xref: /btstack/src/ble/gatt-service/cycling_power_service_server.c (revision 3c4cc6427fe05577c00b7d2593f58c7abcf9eab7)
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 MATTHIAS
24  * RINGWALD 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__ "cycling_power_service_server.c"
39 
40 
41 #include "bluetooth.h"
42 #include "btstack_defines.h"
43 #include "bluetooth_data_types.h"
44 #include "btstack_event.h"
45 #include "ble/att_db.h"
46 #include "ble/att_server.h"
47 #include "btstack_util.h"
48 #include "bluetooth_gatt.h"
49 #include "btstack_debug.h"
50 #include "l2cap.h"
51 #include "hci.h"
52 
53 #include "ble/gatt-service/cycling_power_service_server.h"
54 
55 #define CYCLING_POWER_MAX_BROACAST_MSG_SIZE         31
56 #define CONTROL_POINT_PROCEDURE_TIMEOUT_MS          30
57 #define CYCLING_POWER_MEASUREMENT_FLAGS_CLEARED     0xFFFF
58 
59 typedef enum {
60     CP_MASK_BIT_PEDAL_POWER_BALANCE = 0,
61     CP_MASK_BIT_ACCUMULATED_TORQUE,
62     CP_MASK_BIT_WHEEL_REVOLUTION_DATA,
63     CP_MASK_BIT_CRANK_REVOLUTION_DATA,
64     CP_MASK_BIT_EXTREME_MAGNITUDES,
65     CP_MASK_BIT_EXTREME_ANGLES,
66     CP_MASK_BIT_TOP_DEAD_SPOT_ANGLE,
67     CP_MASK_BIT_BOTTOM_DEAD_SPOT_ANGLE,
68     CP_MASK_BIT_ACCUMULATED_ENERGY,
69     CP_MASK_BIT_RESERVED
70 } cycling_power_mask_bit_t;
71 
72 typedef enum {
73     CP_OPCODE_IDLE = 0,
74     CP_OPCODE_SET_CUMULATIVE_VALUE,
75     CP_OPCODE_UPDATE_SENSOR_LOCATION,
76     CP_OPCODE_REQUEST_SUPPORTED_SENSOR_LOCATIONS,
77     CP_OPCODE_SET_CRANK_LENGTH,
78     CP_OPCODE_REQUEST_CRANK_LENGTH,
79     CP_OPCODE_SET_CHAIN_LENGTH,
80     CP_OPCODE_REQUEST_CHAIN_LENGTH,
81     CP_OPCODE_SET_CHAIN_WEIGHT,
82     CP_OPCODE_REQUEST_CHAIN_WEIGHT,
83     CP_OPCODE_SET_SPAN_LENGTH,
84     CP_OPCODE_REQUEST_SPAN_LENGTH,
85     CP_OPCODE_START_OFFSET_COMPENSATION,
86     CP_OPCODE_MASK_CYCLING_POWER_MEASUREMENT_CHARACTERISTIC_CONTENT,
87     CP_OPCODE_REQUEST_SAMPLING_RATE,
88     CP_OPCODE_REQUEST_FACTORY_CALIBRATION_DATE,
89     CP_OPCODE_START_ENHANCED_OFFSET_COMPENSATION,
90     CP_OPCODE_RESPONSE_CODE = 32
91 } cycling_power_opcode_t;
92 
93 typedef enum {
94     CP_RESPONSE_VALUE_SUCCESS = 1,
95     CP_RESPONSE_VALUE_OP_CODE_NOT_SUPPORTED,
96     CP_RESPONSE_VALUE_INVALID_PARAMETER,
97     CP_RESPONSE_VALUE_OPERATION_FAILED,
98     CP_RESPONSE_VALUE_NOT_AVAILABLE,
99     CP_RESPONSE_VALUE_W4_VALUE_AVAILABLE
100 } cycling_power_response_value_t;
101 
102 typedef enum {
103     CP_CONNECTION_INTERVAL_STATUS_NONE = 0,
104     CP_CONNECTION_INTERVAL_STATUS_RECEIVED,
105     CP_CONNECTION_INTERVAL_STATUS_ACCEPTED,
106     CP_CONNECTION_INTERVAL_STATUS_W4_L2CAP_RESPONSE,
107     CP_CONNECTION_INTERVAL_STATUS_W4_UPDATE,
108     CP_CONNECTION_INTERVAL_STATUS_REJECTED
109 } cycling_power_con_interval_status_t;
110 
111 typedef struct {
112     hci_con_handle_t con_handle;
113     // GATT connection management
114     uint16_t con_interval;
115     uint16_t con_interval_min;
116     uint16_t con_interval_max;
117     cycling_power_con_interval_status_t  con_interval_status;
118 
119     // Cycling Power Measurement
120     uint16_t measurement_value_handle;
121     int16_t  instantaneous_power_watt;
122 
123     cycling_power_pedal_power_balance_reference_t  pedal_power_balance_reference;
124     uint8_t  pedal_power_balance_percentage;    // percentage, resolution 1/2,
125                                                 // If the sensor provides the power balance referenced to the left pedal,
126                                                 // the power balance is calculated as [LeftPower/(LeftPower + RightPower)]*100 in units of percent
127 
128     cycling_power_torque_source_t torque_source;
129     uint16_t accumulated_torque_m;              // meters, resolution 1/32,
130                                                 // The Accumulated Torque value may decrease
131     // wheel revolution data:
132     uint32_t cumulative_wheel_revolutions;      // CANNOT roll over
133     uint16_t last_wheel_event_time_s;           // seconds, resolution 1/2048
134     // crank revolution data:
135     uint16_t cumulative_crank_revolutions;
136     uint16_t last_crank_event_time_s;           // seconds, resolution 1/1024
137     // extreme force magnitudes
138     int16_t  maximum_force_magnitude_newton;
139     int16_t  minimum_force_magnitude_newton;
140     int16_t  maximum_torque_magnitude_newton_m;     // newton meters, resolution 1/32
141     int16_t  minimum_torque_magnitude_newton_m;     // newton meters, resolution 1/32
142     // extreme angles
143     uint16_t maximum_angle_deg;                 // 12bit, degrees
144     uint16_t minimum_angle_deg;                 // 12bit, degrees, concatenated with previous into 3 octets
145                                                 // i.e. if the Maximum Angle is 0xABC and the Minimum Angle is 0x123, the transmitted value is 0x123ABC.
146     uint16_t top_dead_spot_angle_deg;
147     uint16_t bottom_dead_spot_angle_deg;            // The Bottom Dead Spot Angle field represents the crank angle when the value of the Instantaneous Power value becomes negative.
