xref: /btstack/example/hid_keyboard_demo.c (revision 7ea7688a8f341f3783e40a238546a118134c6d1b)

/*
 * 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
 * [email protected]
 *
 */

#define __BTSTACK_FILE__ "hid_device_demo.c"

// *****************************************************************************
/* EXAMPLE_START(hid_device_demo): HID Device (Server) Demo
 *
 * Status: Basic implementation. HID Request from Host are not answered yet. Works with iOS.
 *
 * @text This HID Device example demonstrates how to implement
 * an HID keyboard. Without a HAVE_BTSTACK_STDIN, a fixed demo text is sent
 * If HAVE_BTSTACK_STDIN is defined, you can type from the terminal
 */
// *****************************************************************************


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

#include "btstack.h"

#ifdef HAVE_BTSTACK_STDIN
#include "btstack_stdin.h"
#endif

// to enable demo text on POSIX systems
// #undef HAVE_BTSTACK_STDIN

static uint8_t hid_service_buffer[250];
static const char hid_device_name[] = "BTstack HID Keyboard";
static btstack_packet_callback_registration_t hci_event_callback_registration;
static uint16_t hid_cid;

// from USB HID Specification 1.1, Appendix B.1
const uint8_t hid_descriptor_keyboard_boot_mode[] = {

    0x05, 0x01,                    // Usage Page (Generic Desktop)
    0x09, 0x06,                    // Usage (Keyboard)
    0xa1, 0x01,                    // Collection (Application)

    // Modifier byte

    0x75, 0x01,                    //   Report Size (1)
    0x95, 0x08,                    //   Report Count (8)
    0x05, 0x07,                    //   Usage Page (Key codes)
    0x19, 0xe0,                    //   Usage Minimum (Keyboard LeftControl)
    0x29, 0xe7,                    //   Usage Maxium (Keyboard Right GUI)
    0x15, 0x00,                    //   Logical Minimum (0)
    0x25, 0x01,                    //   Logical Maximum (1)
    0x81, 0x02,                    //   Input (Data, Variable, Absolute)

    // Reserved byte

    0x75, 0x01,                    //   Report Size (1)
    0x95, 0x08,                    //   Report Count (8)
    0x81, 0x03,                    //   Input (Constant, Variable, Absolute)

    // LED report + padding

    0x95, 0x05,                    //   Report Count (5)
    0x75, 0x01,                    //   Report Size (1)
    0x05, 0x08,                    //   Usage Page (LEDs)
    0x19, 0x01,                    //   Usage Minimum (Num Lock)
    0x29, 0x05,                    //   Usage Maxium (Kana)
    0x91, 0x02,                    //   Output (Data, Variable, Absolute)

    0x95, 0x01,                    //   Report Count (1)
    0x75, 0x03,                    //   Report Size (3)
    0x91, 0x03,                    //   Output (Constant, Variable, Absolute)

    // Keycodes

    0x95, 0x06,                    //   Report Count (6)
    0x75, 0x08,                    //   Report Size (8)
    0x15, 0x00,                    //   Logical Minimum (0)
    0x25, 0xff,                    //   Logical Maximum (1)
    0x05, 0x07,                    //   Usage Page (Key codes)
    0x19, 0x00,                    //   Usage Minimum (Reserved (no event indicated))
    0x29, 0xff,                    //   Usage Maxium (Reserved)
    0x81, 0x00,                    //   Input (Data, Array)

    0xc0,                          // End collection
};

//
#define CHAR_ILLEGAL     0xff
#define CHAR_RETURN     '\n'
#define CHAR_ESCAPE      27
#define CHAR_TAB         '\t'
#define CHAR_BACKSPACE   0x7f

// Simplified US Keyboard with Shift modifier

/**
 * English (US)
 */
static const uint8_t keytable_us_none [] = {
    CHAR_ILLEGAL, CHAR_ILLEGAL, CHAR_ILLEGAL, CHAR_ILLEGAL,             /*   0-3 */
    'a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', 'i', 'j',                   /*  4-13 */
    'k', 'l', 'm', 'n', 'o', 'p', 'q', 'r', 's', 't',                   /* 14-23 */
    'u', 'v', 'w', 'x', 'y', 'z',                                       /* 24-29 */
    '1', '2', '3', '4', '5', '6', '7', '8', '9', '0',                   /* 30-39 */
    CHAR_RETURN, CHAR_ESCAPE, CHAR_BACKSPACE, CHAR_TAB, ' ',            /* 40-44 */
    '-', '=', '[', ']', '\\', CHAR_ILLEGAL, ';', '\'', 0x60, ',',       /* 45-54 */
    '.', '/', CHAR_ILLEGAL, CHAR_ILLEGAL, CHAR_ILLEGAL, CHAR_ILLEGAL,   /* 55-60 */
    CHAR_ILLEGAL, CHAR_ILLEGAL, CHAR_ILLEGAL, CHAR_ILLEGAL,             /* 61-64 */
    CHAR_ILLEGAL, CHAR_ILLEGAL, CHAR_ILLEGAL, CHAR_ILLEGAL,             /* 65-68 */
    CHAR_ILLEGAL, CHAR_ILLEGAL, CHAR_ILLEGAL, CHAR_ILLEGAL,             /* 69-72 */
    CHAR_ILLEGAL, CHAR_ILLEGAL, CHAR_ILLEGAL, CHAR_ILLEGAL,             /* 73-76 */
    CHAR_ILLEGAL, CHAR_ILLEGAL, CHAR_ILLEGAL, CHAR_ILLEGAL,             /* 77-80 */
    CHAR_ILLEGAL, CHAR_ILLEGAL, CHAR_ILLEGAL, CHAR_ILLEGAL,             /* 81-84 */
    '*', '-', '+', '\n', '1', '2', '3', '4', '5',                       /* 85-97 */
    '6', '7', '8', '9', '0', '.', 0xa7,                                 /* 97-100 */
};

