xref: /btstack/example/hid_keyboard_demo.c (revision 47f34e0cffc2da3ae0dfdf6cba95f7f9d992eb2f)
1 /*
2  * Copyright (C) 2014 BlueKitchen GmbH
3  *
4  * Redistribution and use in source and binary forms, with or without
5  * modification, are permitted provided that the following conditions
6  * are met:
7  *
8  * 1. Redistributions of source code must retain the above copyright
9  *    notice, this list of conditions and the following disclaimer.
10  * 2. Redistributions in binary form must reproduce the above copyright
11  *    notice, this list of conditions and the following disclaimer in the
12  *    documentation and/or other materials provided with the distribution.
13  * 3. Neither the name of the copyright holders nor the names of
14  *    contributors may be used to endorse or promote products derived
15  *    from this software without specific prior written permission.
16  * 4. Any redistribution, use, or modification is done solely for
17  *    personal benefit and not for any commercial purpose or for
18  *    monetary gain.
19  *
20  * THIS SOFTWARE IS PROVIDED BY BLUEKITCHEN GMBH AND CONTRIBUTORS
21  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
22  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
23  * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL BLUEKITCHEN
24  * GMBH OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
25  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
26  * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
27  * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
28  * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
29  * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF
30  * THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
31  * SUCH DAMAGE.
32  *
33  * Please inquire about commercial licensing options at
34  * [email protected]
35  *
36  */
37 
38 #define BTSTACK_FILE__ "hid_keyboard_demo.c"
39 
40 // *****************************************************************************
41 /* EXAMPLE_START(hid_keyboard_demo): HID Keyboard Classic
42  *
43  * @text This HID Device example demonstrates how to implement
44  * an HID keyboard. Without a HAVE_BTSTACK_STDIN, a fixed demo text is sent
45  * If HAVE_BTSTACK_STDIN is defined, you can type from the terminal
46  */
47 // *****************************************************************************
48 
49 
50 #include <stdint.h>
51 #include <stdio.h>
52 #include <stdlib.h>
53 #include <string.h>
54 #include <inttypes.h>
55 
56 #include "btstack.h"
57 
58 #ifdef HAVE_BTSTACK_STDIN
59 #include "btstack_stdin.h"
60 #endif
61 
62 // to enable demo text on POSIX systems
63 // #undef HAVE_BTSTACK_STDIN
64 
65 // timing of keypresses
66 #define TYPING_KEYDOWN_MS  20
67 #define TYPING_DELAY_MS    20
68 
69 // When not set to 0xffff, sniff and sniff subrating are enabled
70 static uint16_t host_max_latency = 1600;
71 static uint16_t host_min_timeout = 3200;
72 
73 #define REPORT_ID 0x01
74 
75 // close to USB HID Specification 1.1, Appendix B.1
76 const uint8_t hid_descriptor_keyboard[] = {
77 
78     0x05, 0x01,                    // Usage Page (Generic Desktop)
79     0x09, 0x06,                    // Usage (Keyboard)
80     0xa1, 0x01,                    // Collection (Application)
81 
82     // Report ID
83 
84     0x85, REPORT_ID,               // Report ID
85 
86     // Modifier byte (input)
87 
88     0x75, 0x01,                    //   Report Size (1)
89     0x95, 0x08,                    //   Report Count (8)
90     0x05, 0x07,                    //   Usage Page (Key codes)
91     0x19, 0xe0,                    //   Usage Minimum (Keyboard LeftControl)
92     0x29, 0xe7,                    //   Usage Maximum (Keyboard Right GUI)
93     0x15, 0x00,                    //   Logical Minimum (0)
94     0x25, 0x01,                    //   Logical Maximum (1)
95     0x81, 0x02,                    //   Input (Data, Variable, Absolute)
96 
97     // Reserved byte (input)
98 
99     0x75, 0x01,                    //   Report Size (1)
100     0x95, 0x08,                    //   Report Count (8)
101     0x81, 0x03,                    //   Input (Constant, Variable, Absolute)
102 
103     // LED report + padding (output)
104 
105     0x95, 0x05,                    //   Report Count (5)
106     0x75, 0x01,                    //   Report Size (1)
107     0x05, 0x08,                    //   Usage Page (LEDs)