148     uint16_t accumulated_energy_kJ;             // kilojoules; CANNOT roll over
149 
150     // uint8_t  offset_compensation;
151 
152     // CP Measurement Notification (Client Characteristic Configuration)
153     uint16_t measurement_client_configuration_descriptor_handle;
154     uint16_t measurement_client_configuration_descriptor_notify;
155     btstack_context_callback_registration_t measurement_notify_callback;
156 
157     // CP Measurement Broadcast (Server Characteristic Configuration)
158     uint16_t measurement_server_configuration_descriptor_handle;
159     uint16_t measurement_server_configuration_descriptor_broadcast;
160     btstack_context_callback_registration_t measurement_broadcast_callback;
161 
162     // Cycling Power Feature
163     uint16_t feature_value_handle;
164     uint32_t feature_flags;                             // see cycling_power_feature_flag_t
165     uint16_t masked_measurement_flags;
166     uint16_t default_measurement_flags;
167 
168     // Sensor Location
169     uint16_t sensor_location_value_handle;
170     cycling_power_sensor_location_t sensor_location;    // see cycling_power_sensor_location_t
171     cycling_power_sensor_location_t * supported_sensor_locations;
172     uint16_t num_supported_sensor_locations;
173     uint16_t crank_length_mm;                           // resolution 1/2 mm
174     uint16_t chain_length_mm;                           // resolution 1 mm
175     uint16_t chain_weight_g;                            // resolution 1 gram
176     uint16_t span_length_mm;                            // resolution 1 mm
177 
178     gatt_date_time_t factory_calibration_date;
179 
180     uint8_t  sampling_rate_hz;                          // resolution 1 Herz
181 
182     int16_t  current_force_magnitude_newton;
183     int16_t  current_torque_magnitude_newton_m;     // newton meters, resolution 1/32
184     uint16_t manufacturer_company_id;
185     uint8_t num_manufacturer_specific_data;
186     uint8_t * manufacturer_specific_data;
187 
188     // Cycling Power Vector
189     uint16_t vector_value_handle;
190     uint16_t vector_cumulative_crank_revolutions;
191     uint16_t vector_last_crank_event_time_s;                            // seconds, resolution 1/1024
192     uint16_t vector_first_crank_measurement_angle_deg;
193     int16_t  * vector_instantaneous_force_magnitude_newton_array;           // newton
194     int force_magnitude_count;
195     int16_t  * vector_instantaneous_torque_magnitude_newton_per_m_array;    // newton per meter, resolution 1/32
196     int torque_magnitude_count;
197     cycling_power_instantaneous_measurement_direction_t vector_instantaneous_measurement_direction;
198 
199     // CP Vector Notification (Client Characteristic Configuration)
200     uint16_t vector_client_configuration_descriptor_handle;
201     uint16_t vector_client_configuration_descriptor_notify;
202     btstack_context_callback_registration_t vector_notify_callback;
203 
204     // CP Control Point
205     uint16_t control_point_value_handle;
206     // CP Control Point Indication (Client Characteristic Configuration)
207     uint16_t control_point_client_configuration_descriptor_handle;
208     uint16_t control_point_client_configuration_descriptor_indicate;
209     btstack_context_callback_registration_t control_point_indicate_callback;
210 
211     cycling_power_opcode_t request_opcode;
212     cycling_power_response_value_t response_value;
213 
214     btstack_packet_handler_t calibration_callback;
215     uint8_t w4_indication_complete;
216 } cycling_power_t;
217 
218 static att_service_handler_t cycling_power_service;
219 static cycling_power_t cycling_power;
220 static btstack_packet_callback_registration_t hci_event_callback_registration;
221 
222 static uint16_t cycling_power_service_read_callback(hci_con_handle_t con_handle, uint16_t attribute_handle, uint16_t offset, uint8_t * buffer, uint16_t buffer_size){
223     UNUSED(con_handle);
224     UNUSED(attribute_handle);
225     UNUSED(offset);
226     cycling_power_t * instance = &cycling_power;
227 
228     if (attribute_handle == instance->measurement_client_configuration_descriptor_handle){
229         if (buffer && buffer_size >= 2){
230             little_endian_store_16(buffer, 0, instance->measurement_client_configuration_descriptor_notify);
231         }
232         return 2;
233     }
234 
235     if (attribute_handle == instance->measurement_server_configuration_descriptor_handle){
236         if (buffer && buffer_size >= 2){
237             little_endian_store_16(buffer, 0, instance->measurement_server_configuration_descriptor_broadcast);
238         }
239         return 2;
240     }
241 
242     if (attribute_handle == instance->vector_client_configuration_descriptor_handle){
243         if (buffer && buffer_size >= 2){
244             little_endian_store_16(buffer, 0, instance->vector_client_configuration_descriptor_notify);
245         }
246         return 2;
247     }
248 
249     if (attribute_handle == instance->control_point_client_configuration_descriptor_handle){
250         if (buffer && buffer_size >= 2){
251             little_endian_store_16(buffer, 0, instance->control_point_client_configuration_descriptor_indicate);
252         }
253         return 2;
254     }
255 
256     if (attribute_handle == instance->feature_value_handle){
257         if (buffer && buffer_size >= 4){
258             little_endian_store_32(buffer, 0, instance->feature_flags);
259         }
260         return 4;
261     }
262 
263     if (attribute_handle == instance->sensor_location_value_handle){
264         if (buffer && buffer_size >= 1){
265             buffer[0] = instance->sensor_location;
266         }
267         return 1;
268     }
269     return 0;
270 }
271 
272 static int has_feature(cycling_power_feature_flag_t feature){
273     cycling_power_t * instance = &cycling_power;
274     return (instance->feature_flags & (1 << feature)) != 0;
275 }
276 
277 static int cycling_power_vector_instantaneous_measurement_direction(void){
278     cycling_power_t * instance = &cycling_power;
279     return instance->vector_instantaneous_measurement_direction;
280 }
281 
282 static uint16_t cycling_power_service_default_measurement_flags(void){
283     cycling_power_t * instance = &cycling_power;
284     uint16_t measurement_flags = 0;
285     uint8_t flag[] = {
286         (uint8_t) has_feature(CP_FEATURE_FLAG_PEDAL_POWER_BALANCE_SUPPORTED),
287         (uint8_t) has_feature(CP_FEATURE_FLAG_PEDAL_POWER_BALANCE_SUPPORTED) && instance->pedal_power_balance_reference,
288         (uint8_t) has_feature(CP_FEATURE_FLAG_ACCUMULATED_TORQUE_SUPPORTED),
289         (uint8_t) has_feature(CP_FEATURE_FLAG_ACCUMULATED_TORQUE_SUPPORTED) && instance->torque_source,
290         (uint8_t) has_feature(CP_FEATURE_FLAG_WHEEL_REVOLUTION_DATA_SUPPORTED),
291         (uint8_t) has_feature(CP_FEATURE_FLAG_CRANK_REVOLUTION_DATA_SUPPORTED),
292         (uint8_t) has_feature(CP_FEATURE_FLAG_EXTREME_MAGNITUDES_SUPPORTED) && (has_feature(CP_FEATURE_FLAG_SENSOR_MEASUREMENT_CONTEXT) == CP_SENSOR_MEASUREMENT_CONTEXT_FORCE),
