btstack/example/embedded/hsp_test.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
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 * 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
 *
 */
 
// *****************************************************************************
//
// Minimal setup for HSP Audio Gateway
//
// *****************************************************************************

#include "btstack-config.h"

#include <stdint.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>


#include <btstack/hci_cmds.h>
#include <btstack/run_loop.h>

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

static bd_addr_t remote = {0x00, 0x21, 0x3C, 0xAC, 0xF7, 0x38};
static uint8_t channel_nr = 0;

static uint16_t mtu;
static uint16_t rfcomm_cid = 0;

static uint8_t connection_state = 0;

// remote audio volume control
static void hsp_set_microphone_gain(){}; // +VGM=13 [0..15]
static void hsp_set_speaker_gain(){};    // +VGS=5  [0..15]

static void send_str_over_rfcomm(uint16_t cid, char * command){
    printf("Send %s.\n", command);
    int err = rfcomm_send_internal(cid, (uint8_t*) command, strlen(command));
    if (err){
        printf("rfcomm_send_internal -> error 0X%02x", err);
    }
}

static void send_packet(){
    switch (connection_state){
        case 1:
            send_str_over_rfcomm(rfcomm_cid, "\r\nRING\r\n");
            connection_state++;
            break;
        case 3:
            send_str_over_rfcomm(rfcomm_cid, "\r\nOK\r\n");
            connection_state++;
            break;
        default:
            break;
    }
}


static void packet_handler (void * connection, uint8_t packet_type, uint16_t channel, uint8_t *packet, uint16_t size){
    // printf("packet_handler type %u, packet[0] %x\n", packet_type, packet[0]);
    if (packet_type == RFCOMM_DATA_PACKET){
        if (strncmp((char *)packet, "AT+CKPD", 7) == 0){
            printf("Received AT+CKPD\n");
            connection_state++;
            if (rfcomm_can_send_packet_now(rfcomm_cid)) send_packet();
        }
        return;   
    }

    if (packet_type != HCI_EVENT_PACKET) return;
    uint8_t event = packet[0];
    bd_addr_t event_addr;
    uint16_t handle;

    switch (event) {
        case BTSTACK_EVENT_STATE:
            // bt stack activated, get started 
            if (packet[2] == HCI_STATE_WORKING){
                printf("Start SDP RFCOMM Query for UUID 0x%02x\n", SDP_HSP);
                sdp_query_rfcomm_channel_and_name_for_uuid(remote, SDP_HSP);
            }
            break;

        case HCI_EVENT_PIN_CODE_REQUEST:
            // inform about pin code request
            printf("Pin code request - using '0000'\n\r");
            bt_flip_addr(event_addr, &packet[2]);
            hci_send_cmd(&hci_pin_code_request_reply, &event_addr, 4, "0000");
            break;

        case HCI_EVENT_SYNCHRONOUS_CONNECTION_COMPLETE:{
            int index = 2;
            uint8_t status = packet[index++];
            uint16_t connection_handle = READ_BT_16(packet, index);
            index+=2;
            bd_addr_t address; 
            memcpy(address, &packet[index], 6);
            index+=6;
            uint8_t link_type = packet[index++];
            uint8_t transmission_interval = packet[index++];  // measured in slots
            uint8_t retransmission_interval = packet[index++];// measured in slots
            uint16_t rx_packet_length = READ_BT_16(packet, index); // measured in bytes
            index+=2;
            uint16_t tx_packet_length = READ_BT_16(packet, index); // measured in bytes
            index+=2;
            uint8_t air_mode = packet[index];