108     0x19, 0x01,                    //   Usage Minimum (Num Lock)
109     0x29, 0x05,                    //   Usage Maximum (Kana)
110     0x91, 0x02,                    //   Output (Data, Variable, Absolute)
111 
112     0x95, 0x01,                    //   Report Count (1)
113     0x75, 0x03,                    //   Report Size (3)
114     0x91, 0x03,                    //   Output (Constant, Variable, Absolute)
115 
116     // Keycodes (input)
117 
118     0x95, 0x06,                    //   Report Count (6)
119     0x75, 0x08,                    //   Report Size (8)
120     0x15, 0x00,                    //   Logical Minimum (0)
121     0x25, 0xff,                    //   Logical Maximum (1)
122     0x05, 0x07,                    //   Usage Page (Key codes)
123     0x19, 0x00,                    //   Usage Minimum (Reserved (no event indicated))
124     0x29, 0xff,                    //   Usage Maximum (Reserved)
125     0x81, 0x00,                    //   Input (Data, Array)
126 
127     0xc0,                          // End collection
128 };
129 
130 //
131 #define CHAR_ILLEGAL     0xff
132 #define CHAR_RETURN     '\n'
133 #define CHAR_ESCAPE      27
134 #define CHAR_TAB         '\t'
135 #define CHAR_BACKSPACE   0x7f
136 
137 // Simplified US Keyboard with Shift modifier
138 
139 /**
140  * English (US)
141  */
142 static const uint8_t keytable_us_none [] = {
143     CHAR_ILLEGAL, CHAR_ILLEGAL, CHAR_ILLEGAL, CHAR_ILLEGAL,             /*   0-3 */
144     'a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', 'i', 'j',                   /*  4-13 */
145     'k', 'l', 'm', 'n', 'o', 'p', 'q', 'r', 's', 't',                   /* 14-23 */
146     'u', 'v', 'w', 'x', 'y', 'z',                                       /* 24-29 */
147     '1', '2', '3', '4', '5', '6', '7', '8', '9', '0',                   /* 30-39 */
148     CHAR_RETURN, CHAR_ESCAPE, CHAR_BACKSPACE, CHAR_TAB, ' ',            /* 40-44 */
149     '-', '=', '[', ']', '\\', CHAR_ILLEGAL, ';', '\'', 0x60, ',',       /* 45-54 */
150     '.', '/', CHAR_ILLEGAL, CHAR_ILLEGAL, CHAR_ILLEGAL, CHAR_ILLEGAL,   /* 55-60 */
151     CHAR_ILLEGAL, CHAR_ILLEGAL, CHAR_ILLEGAL, CHAR_ILLEGAL,             /* 61-64 */
152     CHAR_ILLEGAL, CHAR_ILLEGAL, CHAR_ILLEGAL, CHAR_ILLEGAL,             /* 65-68 */
153     CHAR_ILLEGAL, CHAR_ILLEGAL, CHAR_ILLEGAL, CHAR_ILLEGAL,             /* 69-72 */
154     CHAR_ILLEGAL, CHAR_ILLEGAL, CHAR_ILLEGAL, CHAR_ILLEGAL,             /* 73-76 */
155     CHAR_ILLEGAL, CHAR_ILLEGAL, CHAR_ILLEGAL, CHAR_ILLEGAL,             /* 77-80 */
156     CHAR_ILLEGAL, CHAR_ILLEGAL, CHAR_ILLEGAL, CHAR_ILLEGAL,             /* 81-84 */
157     '*', '-', '+', '\n', '1', '2', '3', '4', '5',                       /* 85-97 */
158     '6', '7', '8', '9', '0', '.', 0xa7,                                 /* 97-100 */
159 };
160 
161 static const uint8_t keytable_us_shift[] = {
162     CHAR_ILLEGAL, CHAR_ILLEGAL, CHAR_ILLEGAL, CHAR_ILLEGAL,             /*  0-3  */
163     'A', 'B', 'C', 'D', 'E', 'F', 'G', 'H', 'I', 'J',                   /*  4-13 */
164     'K', 'L', 'M', 'N', 'O', 'P', 'Q', 'R', 'S', 'T',                   /* 14-23 */
165     'U', 'V', 'W', 'X', 'Y', 'Z',                                       /* 24-29 */
166     '!', '@', '#', '$', '%', '^', '&', '*', '(', ')',                   /* 30-39 */
167     CHAR_RETURN, CHAR_ESCAPE, CHAR_BACKSPACE, CHAR_TAB, ' ',            /* 40-44 */
168     '_', '+', '{', '}', '|', CHAR_ILLEGAL, ':', '"', 0x7E, '<',         /* 45-54 */
169     '>', '?', CHAR_ILLEGAL, CHAR_ILLEGAL, CHAR_ILLEGAL, CHAR_ILLEGAL,   /* 55-60 */
170     CHAR_ILLEGAL, CHAR_ILLEGAL, CHAR_ILLEGAL, CHAR_ILLEGAL,             /* 61-64 */
171     CHAR_ILLEGAL, CHAR_ILLEGAL, CHAR_ILLEGAL, CHAR_ILLEGAL,             /* 65-68 */
172     CHAR_ILLEGAL, CHAR_ILLEGAL, CHAR_ILLEGAL, CHAR_ILLEGAL,             /* 69-72 */
173     CHAR_ILLEGAL, CHAR_ILLEGAL, CHAR_ILLEGAL, CHAR_ILLEGAL,             /* 73-76 */
174     CHAR_ILLEGAL, CHAR_ILLEGAL, CHAR_ILLEGAL, CHAR_ILLEGAL,             /* 77-80 */
175     CHAR_ILLEGAL, CHAR_ILLEGAL, CHAR_ILLEGAL, CHAR_ILLEGAL,             /* 81-84 */
176     '*', '-', '+', '\n', '1', '2', '3', '4', '5',                       /* 85-97 */
177     '6', '7', '8', '9', '0', '.', 0xb1,                                 /* 97-100 */
178 };
179 
180 // STATE
181 
182 static uint8_t hid_service_buffer[300];
183 static uint8_t device_id_sdp_service_buffer[100];