293         (uint8_t) has_feature(CP_FEATURE_FLAG_EXTREME_MAGNITUDES_SUPPORTED) && (has_feature(CP_FEATURE_FLAG_SENSOR_MEASUREMENT_CONTEXT) == CP_SENSOR_MEASUREMENT_CONTEXT_TORQUE),
294         (uint8_t) has_feature(CP_FEATURE_FLAG_EXTREME_ANGLES_SUPPORTED),
295         (uint8_t) has_feature(CP_FEATURE_FLAG_TOP_AND_BOTTOM_DEAD_SPOT_ANGLE_SUPPORTED),
296         (uint8_t) has_feature(CP_FEATURE_FLAG_TOP_AND_BOTTOM_DEAD_SPOT_ANGLE_SUPPORTED),
297         (uint8_t) has_feature(CP_FEATURE_FLAG_ACCUMULATED_ENERGY_SUPPORTED),
298         (uint8_t) has_feature(CP_FEATURE_FLAG_OFFSET_COMPENSATION_INDICATOR_SUPPORTED)
299     };
300 
301     int i;
302     for (i = CP_MEASUREMENT_FLAG_PEDAL_POWER_BALANCE_PRESENT; i <= CP_MEASUREMENT_FLAG_OFFSET_COMPENSATION_INDICATOR; i++){
303         measurement_flags |= flag[i] << i;
304     }
305 
306     return measurement_flags;
307 }
308 
309 static uint16_t cycling_power_service_get_measurement_flags(cycling_power_t * instance){
310     if (!instance) return 0;
311     if (instance->masked_measurement_flags != CYCLING_POWER_MEASUREMENT_FLAGS_CLEARED){
312         return instance->masked_measurement_flags;
313     }
314     if (instance->default_measurement_flags == CYCLING_POWER_MEASUREMENT_FLAGS_CLEARED){
315         instance->default_measurement_flags = cycling_power_service_default_measurement_flags();
316     }
317     return instance->default_measurement_flags;
318 }
319 
320 
321 uint16_t cycling_power_service_measurement_flags(void){
322     cycling_power_t * instance = &cycling_power;
323     return cycling_power_service_get_measurement_flags(instance);
324 }
325 
326 uint8_t cycling_power_service_vector_flags(void){
327     uint8_t vector_flags = 0;
328     uint8_t flag[] = {
329         (uint8_t )has_feature(CP_FEATURE_FLAG_CRANK_REVOLUTION_DATA_SUPPORTED),
330         (uint8_t )has_feature(CP_FEATURE_FLAG_EXTREME_ANGLES_SUPPORTED),
331         (uint8_t )has_feature(CP_FEATURE_FLAG_EXTREME_MAGNITUDES_SUPPORTED) && (has_feature(CP_FEATURE_FLAG_SENSOR_MEASUREMENT_CONTEXT) == CP_SENSOR_MEASUREMENT_CONTEXT_FORCE),
332         (uint8_t )has_feature(CP_FEATURE_FLAG_EXTREME_MAGNITUDES_SUPPORTED) && (has_feature(CP_FEATURE_FLAG_SENSOR_MEASUREMENT_CONTEXT) == CP_SENSOR_MEASUREMENT_CONTEXT_TORQUE),
333         (uint8_t )has_feature(CP_FEATURE_FLAG_INSTANTANEOUS_MEASUREMENT_DIRECTION_SUPPORTED) && cycling_power_vector_instantaneous_measurement_direction()
334     };
335 
336     int i;
337     for (i = CP_VECTOR_FLAG_CRANK_REVOLUTION_DATA_PRESENT; i <= CP_VECTOR_FLAG_INSTANTANEOUS_MEASUREMENT_DIRECTION; i++){
338         vector_flags |= flag[i] << i;
339     }
340     return vector_flags;
341 }
342 
343 static void cycling_power_service_vector_can_send_now(void * context){
344     cycling_power_t * instance = (cycling_power_t *) context;
345     if (!instance){
346         log_error("cycling_power_service_measurement_can_send_now: instance is null");
347         return;
348     }
349     uint8_t value[50];
350     uint8_t vector_flags = cycling_power_service_vector_flags();
351     int pos = 0;
352 
353     value[pos++] = vector_flags;
354     int i;
355     for (i = CP_VECTOR_FLAG_CRANK_REVOLUTION_DATA_PRESENT; i <= CP_VECTOR_FLAG_INSTANTANEOUS_MEASUREMENT_DIRECTION; i++){
356         if ((vector_flags & (1 << i)) == 0) continue;
357         switch ((cycling_power_vector_flag_t) i){
358             case CP_VECTOR_FLAG_CRANK_REVOLUTION_DATA_PRESENT:
359                 little_endian_store_16(value, pos, instance->cumulative_crank_revolutions);
360                 pos += 2;
361                 little_endian_store_16(value, pos, instance->last_crank_event_time_s);
362                 pos += 2;
363                 break;
364             case CP_VECTOR_FLAG_INSTANTANEOUS_FORCE_MAGNITUDE_ARRAY_PRESENT:{
365                 uint16_t att_mtu = att_server_get_mtu(instance->con_handle);
366                 uint16_t bytes_left = 0;
367                 if (att_mtu > pos + 3){
368                     bytes_left = btstack_min(sizeof(value), att_mtu - 3 - pos);
369                 }
370                 while (bytes_left > 2 && instance->force_magnitude_count){
371                     little_endian_store_16(value, pos, instance->vector_instantaneous_force_magnitude_newton_array[0]);
372                     pos += 2;
373                     bytes_left -= 2;
374                     instance->vector_instantaneous_force_magnitude_newton_array++;
375                     instance->force_magnitude_count--;
376                 }
377                 break;
378             }
379             case CP_VECTOR_FLAG_INSTANTANEOUS_TORQUE_MAGNITUDE_ARRAY_PRESENT:{
380                 uint16_t att_mtu = att_server_get_mtu(instance->con_handle);
381                 uint16_t bytes_left = 0;
382                 if (att_mtu > pos + 3){
383                     bytes_left = btstack_min(sizeof(value), att_mtu - 3 - pos);
384                 }
385 
386                 while (bytes_left > 2 && instance->torque_magnitude_count){
387                     little_endian_store_16(value, pos, instance->vector_instantaneous_torque_magnitude_newton_per_m_array[0]);
388                     pos += 2;
389                     bytes_left -= 2;
390                     instance->vector_instantaneous_torque_magnitude_newton_per_m_array++;
391                     instance->torque_magnitude_count--;
392                 }
393                 break;
394             }
395             case CP_VECTOR_FLAG_FIRST_CRANK_MEASUREMENT_ANGLE_PRESENT:
396                 // printf("CP_VECTOR_FLAG_FIRST_CRANK_MEASUREMENT_ANGLE_PRESENT \n");
397                 little_endian_store_16(value, pos, instance->vector_first_crank_measurement_angle_deg);
398                 pos += 2;
399                 break;
400             case CP_VECTOR_FLAG_INSTANTANEOUS_MEASUREMENT_DIRECTION:
401                 break;
402             default:
403                 break;
404         }
405     }
406 
407     att_server_notify(instance->con_handle, instance->vector_value_handle, &value[0], pos);
408 }
409 
410 static int cycling_power_measurement_flag_value_size(cycling_power_measurement_flag_t flag){
411     switch (flag){
412         case CP_MEASUREMENT_FLAG_PEDAL_POWER_BALANCE_PRESENT:
413             return 1;
414         case CP_MEASUREMENT_FLAG_WHEEL_REVOLUTION_DATA_PRESENT:
415             return 6;
416         case CP_MEASUREMENT_FLAG_CRANK_REVOLUTION_DATA_PRESENT:
417         case CP_MEASUREMENT_FLAG_EXTREME_FORCE_MAGNITUDES_PRESENT:
418         case CP_MEASUREMENT_FLAG_EXTREME_TORQUE_MAGNITUDES_PRESENT:
419             return 4;
420         case CP_MEASUREMENT_FLAG_EXTREME_ANGLES_PRESENT:
421             return 3;
422         case CP_MEASUREMENT_FLAG_ACCUMULATED_TORQUE_PRESENT:
423         case CP_MEASUREMENT_FLAG_TOP_DEAD_SPOT_ANGLE_PRESENT:
424         case CP_MEASUREMENT_FLAG_BOTTOM_DEAD_SPOT_ANGLE_PRESENT:
425         case CP_MEASUREMENT_FLAG_ACCUMULATED_ENERGY_PRESENT:
426             return 2;
427         default:
428             return 0;
429     }
430 }
431 
432 static int cycling_power_store_measurement_flag_value(cycling_power_t * instance, cycling_power_measurement_flag_t flag, uint8_t * value){