static const uint8_t keytable_us_shift[] = {
    CHAR_ILLEGAL, CHAR_ILLEGAL, CHAR_ILLEGAL, CHAR_ILLEGAL,             /*  0-3  */
    'A', 'B', 'C', 'D', 'E', 'F', 'G', 'H', 'I', 'J',                   /*  4-13 */
    'K', 'L', 'M', 'N', 'O', 'P', 'Q', 'R', 'S', 'T',                   /* 14-23 */
    'U', 'V', 'W', 'X', 'Y', 'Z',                                       /* 24-29 */
    '!', '@', '#', '$', '%', '^', '&', '*', '(', ')',                   /* 30-39 */
    CHAR_RETURN, CHAR_ESCAPE, CHAR_BACKSPACE, CHAR_TAB, ' ',            /* 40-44 */
    '_', '+', '{', '}', '|', CHAR_ILLEGAL, ':', '"', 0x7E, '<',         /* 45-54 */
    '>', '?', CHAR_ILLEGAL, CHAR_ILLEGAL, CHAR_ILLEGAL, CHAR_ILLEGAL,   /* 55-60 */
    CHAR_ILLEGAL, CHAR_ILLEGAL, CHAR_ILLEGAL, CHAR_ILLEGAL,             /* 61-64 */
    CHAR_ILLEGAL, CHAR_ILLEGAL, CHAR_ILLEGAL, CHAR_ILLEGAL,             /* 65-68 */
    CHAR_ILLEGAL, CHAR_ILLEGAL, CHAR_ILLEGAL, CHAR_ILLEGAL,             /* 69-72 */
    CHAR_ILLEGAL, CHAR_ILLEGAL, CHAR_ILLEGAL, CHAR_ILLEGAL,             /* 73-76 */
    CHAR_ILLEGAL, CHAR_ILLEGAL, CHAR_ILLEGAL, CHAR_ILLEGAL,             /* 77-80 */
    CHAR_ILLEGAL, CHAR_ILLEGAL, CHAR_ILLEGAL, CHAR_ILLEGAL,             /* 81-84 */
    '*', '-', '+', '\n', '1', '2', '3', '4', '5',                       /* 85-97 */
    '6', '7', '8', '9', '0', '.', 0xb1,                                 /* 97-100 */
};

// HID Keyboard lookup
static int lookup_keycode(uint8_t character, const uint8_t * table, int size, uint8_t * keycode){
    int i;
    for (i=0;i<size;i++){
        if (table[i] != character) continue;
        *keycode = i;
        return 1;
    }
    return 0;
}

static int keycode_and_modifer_us_for_character(uint8_t character, uint8_t * keycode, uint8_t * modifier){
    int found;
    found = lookup_keycode(character, keytable_us_none, sizeof(keytable_us_none), keycode);
    if (found) {
        *modifier = 0;  // none
        return 1;
    }
    found = lookup_keycode(character, keytable_us_shift, sizeof(keytable_us_shift), keycode);
    if (found) {
        *modifier = 2;  // shift
        return 1;
    }
    return 0;
}

// HID Report sending
static int send_keycode;
static int send_modifier;

static void send_key(int modifier, int keycode){
    send_keycode = keycode;
    send_modifier = modifier;
    hid_device_request_can_send_now_event(hid_cid);
}

static void send_report(int modifier, int keycode){
    uint8_t report[] = { 0xa1, modifier, 0, 0, keycode, 0, 0, 0, 0, 0};
    hid_device_send_interrupt_message(hid_cid, &report[0], sizeof(report));
}

// Demo Application

#ifdef HAVE_BTSTACK_STDIN

// On systems with STDIN, we can directly type on the console

static void stdin_process(btstack_data_source_t *ds, btstack_data_source_callback_type_t callback_type){
    UNUSED(ds);
    UNUSED(callback_type);

    char character = btstack_stdin_read();

    uint8_t modifier;
    uint8_t keycode;
    int found = keycode_and_modifer_us_for_character(character, &keycode, &modifier);
    if (found){
        send_key(modifier, keycode);
        return;
    }
}
#else