184 static const char hid_device_name[] = "BTstack HID Keyboard";
185 static btstack_packet_callback_registration_t hci_event_callback_registration;
186 static uint16_t hid_cid;
187 static uint8_t hid_boot_device = 0;
188 
189 // HID Report sending
190 static uint8_t                send_buffer_storage[16];
191 static btstack_ring_buffer_t  send_buffer;
192 static btstack_timer_source_t send_timer;
193 static uint8_t                send_modifier;
194 static uint8_t                send_keycode;
195 static bool                   send_active;
196 
197 #ifdef HAVE_BTSTACK_STDIN
198 static bd_addr_t device_addr;
199 static const char * device_addr_string = "BC:EC:5D:E6:15:03";
200 #endif
201 
202 static enum {
203     APP_BOOTING,
204     APP_NOT_CONNECTED,
205     APP_CONNECTING,
206     APP_CONNECTED
207 } app_state = APP_BOOTING;
208 
209 // HID Keyboard lookup
210 static bool lookup_keycode(uint8_t character, const uint8_t * table, int size, uint8_t * keycode){
211     int i;
212     for (i=0;i<size;i++){
213         if (table[i] != character) continue;
214         *keycode = i;
215         return true;
216     }
217     return false;
218 }
219 
220 static bool keycode_and_modifer_us_for_character(uint8_t character, uint8_t * keycode, uint8_t * modifier){
221     bool found;
222     found = lookup_keycode(character, keytable_us_none, sizeof(keytable_us_none), keycode);
223     if (found) {
224         *modifier = 0;  // none
225         return true;
226     }
227     found = lookup_keycode(character, keytable_us_shift, sizeof(keytable_us_shift), keycode);
228     if (found) {
229         *modifier = 2;  // shift
230         return true;
231     }
232     return false;
233 }
234 
235 static void send_report(int modifier, int keycode){
236     // setup HID message: A1 = Input Report, Report ID, Payload
237     uint8_t message[] = {0xa1, REPORT_ID, modifier, 0, keycode, 0, 0, 0, 0, 0};
238     hid_device_send_interrupt_message(hid_cid, &message[0], sizeof(message));
239 }
240 
241 static void trigger_key_up(btstack_timer_source_t * ts){
242     UNUSED(ts);
243     hid_device_request_can_send_now_event(hid_cid);
244 }
245 
246 static void send_next(btstack_timer_source_t * ts) {
247     // get next key from buffer
248     uint8_t character;
249     uint32_t num_bytes_read = 0;
250     btstack_ring_buffer_read(&send_buffer, &character, 1, &num_bytes_read);
251     if (num_bytes_read == 0) {
252         // buffer empty, nothing to send
253         send_active = false;
254     } else {
255         send_active = true;
256         // lookup keycode and modifier using US layout
257         bool found = keycode_and_modifer_us_for_character(character, &send_keycode, &send_modifier);
258         if (found) {
259             // request can send now
260             hid_device_request_can_send_now_event(hid_cid);
261         } else {
262             // restart timer for next character
263             btstack_run_loop_set_timer(ts, TYPING_DELAY_MS);
264             btstack_run_loop_add_timer(ts);
265         }
266     }
267 }
268 
269 static void queue_character(char character){
270     btstack_ring_buffer_write(&send_buffer, (uint8_t *) &character, 1);
271     if (send_active == false) {
272         send_next(&send_timer);
273     }
274 }
275 
276 // Demo Application
277 
278 #ifdef HAVE_BTSTACK_STDIN
279 
280 // On systems with STDIN, we can directly type on the console
281 
282 static void stdin_process(char character){
283     switch (app_state){
284         case APP_BOOTING:
285         case APP_CONNECTING:
286             // ignore
287             break;
288         case APP_CONNECTED:
289             // add char to send buffer
290             queue_character(character);
291             break;
292         case APP_NOT_CONNECTED:
293             printf("Connecting to %s...\n", bd_addr_to_str(device_addr));
294             hid_device_connect(device_addr, &hid_cid);
295             break;
296         default:
297             btstack_assert(false);
298             break;
299     }
300 }
301 #else
302 
303 // On embedded systems, send constant demo text
304 
305 #define TYPING_DEMO_PERIOD_MS 100
306 
307 static const char * demo_text = "\n\nHello World!\n\nThis is the BTstack HID Keyboard Demo running on an Embedded Device.\n\n";
308 static int demo_pos;
309 static btstack_timer_source_t demo_text_timer;
310 
311 static void demo_text_timer_handler(btstack_timer_source_t * ts){