433     if (!instance) return 0;
434 
435     int pos = 0;
436     switch (flag){
437         case CP_MEASUREMENT_FLAG_PEDAL_POWER_BALANCE_PRESENT:
438             value[pos++] = instance->pedal_power_balance_percentage;
439             break;
440         case CP_MEASUREMENT_FLAG_ACCUMULATED_TORQUE_PRESENT:
441             little_endian_store_16(value, pos, instance->accumulated_torque_m);
442             pos += 2;
443             break;
444         case CP_MEASUREMENT_FLAG_WHEEL_REVOLUTION_DATA_PRESENT:
445             little_endian_store_32(value, pos, instance->cumulative_wheel_revolutions);
446             pos += 4;
447             little_endian_store_16(value, pos, instance->last_wheel_event_time_s);
448             pos += 2;
449             break;
450         case CP_MEASUREMENT_FLAG_CRANK_REVOLUTION_DATA_PRESENT:
451             little_endian_store_16(value, pos, instance->cumulative_crank_revolutions);
452             pos += 2;
453             little_endian_store_16(value, pos, instance->last_crank_event_time_s);
454             pos += 2;
455             break;
456         case CP_MEASUREMENT_FLAG_EXTREME_FORCE_MAGNITUDES_PRESENT:
457             little_endian_store_16(value, pos, (uint16_t)instance->maximum_force_magnitude_newton);
458             pos += 2;
459             little_endian_store_16(value, pos, (uint16_t)instance->minimum_force_magnitude_newton);
460             pos += 2;
461             break;
462         case CP_MEASUREMENT_FLAG_EXTREME_TORQUE_MAGNITUDES_PRESENT:
463             little_endian_store_16(value, pos, (uint16_t)instance->maximum_torque_magnitude_newton_m);
464             pos += 2;
465             little_endian_store_16(value, pos, (uint16_t)instance->minimum_torque_magnitude_newton_m);
466             pos += 2;
467             break;
468         case CP_MEASUREMENT_FLAG_EXTREME_ANGLES_PRESENT:
469             little_endian_store_24(value, pos, (instance->maximum_angle_deg << 12) | instance->minimum_angle_deg);
470             pos += 3;
471             break;
472         case CP_MEASUREMENT_FLAG_TOP_DEAD_SPOT_ANGLE_PRESENT:
473             little_endian_store_16(value, pos, (uint16_t)instance->top_dead_spot_angle_deg);
474             pos += 2;
475             break;
476         case CP_MEASUREMENT_FLAG_BOTTOM_DEAD_SPOT_ANGLE_PRESENT:
477             little_endian_store_16(value, pos, (uint16_t)instance->bottom_dead_spot_angle_deg);
478             pos += 2;
479             break;
480         case CP_MEASUREMENT_FLAG_ACCUMULATED_ENERGY_PRESENT:
481             little_endian_store_16(value, pos, (uint16_t)instance->accumulated_energy_kJ);
482             pos += 2;
483             break;
484         default:
485             break;
486     }
487     return pos;
488 }
489 
490 
491 static int cycling_power_store_measurement(cycling_power_t * instance, uint8_t * value, uint16_t max_value_size){
492     if (max_value_size < 4) return 0;
493     if (!instance) return 0;
494 
495     uint16_t measurement_flags = cycling_power_service_get_measurement_flags(instance);
496     int pos = 0;
497     little_endian_store_16(value, 0, measurement_flags);
498     pos += 2;
499     little_endian_store_16(value, 2, instance->instantaneous_power_watt);
500     pos += 2;
501     int flag_index;
502     uint16_t bytes_left = max_value_size - pos;
503     for (flag_index = 0; flag_index < CP_MEASUREMENT_FLAG_RESERVED; flag_index++){
504         if ((measurement_flags & (1 << flag_index)) == 0) continue;
505         cycling_power_measurement_flag_t flag = (cycling_power_measurement_flag_t) flag_index;
506         uint16_t value_size = cycling_power_measurement_flag_value_size(flag);
507         if (value_size > bytes_left ) return pos;
508         cycling_power_store_measurement_flag_value(instance, flag, &value[pos]);
509         pos += value_size;
510         bytes_left -= value_size;
511     }
512     return pos;
513 }
514 
515 int cycling_power_get_measurement_adv(uint16_t adv_interval, uint8_t * broadcast_adv, uint16_t max_value_size){
516     if (max_value_size < 12) return 0;
517     cycling_power_t * instance =  &cycling_power;
518     int pos = 0;
519     // adv flags
520     broadcast_adv[pos++] = 2;
521     broadcast_adv[pos++] = BLUETOOTH_DATA_TYPE_FLAGS;
522     broadcast_adv[pos++] = 0x4;
523 
524     // adv interval
525     broadcast_adv[pos++] = 3;
526     broadcast_adv[pos++] = BLUETOOTH_DATA_TYPE_ADVERTISING_INTERVAL;
527     little_endian_store_16(broadcast_adv, pos, adv_interval);
528     pos += 2;
529     //
530     int value_len = cycling_power_store_measurement(instance, &broadcast_adv[pos+4], CYCLING_POWER_MAX_BROACAST_MSG_SIZE - (pos + 4));
531     broadcast_adv[pos++] = 3 + value_len;
532     broadcast_adv[pos++] = BLUETOOTH_DATA_TYPE_SERVICE_DATA_16_BIT_UUID;
533     little_endian_store_16(broadcast_adv, pos, ORG_BLUETOOTH_SERVICE_CYCLING_POWER);
534     pos += 2;
535     // value data already in place cycling_power_get_measurement
536     pos += value_len;
537     // set ADV_NONCONN_IND
538     return pos;
539 }
540 
541 static void cycling_power_service_broadcast_can_send_now(void * context){
542     cycling_power_t * instance = (cycling_power_t *) context;
543     if (!instance){
544         log_error("cycling_power_service_broadcast_can_send_now: instance is null");
545         return;
546     }
547     uint8_t value[CYCLING_POWER_MAX_BROACAST_MSG_SIZE];
548     int pos = cycling_power_store_measurement(instance, &value[0], sizeof(value));
549     att_server_notify(instance->con_handle, instance->measurement_value_handle, &value[0], pos);
550 }
551 
552 static void cycling_power_service_measurement_can_send_now(void * context){
553     cycling_power_t * instance = (cycling_power_t *) context;
554     if (!instance){
555         log_error("cycling_power_service_measurement_can_send_now: instance is null");
556         return;
557     }
558     uint8_t value[40];
559     int pos = cycling_power_store_measurement(instance, &value[0], sizeof(value));
560     att_server_notify(instance->con_handle, instance->measurement_value_handle, &value[0], pos);
561 }
562 
563 static void cycling_power_service_response_can_send_now(void * context){
564     cycling_power_t * instance = (cycling_power_t *) context;
565     if (!instance){
566         log_error("cycling_power_service_response_can_send_now: instance is null");
567         return;
568     }
569 
570     if (instance->response_value == CP_RESPONSE_VALUE_W4_VALUE_AVAILABLE){
571         log_error("cycling_power_service_response_can_send_now: CP_RESPONSE_VALUE_W4_VALUE_AVAILABLE");
572         return;
573     }
574 
575     // if (instance->w4_indication_complete){
576     //     printf("cycling_power_service_response_can_send_now: w4_indication_complete\n");
577     //     return;
578     // }
579 
580     uint8_t value[3 + btstack_max(CP_SENSOR_LOCATION_RESERVED, CYCLING_POWER_MANUFACTURER_SPECIFIC_DATA_MAX_SIZE + 5)];
581     int pos = 0;
582     value[pos++] = CP_OPCODE_RESPONSE_CODE;
583     value[pos++] = instance->request_opcode;
584     value[pos++] = instance->response_value;
585     if (instance->response_value == CP_RESPONSE_VALUE_SUCCESS){
