channel open succeeded. New RFCOMM Channel ID 0x%02x, max frame size %u\n", rfcomm_channel_id, mtu);
}
break;
case RFCOMM_EVENT_CHANNEL_CLOSED:
rfcomm_channel_id = 0;
break;
default:
break;
}
break;
/* LISTING_RESUME */
case RFCOMM_DATA_PACKET:
for (i=0;i<size;i++){
putchar(packet[i]);
};
putchar('\n');
rfcomm_send_credit = 1;
break;
/* LISTING_PAUSE */
default:
break;
}
/* LISTING_RESUME */
}
/* LISTING_END */
int btstack_main(int argc, const char * argv[]);
int btstack_main(int argc, const char * argv[]){
(void)argc;
(void)argv;
l2cap_init();
#ifdef ENABLE_BLE
// Initialize LE Security Manager. Needed for cross-transport key derivation
sm_init();
#endif
spp_service_setup();
one_shot_timer_setup();
puts("SPP FlowControl Demo: simulates processing on received data...\n\r");
gap_set_local_name("SPP Flowcontrol 00:00:00:00:00:00");
gap_discoverable_control(1);
// short-cut to find other SPP Streamer
gap_set_class_of_device(TEST_COD);
// turn on!
hci_power_control(HCI_POWER_ON);
return 0;
}
/* EXAMPLE_END */