312     UNUSED(ts);
313 
314     // queue character
315     uint8_t character = demo_text[demo_pos++];
316     if (demo_text[demo_pos] == 0){
317         demo_pos = 0;
318     }
319     queue_character(character);
320 
321     // set timer for next character
322     btstack_run_loop_set_timer_handler(&demo_text_timer, demo_text_timer_handler);
323     btstack_run_loop_set_timer(&demo_text_timer, TYPING_DEMO_PERIOD_MS);
324     btstack_run_loop_add_timer(&demo_text_timer);
325 }
326 
327 #endif
328 
329 static void packet_handler(uint8_t packet_type, uint16_t channel, uint8_t * packet, uint16_t packet_size){
330     UNUSED(channel);
331     UNUSED(packet_size);
332     uint8_t status;
333     switch (packet_type){
334         case HCI_EVENT_PACKET:
335             switch (hci_event_packet_get_type(packet)){
336                 case BTSTACK_EVENT_STATE:
337                     if (btstack_event_state_get_state(packet) != HCI_STATE_WORKING) return;
338                     app_state = APP_NOT_CONNECTED;
339                     break;
340 
341                 case HCI_EVENT_USER_CONFIRMATION_REQUEST:
342                     // ssp: inform about user confirmation request
343                     log_info("SSP User Confirmation Request with numeric value '%06"PRIu32"'\n", hci_event_user_confirmation_request_get_numeric_value(packet));
344                     log_info("SSP User Confirmation Auto accept\n");
345                     break;
346 
347                 case HCI_EVENT_HID_META:
348                     switch (hci_event_hid_meta_get_subevent_code(packet)){
349                         case HID_SUBEVENT_CONNECTION_OPENED:
350                             status = hid_subevent_connection_opened_get_status(packet);
351                             if (status != ERROR_CODE_SUCCESS) {
352                                 // outgoing connection failed
353                                 printf("Connection failed, status 0x%x\n", status);
354                                 app_state = APP_NOT_CONNECTED;
355                                 hid_cid = 0;
356                                 return;
357                             }
358                             app_state = APP_CONNECTED;
359                             hid_cid = hid_subevent_connection_opened_get_hid_cid(packet);
360 #ifdef HAVE_BTSTACK_STDIN
361                             printf("HID Connected, please start typing...\n");
362 #else
363                             printf("HID Connected, sending demo text...\n");
364                             demo_text_timer_handler(NULL);
365 #endif
366                             break;
367                         case HID_SUBEVENT_CONNECTION_CLOSED:
368                             btstack_run_loop_remove_timer(&send_timer);
369                             printf("HID Disconnected\n");
370                             app_state = APP_NOT_CONNECTED;
371                             hid_cid = 0;
372                             break;
373                         case HID_SUBEVENT_CAN_SEND_NOW:
374                             if (send_keycode){
375                                 send_report(send_modifier, send_keycode);
376                                 // schedule key up
377                                 send_keycode = 0;
378                                 send_modifier = 0;
379                                 btstack_run_loop_set_timer_handler(&send_timer, trigger_key_up);
380                                 btstack_run_loop_set_timer(&send_timer, TYPING_KEYDOWN_MS);
381                             } else {
382                                 send_report(0, 0);
383                                 // schedule next key down
384                                 btstack_run_loop_set_timer_handler(&send_timer, send_next);
385                                 btstack_run_loop_set_timer(&send_timer, TYPING_DELAY_MS);
386                             }
387                             btstack_run_loop_add_timer(&send_timer);
388                             break;
389                         default:
390                             break;
391                     }
392                     break;
393                 default:
394                     break;
395             }
396             break;
397         default:
398             break;
399     }
400 }
401 
402 /* @section Main Application Setup
403  *
404  * @text Listing MainConfiguration shows main application code.