586         switch (instance->request_opcode){
587             case CP_OPCODE_REQUEST_SUPPORTED_SENSOR_LOCATIONS:{
588                 int i;
589                 for (i=0; i<instance->num_supported_sensor_locations; i++){
590                     value[pos++] = instance->supported_sensor_locations[i];
591                 }
592                 break;
593             }
594             case CP_OPCODE_REQUEST_CRANK_LENGTH:
595                 little_endian_store_16(value, pos, instance->crank_length_mm);
596                 pos += 2;
597                 break;
598             case CP_OPCODE_REQUEST_CHAIN_LENGTH:
599                 little_endian_store_16(value, pos, instance->chain_length_mm);
600                 pos += 2;
601                 break;
602             case CP_OPCODE_REQUEST_CHAIN_WEIGHT:
603                 little_endian_store_16(value, pos, instance->chain_weight_g);
604                 pos += 2;
605                 break;
606             case CP_OPCODE_REQUEST_SPAN_LENGTH:
607                 little_endian_store_16(value, pos, instance->span_length_mm);
608                 pos += 2;
609                 break;
610             case CP_OPCODE_REQUEST_FACTORY_CALIBRATION_DATE:
611                 little_endian_store_16(value, pos, instance->factory_calibration_date.year);
612                 pos += 2;
613                 value[pos++] = instance->factory_calibration_date.month;
614                 value[pos++] = instance->factory_calibration_date.day;
615                 value[pos++] = instance->factory_calibration_date.hours;
616                 value[pos++] = instance->factory_calibration_date.minutes;
617                 value[pos++] = instance->factory_calibration_date.seconds;
618                 break;
619             case CP_OPCODE_REQUEST_SAMPLING_RATE:
620                 value[pos++] = instance->sampling_rate_hz;
621                 break;
622             case CP_OPCODE_START_OFFSET_COMPENSATION:
623             case CP_OPCODE_START_ENHANCED_OFFSET_COMPENSATION:{
624                 uint16_t calibrated_value = 0xffff;
625                 if (has_feature(CP_FEATURE_FLAG_EXTREME_MAGNITUDES_SUPPORTED)){
626                     if (has_feature(CP_FEATURE_FLAG_SENSOR_MEASUREMENT_CONTEXT) == CP_SENSOR_MEASUREMENT_CONTEXT_FORCE) {
627                         calibrated_value = instance->current_force_magnitude_newton;
628                     } else if (has_feature(CP_FEATURE_FLAG_SENSOR_MEASUREMENT_CONTEXT) == CP_SENSOR_MEASUREMENT_CONTEXT_TORQUE){
629                         calibrated_value = instance->current_torque_magnitude_newton_m;
630                     }
631                 }
632 
633                 if (calibrated_value == CP_CALIBRATION_STATUS_INCORRECT_CALIBRATION_POSITION){
634                      value[pos++] = calibrated_value;
635                      // do not include manufacturer ID and data
636                      break;
637                 } else if (calibrated_value == CP_CALIBRATION_STATUS_MANUFACTURER_SPECIFIC_ERROR_FOLLOWS){
638                     value[pos++] = calibrated_value;
639                 } else {
640                     little_endian_store_16(value, pos, calibrated_value);
641                     pos += 2;
642 
643                 }
644 
645                 if (instance->request_opcode == CP_OPCODE_START_OFFSET_COMPENSATION) break;
646                 little_endian_store_16(value, pos, instance->manufacturer_company_id);
647                 pos += 2;
648                 int data_len = instance->num_manufacturer_specific_data < CYCLING_POWER_MANUFACTURER_SPECIFIC_DATA_MAX_SIZE ? instance->num_manufacturer_specific_data : (CYCLING_POWER_MANUFACTURER_SPECIFIC_DATA_MAX_SIZE - 1);
649                 value[pos++] = data_len;
650                 memcpy(&value[pos], instance->manufacturer_specific_data, data_len);
651                 pos += data_len;
652                 value[pos++] = 0;
653                 break;
654             }
655             case CP_OPCODE_MASK_CYCLING_POWER_MEASUREMENT_CHARACTERISTIC_CONTENT:
656                 break;
657             default:
658                 break;
659         }
660     }
661     uint8_t status = att_server_indicate(instance->con_handle, instance->control_point_value_handle, &value[0], pos);
662     if (status == ERROR_CODE_SUCCESS){
663         instance->w4_indication_complete = 1;
664         // printf("cycling_power_service_response_can_send_now: set w4_indication_complete\n");
665         // printf("can_send_now set opcode to CP_OPCODE_IDLE\n");
666         instance->request_opcode = CP_OPCODE_IDLE;
667     } else {
668         log_error("can_send_now failed 0x%2x", status);
669     }
670 }
671 
672 static int cycling_power_service_write_callback(hci_con_handle_t con_handle, uint16_t attribute_handle, uint16_t transaction_mode, uint16_t offset, uint8_t *buffer, uint16_t buffer_size){
673     UNUSED(con_handle);
674     UNUSED(transaction_mode);
675     UNUSED(offset);
676     UNUSED(buffer_size);
677     int i;
678     cycling_power_sensor_location_t location;
679     cycling_power_t * instance = &cycling_power;
680 
681     // printf("cycling_power_service_write_callback: attr handle 0x%02x\n", attribute_handle);
682     if (attribute_handle == instance->measurement_client_configuration_descriptor_handle){
683         if (buffer_size < 2){
684             return ATT_ERROR_INVALID_OFFSET;
685         }
686         instance->measurement_client_configuration_descriptor_notify = little_endian_read_16(buffer, 0);
687         instance->con_handle = con_handle;
688         log_info("cycling_power_service_write_callback: measurement enabled %d", instance->measurement_client_configuration_descriptor_notify);
689         return 0;
690     }
691 
692     if (attribute_handle == instance->measurement_server_configuration_descriptor_handle){
693         if (buffer_size < 2){
694             return ATT_ERROR_INVALID_OFFSET;
695         }
696         instance->measurement_server_configuration_descriptor_broadcast = little_endian_read_16(buffer, 0);
697         instance->con_handle = con_handle;
698         uint8_t event[5];
699         int index = 0;
700         event[index++] = HCI_EVENT_GATTSERVICE_META;
701         event[index++] = sizeof(event) - 2;
702 
703         if (instance->measurement_server_configuration_descriptor_broadcast){
704             event[index++] = GATTSERVICE_SUBEVENT_CYCLING_POWER_BROADCAST_START;
705             log_info("cycling_power_service_write_callback: start broadcast");
706         } else {
707             event[index++] = GATTSERVICE_SUBEVENT_CYCLING_POWER_BROADCAST_STOP;
708             log_info("cycling_power_service_write_callback: stop broadcast");
709         }
710         little_endian_store_16(event, index, con_handle);
711         index += 2;
712         (*instance->calibration_callback)(HCI_EVENT_PACKET, 0, event, sizeof(event));
713         return 0;
714     }
715 
716     if (attribute_handle == instance->vector_client_configuration_descriptor_handle){
717         if (buffer_size < 2){
718             return ATT_ERROR_INVALID_OFFSET;
719         }
720         instance->con_handle = con_handle;
721 