            if (status != 0){
                log_error("(e)SCO Connection is not established, status %u", status);
                exit(0);
                break;
            }
            switch (link_type){
                case 0x00:
                    printf("SCO Connection established. \n");
                    if (transmission_interval != 0) log_error("SCO Connection: transmission_interval not zero: %d.", transmission_interval);
                    if (retransmission_interval != 0) log_error("SCO Connection: retransmission_interval not zero: %d.", retransmission_interval);
                    if (rx_packet_length != 0) log_error("SCO Connection: rx_packet_length not zero: %d.", rx_packet_length);
                    if (tx_packet_length != 0) log_error("SCO Connection: tx_packet_length not zero: %d.", tx_packet_length);
                    break;
                case 0x02:
                    printf("eSCO Connection established. \n");
                    break;
                default:
                    log_error("(e)SCO reserved link_type 0x%2x", link_type);
                    break;
            }
            log_info("connection_handle 0x%2x, address %s, transmission_interval %u slots, retransmission_interval %u slots, " 
                 " rx_packet_length %u bytes, tx_packet_length %u bytes, air_mode 0x%2x (0x02 == CVSD)", connection_handle,
                 bd_addr_to_str(address), transmission_interval, retransmission_interval, rx_packet_length, tx_packet_length, air_mode);

            // Send "RING"
            connection_state++;
            if (rfcomm_can_send_packet_now(rfcomm_cid)) send_packet();
            break;                
        }

        case RFCOMM_EVENT_OPEN_CHANNEL_COMPLETE:
            printf("RFCOMM_EVENT_OPEN_CHANNEL_COMPLETE packet_handler type %u, packet[0] %x\n", packet_type, packet[0]);
            // data: event(8), len(8), status (8), address (48), handle(16), server channel(8), rfcomm_cid(16), max frame size(16)
            if (packet[2]) {
                printf("RFCOMM channel open failed, status %u\n", packet[2]);
            } else {
                // data: event(8) , len(8), status (8), address (48), handle (16), server channel(8), rfcomm_cid(16), max frame size(16)
                handle = READ_BT_16(packet, 9);
                rfcomm_cid = READ_BT_16(packet, 12);
                mtu = READ_BT_16(packet, 14);
                printf("RFCOMM channel open succeeded. New RFCOMM Channel ID %u, max frame size %u\n", rfcomm_cid, mtu);
                hci_send_cmd(&hci_setup_synchronous_connection_command, handle, 8000, 8000, 0xFFFF, 0x0060, 0xFF, 0x003F);
                /** 
                 * @param handle
                 * @param transmit_bandwidth = 8000 (64kbps)
                 * @param receive_bandwidth = 8000 (64kbps)
                 * @param max_latency >= 7ms for eSCO, 0xFFFF do not care
                 * @param voice_settings = CVSD, Input Coding: Linear, Input Data Format: 2’s complement, data 16bit: 00011000000 == 0x60
                 * @param retransmission_effort = 0xFF do not care
                 * @param packet_type = at least EV3 for eSCO; here we have 0x3F = {HV1-3, EV3-5}
                 */
                break;
            }
            break;
        case DAEMON_EVENT_HCI_PACKET_SENT:
        case RFCOMM_EVENT_CREDITS:
            if (!rfcomm_cid) break;
            if (rfcomm_can_send_packet_now(rfcomm_cid)) send_packet();
            break;
        default:
            break;
    }
}

void handle_query_rfcomm_event(sdp_query_event_t * event, void * context){
    sdp_query_rfcomm_service_event_t * ve;
    sdp_query_complete_event_t * ce;
            
    switch (event->type){
        case SDP_QUERY_RFCOMM_SERVICE:
            ve = (sdp_query_rfcomm_service_event_t*) event;
            channel_nr = ve->channel_nr;
            printf("** Service name: '%s', RFCOMM port %u\n", ve->service_name, channel_nr);
            break;
        case SDP_QUERY_COMPLETE:
            ce = (sdp_query_complete_event_t*) event;
            
            if (channel_nr > 0) {
                printf("RFCOMM create channel.\n");
                rfcomm_create_channel_internal(NULL, &remote, channel_nr); 
                break;
            }
            printf("Service not found.\n");
            exit(0);
            break;
    }
}

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

    printf("Client HCI init done\r\n");
        
    // init L2CAP
    l2cap_init();
    l2cap_register_packet_handler(packet_handler);
    rfcomm_init();
    rfcomm_register_packet_handler(packet_handler);

    sdp_query_rfcomm_register_callback(handle_query_rfcomm_event, NULL);

    // turn on!
    hci_power_control(HCI_POWER_ON);

    // go!
    run_loop_execute(); 
    return 0;
}