spp_camera.cpp

#if 1
// spp_camera.cpp
#include "mbed.h"
#include <btstack/hci_cmds.h>
#include <btstack/run_loop.h>
#include <btstack/sdp_util.h>

#include "hci.h"
#include "l2cap.h"
#include "btstack_memory.h"
#include "remote_device_db.h"
#include "rfcomm.h"
#include "sdp.h"
#include "config.h"
#include "debug.h"
#include "bd_addr.h"  // class bd_addr
#include "uvc.h"
#include <queue>
#include <string>

Serial pc(USBTX, USBRX);
DigitalOut led1(LED1), led2(LED2), led3(LED3), led4(LED4);

#define CAMERA_INTERVAL_MS 5000 

static uint8_t   rfcomm_channel_nr = 1;
static uint16_t  rfcomm_channel_id = 0;
static uint8_t   spp_service_buffer[128];

uvc* cam = NULL;
Timer cam_t;
queue<string> send_queue;

// Bluetooth logic
static void packet_handler(void * connection, uint8_t packet_type, uint16_t channel, uint8_t *packet, uint16_t size){
    bd_addr_t event_addr;
    uint8_t   rfcomm_channel_nr;
    uint16_t  mtu;
    
    switch (packet_type) {
        case HCI_EVENT_PACKET:
            switch (packet[0]) {
                    
                case BTSTACK_EVENT_STATE:
                    // bt stack activated, get started - set local name
                    if (packet[2] == HCI_STATE_WORKING) {
                        hci_send_cmd(&hci_write_local_name, "mbed");
                    }
                    break;
                
                case HCI_EVENT_COMMAND_COMPLETE:
                    if (COMMAND_COMPLETE_EVENT(packet, hci_read_bd_addr)){
                        bt_flip_addr(event_addr, &packet[6]);
                        log_info("BD-ADDR: %s\n\r", bd_addr_to_str(event_addr));
                        break;
                    }
                    if (COMMAND_COMPLETE_EVENT(packet, hci_write_local_name)){
                        hci_discoverable_control(1);
                        break;
                    }
                    break;

                case HCI_EVENT_LINK_KEY_REQUEST:
                    // deny link key request
                    log_info("Link key request\n\r");
                    bt_flip_addr(event_addr, &packet[2]);
                    hci_send_cmd(&hci_link_key_request_negative_reply, &event_addr);
                    break;
                    
                case HCI_EVENT_PIN_CODE_REQUEST:
                    // inform about pin code request
                    log_info("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 RFCOMM_EVENT_INCOMING_CONNECTION:
                    // data: event (8), len(8), address(48), channel (8), rfcomm_cid (16)
                    bt_flip_addr(event_addr, &packet[2]); 
                    rfcomm_channel_nr = packet[8];
                    rfcomm_channel_id = READ_BT_16(packet, 9);
                    log_info("RFCOMM channel %u requested for %s\n\r", rfcomm_channel_nr, bd_addr_to_str(event_addr));
                    rfcomm_accept_connection_internal(rfcomm_channel_id);
                    break;
                    
                case RFCOMM_EVENT_OPEN_CHANNEL_COMPLETE:
                    // data: event(8), len(8), status (8), address (48), server channel(8), rfcomm_cid(16), max frame size(16)
                    if (packet[2]) {
                        log_info("RFCOMM channel open failed, status %u\n\r", packet[2]);
                    } else {
                        rfcomm_channel_id = READ_BT_16(packet, 12);
                        mtu = READ_BT_16(packet, 14);
                        log_info("\n\rRFCOMM channel open succeeded. New RFCOMM Channel ID %u, max frame size %u\n\r", rfcomm_channel_id, mtu);
                    }
                    break;
                    
                case RFCOMM_EVENT_CHANNEL_CLOSED:
                    rfcomm_channel_id = 0;
                    break;
                
                default:
                    break;
            }
            break;
                        