722 #ifdef ENABLE_ATT_DELAYED_RESPONSE
723         switch (instance->con_interval_status){
724             case CP_CONNECTION_INTERVAL_STATUS_REJECTED:
725                 return CYCLING_POWER_ERROR_CODE_INAPPROPRIATE_CONNECTION_PARAMETERS;
726 
727             case CP_CONNECTION_INTERVAL_STATUS_ACCEPTED:
728             case CP_CONNECTION_INTERVAL_STATUS_RECEIVED:
729                 if (instance->con_interval > instance->con_interval_max || instance->con_interval < instance->con_interval_min){
730                     instance->con_interval_status = CP_CONNECTION_INTERVAL_STATUS_W4_L2CAP_RESPONSE;
731                     gap_request_connection_parameter_update(instance->con_handle, instance->con_interval_min, instance->con_interval_max, 4, 100);    // 15 ms, 4, 1s
732                     return ATT_ERROR_WRITE_RESPONSE_PENDING;
733                 }
734                 instance->vector_client_configuration_descriptor_notify = little_endian_read_16(buffer, 0);
735                 return 0;
736             default:
737                 return ATT_ERROR_WRITE_RESPONSE_PENDING;
738 
739         }
740 #endif
741     }
742 
743     if (attribute_handle == instance->control_point_client_configuration_descriptor_handle){
744         if (buffer_size < 2){
745             return ATT_ERROR_INVALID_OFFSET;
746         }
747         instance->control_point_client_configuration_descriptor_indicate = little_endian_read_16(buffer, 0);
748         instance->con_handle = con_handle;
749         log_info("cycling_power_service_write_callback: indication enabled %d", instance->control_point_client_configuration_descriptor_indicate);
750         return 0;
751     }
752 
753     if (attribute_handle == instance->feature_value_handle){
754         if (buffer_size < 4){
755             return ATT_ERROR_INVALID_OFFSET;
756         }
757         instance->feature_flags = little_endian_read_32(buffer, 0);
758         return 0;
759     }
760 
761     if (attribute_handle == instance->control_point_value_handle){
762         if (instance->control_point_client_configuration_descriptor_indicate == 0) return CYCLING_POWER_ERROR_CODE_CCC_DESCRIPTOR_IMPROPERLY_CONFIGURED;
763         if (instance->w4_indication_complete != 0){
764             return CYCLING_POWER_ERROR_CODE_PROCEDURE_ALREADY_IN_PROGRESS;
765         }
766         int pos = 0;
767         instance->request_opcode = (cycling_power_opcode_t) buffer[pos++];
768         instance->response_value = CP_RESPONSE_VALUE_OP_CODE_NOT_SUPPORTED;
769 
770         switch (instance->request_opcode){
771             case CP_OPCODE_SET_CUMULATIVE_VALUE:
772                 if (!has_feature(CP_FEATURE_FLAG_WHEEL_REVOLUTION_DATA_SUPPORTED)) break;
773                 instance->cumulative_wheel_revolutions = little_endian_read_32(buffer, pos);
774                 instance->response_value = CP_RESPONSE_VALUE_SUCCESS;
775                 break;
776 
777             case CP_OPCODE_REQUEST_SUPPORTED_SENSOR_LOCATIONS:
778                 if (!has_feature(CP_FEATURE_FLAG_MULTIPLE_SENSOR_LOCATIONS_SUPPORTED)) break;
779                 instance->response_value = CP_RESPONSE_VALUE_SUCCESS;
780                 break;
781 
782             case CP_OPCODE_UPDATE_SENSOR_LOCATION:
783                 if (!has_feature(CP_FEATURE_FLAG_MULTIPLE_SENSOR_LOCATIONS_SUPPORTED)) break;
784                 location = (cycling_power_sensor_location_t) buffer[pos];
785                 instance->response_value = CP_RESPONSE_VALUE_INVALID_PARAMETER;
786                 for (i=0; i<instance->num_supported_sensor_locations; i++){
787                     if (instance->supported_sensor_locations[i] == location){
788                         instance->sensor_location = location;
789                         instance->response_value = CP_RESPONSE_VALUE_SUCCESS;
790                         break;
791                     }
792                 }
793                 break;
794 
795             case CP_OPCODE_REQUEST_CRANK_LENGTH:
796                 if (!has_feature(CP_FEATURE_FLAG_CRANK_LENGTH_ADJUSTMENT_SUPPORTED)) break;
797                 instance->response_value = CP_RESPONSE_VALUE_SUCCESS;
798                 break;
799             case CP_OPCODE_SET_CRANK_LENGTH:
800                 if (!has_feature(CP_FEATURE_FLAG_CRANK_LENGTH_ADJUSTMENT_SUPPORTED)) break;
801                 instance->crank_length_mm = little_endian_read_16(buffer, pos);
802                 instance->response_value = CP_RESPONSE_VALUE_SUCCESS;
803                 break;
804 
805             case CP_OPCODE_REQUEST_CHAIN_LENGTH:
806                 if (!has_feature(CP_FEATURE_FLAG_CHAIN_LENGTH_ADJUSTMENT_SUPPORTED)) break;
807                 instance->response_value = CP_RESPONSE_VALUE_SUCCESS;
808                 break;
809             case CP_OPCODE_SET_CHAIN_LENGTH:
810                 if (!has_feature(CP_FEATURE_FLAG_CHAIN_LENGTH_ADJUSTMENT_SUPPORTED)) break;
811                 instance->chain_length_mm = little_endian_read_16(buffer, pos);
812                 instance->response_value = CP_RESPONSE_VALUE_SUCCESS;
813                 break;
814 
815             case CP_OPCODE_REQUEST_CHAIN_WEIGHT:
816                 if (!has_feature(CP_FEATURE_FLAG_CHAIN_WEIGHT_ADJUSTMENT_SUPPORTED)) break;
817                 instance->response_value = CP_RESPONSE_VALUE_SUCCESS;
818                 break;
819             case CP_OPCODE_SET_CHAIN_WEIGHT:
820                 if (!has_feature(CP_FEATURE_FLAG_CHAIN_WEIGHT_ADJUSTMENT_SUPPORTED)) break;
821                 instance->chain_weight_g = little_endian_read_16(buffer, pos);
822                 instance->response_value = CP_RESPONSE_VALUE_SUCCESS;
823                 break;
824 
825             case CP_OPCODE_REQUEST_SPAN_LENGTH:
826                 if (!has_feature(CP_FEATURE_FLAG_SPAN_LENGTH_ADJUSTMENT_SUPPORTED)) break;
827                 instance->response_value = CP_RESPONSE_VALUE_SUCCESS;
828                 break;
829             case CP_OPCODE_SET_SPAN_LENGTH:
830                 if (!has_feature(CP_FEATURE_FLAG_SPAN_LENGTH_ADJUSTMENT_SUPPORTED)) break;
831                 instance->span_length_mm = little_endian_read_16(buffer, pos);
832                 instance->response_value = CP_RESPONSE_VALUE_SUCCESS;
833                 break;
834 
835             case CP_OPCODE_REQUEST_FACTORY_CALIBRATION_DATE:
836                 if (!has_feature(CP_FEATURE_FLAG_FACTORY_CALIBRATION_DATE_SUPPORTED)) break;
837                 instance->response_value = CP_RESPONSE_VALUE_SUCCESS;
838                 break;
839 
840             case CP_OPCODE_REQUEST_SAMPLING_RATE:
841                 if (!instance->vector_value_handle) break;
842                 instance->response_value = CP_RESPONSE_VALUE_SUCCESS;
843                 break;
844 
845             case CP_OPCODE_START_OFFSET_COMPENSATION:
846             case CP_OPCODE_START_ENHANCED_OFFSET_COMPENSATION:
847                 if (!has_feature(CP_FEATURE_FLAG_OFFSET_COMPENSATION_SUPPORTED)){
848                     instance->response_value = CP_RESPONSE_VALUE_INVALID_PARAMETER;
849                     break;
850                 }
851                 if (has_feature(CP_FEATURE_FLAG_EXTREME_MAGNITUDES_SUPPORTED) &&