// On embedded systems, send constant demo text with fixed period

#define TYPING_PERIOD_MS 100
static const char * demo_text = "\n\nHello World!\n\nThis is the BTstack HID Keyboard Demo running on an Embedded Device.\n\n";

static int demo_pos;
static btstack_timer_source_t typing_timer;

static void typing_timer_handler(btstack_timer_source_t * ts){

    // abort if not connected
    if (!hid_cid) return;

    // get next character
    uint8_t character = demo_text[demo_pos++];
    if (demo_text[demo_pos] == 0){
        demo_pos = 0;
    }

    // get keycodeand send
    uint8_t modifier;
    uint8_t keycode;
    int found = keycode_and_modifer_us_for_character(character, &keycode, &modifier);
    if (found){
        send_key(modifier, keycode);
    }

    // set next timer
    btstack_run_loop_set_timer(ts, TYPING_PERIOD_MS);
    btstack_run_loop_add_timer(ts);
}

static void hid_embedded_start_typing(void){
    demo_pos = 0;
    // set one-shot timer
    typing_timer.process = &typing_timer_handler;
    btstack_run_loop_set_timer(&typing_timer, TYPING_PERIOD_MS);
    btstack_run_loop_add_timer(&typing_timer);
}

#endif

static void packet_handler(uint8_t packet_type, uint16_t channel, uint8_t * packet, uint16_t packet_size){
    UNUSED(channel);
    UNUSED(packet_size);
    switch (packet_type){
        case HCI_EVENT_PACKET:
            switch (packet[0]){
                case HCI_EVENT_USER_CONFIRMATION_REQUEST:
                    // ssp: inform about user confirmation request
                    log_info("SSP User Confirmation Request with numeric value '%06"PRIu32"'\n", hci_event_user_confirmation_request_get_numeric_value(packet));
                    log_info("SSP User Confirmation Auto accept\n");
                    break;

                case HCI_EVENT_HID_META:
                    switch (hci_event_hid_meta_get_subevent_code(packet)){
                        case HID_SUBEVENT_CONNECTION_OPENED:
                            if (hid_subevent_connection_opened_get_status(packet)) return;
                            hid_cid = hid_subevent_connection_opened_get_hid_cid(packet);
#ifdef HAVE_BTSTACK_STDIN
                            printf("HID Connected, please start typing...\n");
#else
                            printf("HID Connected, sending demo text...\n");
                            hid_embedded_start_typing();
#endif
                            break;
                        case HID_SUBEVENT_CONNECTION_CLOSED:
                            printf("HID Disconnected\n");
                            hid_cid = 0;
                            break;
                        case HID_SUBEVENT_CAN_SEND_NOW:
                            if (send_keycode){
                                send_report(send_modifier, send_keycode);
                                send_keycode = 0;
                                send_modifier = 0;
                                hid_device_request_can_send_now_event(hid_cid);
                            } else {
                                send_report(0, 0);
                            }
                            break;
                        default:
                            break;
                    }
                    break;
                default:
                    break;
            }
            break;
        default:
            break;
    }
}

/* @section Main Application Setup
 *
 * @text Listing MainConfiguration shows main application code.
 * To run a HID Device service you need to initialize the SDP, and to create and register HID Device record with it.
 * At the end the Bluetooth stack is started.
 */

/* LISTING_START(MainConfiguration): Setup HID Device */

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

    // register for HCI events
    hci_event_callback_registration.callback = &packet_handler;
    hci_add_event_handler(&hci_event_callback_registration);
    hci_register_sco_packet_handler(&packet_handler);

    gap_discoverable_control(1);
    gap_set_class_of_device(0x2540);
    gap_set_local_name(hid_device_name);

    // L2CAP
    l2cap_init();

    // SDP Server
    sdp_init();
    memset(hid_service_buffer, 0, sizeof(hid_service_buffer));
    // hid sevice subclass 2540 Keyboard, hid counntry code 33 US, hid virtual cable off, hid reconnect initiate off, hid boot device off
    hid_create_sdp_record(hid_service_buffer, 0x10001, 0x2540, 33, 0, 0, 0, hid_descriptor_keyboard_boot_mode, sizeof(hid_descriptor_keyboard_boot_mode), hid_device_name);
    printf("SDP service record size: %u\n", de_get_len( hid_service_buffer));
    sdp_register_service(hid_service_buffer);

    // HID Device
    hid_device_init();
    hid_device_register_packet_handler(&packet_handler);

#ifdef HAVE_BTSTACK_STDIN
    btstack_stdin_setup(stdin_process);
#endif
    // turn on!
    hci_power_control(HCI_POWER_ON);
    return 0;
}
/* LISTING_END */
/* EXAMPLE_END */