405  * To run a HID Device service you need to initialize the SDP, and to create and register HID Device record with it.
406  * At the end the Bluetooth stack is started.
407  */
408 
409 /* LISTING_START(MainConfiguration): Setup HID Device */
410 
411 int btstack_main(int argc, const char * argv[]);
412 int btstack_main(int argc, const char * argv[]){
413     (void)argc;
414     (void)argv;
415 
416     // allow to get found by inquiry
417     gap_discoverable_control(1);
418     // use Limited Discoverable Mode; Peripheral; Keyboard as CoD
419     gap_set_class_of_device(0x2540);
420     // set local name to be identified - zeroes will be replaced by actual BD ADDR
421     gap_set_local_name("HID Keyboard Demo 00:00:00:00:00:00");
422     // allow for role switch in general and sniff mode
423     gap_set_default_link_policy_settings( LM_LINK_POLICY_ENABLE_ROLE_SWITCH | LM_LINK_POLICY_ENABLE_SNIFF_MODE );
424     // allow for role switch on outgoing connections - this allow HID Host to become master when we re-connect to it
425     gap_set_allow_role_switch(true);
426 
427     // L2CAP
428     l2cap_init();
429 
430 #ifdef ENABLE_BLE
431     // Initialize LE Security Manager. Needed for cross-transport key derivation
432     sm_init();
433 #endif
434 
435     // SDP Server
436     sdp_init();
437     memset(hid_service_buffer, 0, sizeof(hid_service_buffer));
438 
439     uint8_t hid_virtual_cable = 0;
440     uint8_t hid_remote_wake = 1;
441     uint8_t hid_reconnect_initiate = 1;
442     uint8_t hid_normally_connectable = 1;
443 
444     hid_sdp_record_t hid_params = {
445         // hid sevice subclass 2540 Keyboard, hid counntry code 33 US
446         0x2540, 33,
447         hid_virtual_cable, hid_remote_wake,
448         hid_reconnect_initiate, hid_normally_connectable,
449         hid_boot_device,
450         host_max_latency, host_min_timeout,
451         3200,
452         hid_descriptor_keyboard,
453         sizeof(hid_descriptor_keyboard),
454         hid_device_name
455     };
456 
457     hid_create_sdp_record(hid_service_buffer, sdp_create_service_record_handle(), &hid_params);
458     btstack_assert(de_get_len( hid_service_buffer) <= sizeof(hid_service_buffer));
459     sdp_register_service(hid_service_buffer);
460 
461     // See https://www.bluetooth.com/specifications/assigned-numbers/company-identifiers if you don't have a USB Vendor ID and need a Bluetooth Vendor ID
462     // device info: BlueKitchen GmbH, product 1, version 1
463     device_id_create_sdp_record(device_id_sdp_service_buffer, sdp_create_service_record_handle(), DEVICE_ID_VENDOR_ID_SOURCE_BLUETOOTH, BLUETOOTH_COMPANY_ID_BLUEKITCHEN_GMBH, 1, 1);
464     btstack_assert(de_get_len( device_id_sdp_service_buffer) <= sizeof(device_id_sdp_service_buffer));
465     sdp_register_service(device_id_sdp_service_buffer);
466 
467     // HID Device
468     hid_device_init(hid_boot_device, sizeof(hid_descriptor_keyboard), hid_descriptor_keyboard);
469 
470     // register for HCI events
471     hci_event_callback_registration.callback = &packet_handler;
472     hci_add_event_handler(&hci_event_callback_registration);
473 
474     // register for HID events
475     hid_device_register_packet_handler(&packet_handler);
476 
477 #ifdef HAVE_BTSTACK_STDIN
478     sscanf_bd_addr(device_addr_string, device_addr);
479     btstack_stdin_setup(stdin_process);
480 #endif
481 
482     btstack_ring_buffer_init(&send_buffer, send_buffer_storage, sizeof(send_buffer_storage));
483 
484     // turn on!
485     hci_power_control(HCI_POWER_ON);
486     return 0;
487 }
488 /* LISTING_END */
489 /* EXAMPLE_END */
490