852                         ((has_feature(CP_FEATURE_FLAG_SENSOR_MEASUREMENT_CONTEXT) == CP_SENSOR_MEASUREMENT_CONTEXT_FORCE) ||
853                          (has_feature(CP_FEATURE_FLAG_SENSOR_MEASUREMENT_CONTEXT) == CP_SENSOR_MEASUREMENT_CONTEXT_TORQUE))
854                 ){
855                     // printf("start offset compensation procedure, enhanced %d\n", (instance->request_opcode == CP_OPCODE_START_ENHANCED_OFFSET_COMPENSATION));
856                     uint8_t event[7];
857                     int index = 0;
858                     event[index++] = HCI_EVENT_GATTSERVICE_META;
859                     event[index++] = sizeof(event) - 2;
860                     event[index++] = GATTSERVICE_SUBEVENT_CYCLING_POWER_START_CALIBRATION;
861                     little_endian_store_16(event, index, con_handle);
862                     index += 2;
863                     event[index++] = has_feature(CP_FEATURE_FLAG_SENSOR_MEASUREMENT_CONTEXT) == CP_SENSOR_MEASUREMENT_CONTEXT_TORQUE;
864                     event[index++] = (instance->request_opcode == CP_OPCODE_START_ENHANCED_OFFSET_COMPENSATION);
865                     instance->response_value = CP_RESPONSE_VALUE_W4_VALUE_AVAILABLE;
866                     (*instance->calibration_callback)(HCI_EVENT_PACKET, 0, event, sizeof(event));
867                     return 0;
868                 }
869                 instance->current_force_magnitude_newton = 0xffff;
870                 instance->current_torque_magnitude_newton_m = 0xffff;
871                 break;
872 
873             case CP_OPCODE_MASK_CYCLING_POWER_MEASUREMENT_CHARACTERISTIC_CONTENT:{
874                 if (!has_feature(CP_FEATURE_FLAG_CYCLING_POWER_MEASUREMENT_CHARACTERISTIC_CONTENT_MASKING_SUPPORTED)) break;
875                 uint16_t mask_bitmap = little_endian_read_16(buffer, pos);
876                 uint16_t masked_measurement_flags = instance->default_measurement_flags;
877                 uint16_t index = 0;
878 
879                 for (i = 0; i < CP_MASK_BIT_RESERVED; i++){
880                     uint8_t clear_bit = mask_bitmap & (1 << i) ? 1 : 0;
881 
882                     masked_measurement_flags &= ~(clear_bit << index);
883                     index++;
884                     // following measurement flags have additional flag
885                     switch ((cycling_power_mask_bit_t)i){
886                         case CP_MASK_BIT_PEDAL_POWER_BALANCE:
887                         case CP_MASK_BIT_ACCUMULATED_TORQUE:
888                         case CP_MASK_BIT_EXTREME_MAGNITUDES:
889                             masked_measurement_flags &= ~(clear_bit << index);
890                             index++;
891                             break;
892                         default:
893                             break;
894                     }
895                 }
896                 instance->masked_measurement_flags = masked_measurement_flags;
897                 instance->response_value = CP_RESPONSE_VALUE_SUCCESS;
898                 break;
899             }
900             default:
901                 break;
902         }
903 
904         if (instance->control_point_client_configuration_descriptor_indicate){
905             instance->control_point_indicate_callback.callback = &cycling_power_service_response_can_send_now;
906             instance->control_point_indicate_callback.context  = (void*) instance;
907             att_server_register_can_send_now_callback(&instance->control_point_indicate_callback, instance->con_handle);
908         }
909         return 0;
910     }
911     return 0;
912 }
913 
914 static void packet_handler(uint8_t packet_type, uint16_t channel, uint8_t *packet, uint16_t size){
915     UNUSED(channel);
916     UNUSED(size);
917     cycling_power_t * instance = &cycling_power;
918     uint8_t event_type = hci_event_packet_get_type(packet);
919     uint16_t con_handle;
920 
921     if (packet_type != HCI_EVENT_PACKET) return;
922     switch (event_type){
923         case HCI_EVENT_LE_META:
924             switch (hci_event_le_meta_get_subevent_code(packet)){
925                 case HCI_SUBEVENT_LE_CONNECTION_COMPLETE:
926                     instance->con_handle = hci_subevent_le_connection_complete_get_connection_handle(packet);
927                     // print connection parameters (without using float operations)
928                     instance->con_interval = hci_subevent_le_connection_complete_get_conn_interval(packet);
929                     // printf("Initial Connection Interval: %u, %u.%02u ms\n", instance->con_interval, instance->con_interval * 125 / 100, 25 * (instance->con_interval & 3));
930                     // printf("Initial Connection Latency: %u\n", hci_subevent_le_connection_complete_get_conn_latency(packet));
931                     instance->con_interval_status = CP_CONNECTION_INTERVAL_STATUS_RECEIVED;
932                     break;
933                 case HCI_SUBEVENT_LE_CONNECTION_UPDATE_COMPLETE:
934                     if (instance->con_interval_status != CP_CONNECTION_INTERVAL_STATUS_W4_UPDATE) return;
935 
936                     if (instance->con_interval > instance->con_interval_max || instance->con_interval < instance->con_interval_min){
937                         instance->con_interval = hci_subevent_le_connection_update_complete_get_conn_interval(packet);
938                         // printf("Updated Connection Interval: %u, %u.%02u ms\n", instance->con_interval, instance->con_interval * 125 / 100, 25 * (instance->con_interval & 3));
939                         // printf("Updated Connection Latency: %u\n", hci_subevent_le_connection_update_complete_get_conn_latency(packet));
940                         instance->con_interval_status = CP_CONNECTION_INTERVAL_STATUS_ACCEPTED;
941                     } else {
942                         instance->con_interval_status = CP_CONNECTION_INTERVAL_STATUS_REJECTED;
943                     }
944                     att_server_response_ready(l2cap_event_connection_parameter_update_response_get_handle(packet));
945                     break;
946                 default:
947                     break;
948             }
949             break;
950         case L2CAP_EVENT_CONNECTION_PARAMETER_UPDATE_RESPONSE:
951             if (instance->con_interval_status != CP_CONNECTION_INTERVAL_STATUS_W4_L2CAP_RESPONSE) return;
952 
953             // printf("L2CAP Connection Parameter Update Complete, response: %x\n", l2cap_event_connection_parameter_update_response_get_result(packet));
954             if (l2cap_event_connection_parameter_update_response_get_result(packet) == ERROR_CODE_SUCCESS){
955                 instance->con_interval_status = CP_CONNECTION_INTERVAL_STATUS_W4_UPDATE;
956             } else {
957                 instance->con_interval_status = CP_CONNECTION_INTERVAL_STATUS_REJECTED;
958                 att_server_response_ready(l2cap_event_connection_parameter_update_response_get_handle(packet));
959             }
960             break;
961 
962         case HCI_EVENT_DISCONNECTION_COMPLETE:{
963             if (!instance) return;
964             con_handle = hci_event_disconnection_complete_get_connection_handle(packet);