        default:
            break;
    }
}

void cam_packet(uint8_t* buf, int len, int st = 0)
{
    //log_info("%d %d\n", st, len);
    string packet;
    for(int i = 0; i < len; i++) {
        char str[8];
        snprintf(str, sizeof(str), "%02X", buf[i]);
        packet += str;
    }
    packet += "\n";
    if (st == 2) {
        packet += "\n";
    }
    send_queue.push(packet);
}

void callback_motion_jpeg(uint16_t frame, uint8_t* buf, int len)
{
    static uint8_t bfh = 0x00;
    static int seq = 0;
    
    if (len <= 12) {
        return;
    }
    uint8_t* data = buf+12;
    int data_len = len - 12;
    switch(seq) {
        case 0:
            if (cam_t.read_ms() > CAMERA_INTERVAL_MS) {
                seq++;
            }
            break;
        case 1:
            if ((buf[1]^bfh)&0x01) { // FID change
                cam_packet(data, data_len, 1); 
                seq++;
            } else {
                break;
            }
        case 2:
            if (buf[1]&0x02) { // EOF
                cam_packet(data, data_len, 2); 
                seq = 0;
                cam_t.reset();
                led2 = !led2;
            } else {
                cam_packet(data, data_len, 0); 
            }
            break;
    }        
    bfh = buf[1];

    led1 = buf[1]&1; // FID
}

static int cam_process_ds(struct data_source *ds) {
    while(!send_queue.empty()) {
        string packet = send_queue.front();
        if (rfcomm_channel_id){
            int r = rfcomm_send_internal(rfcomm_channel_id, (uint8_t*)packet.data(), packet.size());
            if (r == RFCOMM_NO_OUTGOING_CREDITS) {
                break;
            }
            if (r) {
                log_info("rfcomm_send_internal -> error %d", r);
                send_queue.pop();
                break;
            }
            send_queue.pop();
            led3 = !led3;
        } else {
            send_queue.pop();
            break;
        }
    }
    if (cam) {
        cam->poll();
    }
    return 0;
}

// main
int main(void)
{
    pc.baud(921600);
    log_info("%s\n", __FILE__);


    // init LEDs
    led1 = led2 = led3 = led4 = 0;
    
    /// GET STARTED with BTstack ///
    btstack_memory_init();
    run_loop_init(RUN_LOOP_EMBEDDED);
    
    // init HCI
    hci_transport_t    * transport = hci_transport_usb_instance();
    remote_device_db_t * remote_db = (remote_device_db_t *) &remote_device_db_memory;
    hci_init(transport, NULL, NULL, remote_db);
    
    // init L2CAP
    l2cap_init();
    l2cap_register_packet_handler(packet_handler);
    
    // init RFCOMM
    rfcomm_init();
    rfcomm_register_packet_handler(packet_handler);
    rfcomm_register_service_internal(NULL, rfcomm_channel_nr, 100);  // reserved channel, mtu=100

    // init SDP, create record for SPP and register with SDP
    sdp_init();
    memset(spp_service_buffer, 0, sizeof(spp_service_buffer));
    service_record_item_t * service_record_item = (service_record_item_t *) spp_service_buffer;
    sdp_create_spp_service( (uint8_t*) &service_record_item->service_record, 1, "camera");
    log_info("SDP service buffer size: %u\n", (uint16_t) (sizeof(service_record_item_t) + de_get_len((uint8_t*) &service_record_item->service_record)));
    sdp_register_service_internal(NULL, service_record_item);
    

    // init camera
    cam = new uvc;
    cam->SetImageSize(160, 120);
    cam->setOnResult(callback_motion_jpeg);
    if (cam->setup()< 0){printf("cam setup error\n");exit(1);}
    cam_t.reset();
    cam_t.start();
    
    data_source_t *ds = (data_source_t*)malloc(sizeof(data_source_t));
    ds->process = cam_process_ds;
    run_loop_add_data_source(ds);

    log_info("Run...\n\r");

     // turn on!
    hci_power_control(HCI_POWER_ON);

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

#endif