965             if (con_handle == HCI_CON_HANDLE_INVALID) return;
966 
967             instance->masked_measurement_flags = CYCLING_POWER_MEASUREMENT_FLAGS_CLEARED;
968             instance->w4_indication_complete = 0;
969 
970             uint8_t event[5];
971             int index = 0;
972             event[index++] = HCI_EVENT_GATTSERVICE_META;
973             event[index++] = sizeof(event) - 2;
974 
975             event[index++] = GATTSERVICE_SUBEVENT_CYCLING_POWER_BROADCAST_STOP;
976             little_endian_store_16(event, index, con_handle);
977             index += 2;
978             (*instance->calibration_callback)(HCI_EVENT_PACKET, 0, event, sizeof(event));
979 
980             break;
981         }
982         case ATT_EVENT_HANDLE_VALUE_INDICATION_COMPLETE:
983             instance->w4_indication_complete = 0;
984             break;
985         default:
986             break;
987      }
988 }
989 
990 void cycling_power_service_server_init(uint32_t feature_flags,
991     cycling_power_pedal_power_balance_reference_t reference, cycling_power_torque_source_t torque_source,
992     cycling_power_sensor_location_t * supported_sensor_locations, uint16_t num_supported_sensor_locations,
993     cycling_power_sensor_location_t   current_sensor_location){
994 
995     cycling_power_t * instance = &cycling_power;
996     // TODO: remove hardcoded initialization
997     instance->con_interval_min = 6;
998     instance->con_interval_max = 6;
999     instance->con_interval_status = CP_CONNECTION_INTERVAL_STATUS_NONE;
1000     instance->w4_indication_complete = 0;
1001     hci_event_callback_registration.callback = &packet_handler;
1002     hci_add_event_handler(&hci_event_callback_registration);
1003     l2cap_register_packet_handler(&packet_handler);
1004 
1005     instance->sensor_location = current_sensor_location;
1006     instance->num_supported_sensor_locations = 0;
1007     if (supported_sensor_locations != NULL){
1008         instance->num_supported_sensor_locations = num_supported_sensor_locations;
1009         instance->supported_sensor_locations = supported_sensor_locations;
1010     }
1011 
1012     instance->feature_flags = feature_flags;
1013     instance->default_measurement_flags = CYCLING_POWER_MEASUREMENT_FLAGS_CLEARED;
1014     instance->masked_measurement_flags  = CYCLING_POWER_MEASUREMENT_FLAGS_CLEARED;
1015     instance->pedal_power_balance_reference = reference;
1016     instance->torque_source = torque_source;
1017 
1018     // get service handle range
1019     uint16_t start_handle = 0;
1020     uint16_t end_handle   = 0xffff;
1021     int service_found = gatt_server_get_get_handle_range_for_service_with_uuid16(ORG_BLUETOOTH_SERVICE_CYCLING_POWER, &start_handle, &end_handle);
1022     if (!service_found){
1023         log_error("no service found\n");
1024         return;
1025     }
1026     // get CP Mesurement characteristic value handle and client configuration handle
1027     instance->measurement_value_handle = gatt_server_get_value_handle_for_characteristic_with_uuid16(start_handle, end_handle, ORG_BLUETOOTH_CHARACTERISTIC_CYCLING_POWER_MEASUREMENT);
1028     instance->measurement_client_configuration_descriptor_handle = gatt_server_get_client_configuration_handle_for_characteristic_with_uuid16(start_handle, end_handle, ORG_BLUETOOTH_CHARACTERISTIC_CYCLING_POWER_MEASUREMENT);
1029     instance->measurement_server_configuration_descriptor_handle = gatt_server_get_server_configuration_handle_for_characteristic_with_uuid16(start_handle, end_handle, ORG_BLUETOOTH_CHARACTERISTIC_CYCLING_POWER_MEASUREMENT);
1030 
1031     // get CP Feature characteristic value handle and client configuration handle
1032     instance->feature_value_handle = gatt_server_get_value_handle_for_characteristic_with_uuid16(start_handle, end_handle, ORG_BLUETOOTH_CHARACTERISTIC_CYCLING_POWER_FEATURE);
1033     // get CP Sensor Location characteristic value handle and client configuration handle
1034     instance->sensor_location_value_handle = gatt_server_get_value_handle_for_characteristic_with_uuid16(start_handle, end_handle, ORG_BLUETOOTH_CHARACTERISTIC_SENSOR_LOCATION);
1035 
1036     // get CP Vector characteristic value handle and client configuration handle
1037     instance->vector_value_handle = gatt_server_get_value_handle_for_characteristic_with_uuid16(start_handle, end_handle, ORG_BLUETOOTH_CHARACTERISTIC_CYCLING_POWER_VECTOR);
1038     instance->vector_client_configuration_descriptor_handle = gatt_server_get_client_configuration_handle_for_characteristic_with_uuid16(start_handle, end_handle, ORG_BLUETOOTH_CHARACTERISTIC_CYCLING_POWER_VECTOR);
1039 
1040     // get Body Sensor Location characteristic value handle and client configuration handle
1041     instance->sensor_location_value_handle = gatt_server_get_value_handle_for_characteristic_with_uuid16(start_handle, end_handle, ORG_BLUETOOTH_CHARACTERISTIC_SENSOR_LOCATION);
1042 
1043     // get SP Control Point characteristic value handle and client configuration handle
1044     instance->control_point_value_handle = gatt_server_get_value_handle_for_characteristic_with_uuid16(start_handle, end_handle, ORG_BLUETOOTH_CHARACTERISTIC_CYCLING_POWER_CONTROL_POINT);
1045     instance->control_point_client_configuration_descriptor_handle = gatt_server_get_client_configuration_handle_for_characteristic_with_uuid16(start_handle, end_handle, ORG_BLUETOOTH_CHARACTERISTIC_CYCLING_POWER_CONTROL_POINT);
1046 
1047     log_info("Measurement     value handle 0x%02x", instance->measurement_value_handle);
1048     log_info("M. Client Cfg   value handle 0x%02x", instance->measurement_client_configuration_descriptor_handle);
1049     log_info("M. Server Cfg   value handle 0x%02x", instance->measurement_server_configuration_descriptor_handle);
1050 
1051     log_info("Feature         value handle 0x%02x", instance->feature_value_handle);
1052     log_info("Sensor location value handle 0x%02x", instance->sensor_location_value_handle);
1053 
1054     log_info("Vector          value handle 0x%02x", instance->vector_value_handle);
1055     log_info("Vector Cfg.     value handle 0x%02x", instance->vector_client_configuration_descriptor_handle);
1056 
1057     log_info("Control Point   value handle 0x%02x", instance->control_point_value_handle);
1058     log_info("Control P. Cfg. value handle 0x%02x", instance->control_point_client_configuration_descriptor_handle);
1059 
1060     cycling_power_service.start_handle   = start_handle;
1061     cycling_power_service.end_handle     = end_handle;
1062     cycling_power_service.read_callback  = &cycling_power_service_read_callback;
1063     cycling_power_service.write_callback = &cycling_power_service_write_callback;
1064     cycling_power_service.packet_handler = &packet_handler;
1065     att_server_register_service_handler(&cycling_power_service);
1066 }
1067 
1068 
1069 void cycling_power_service_server_add_torque(int16_t torque_m){
1070     cycling_power_t * instance = &cycling_power;
1071     instance->accumulated_torque_m += torque_m;
1072 }
1073 
1074 void cycling_power_service_server_add_wheel_revolution(int32_t wheel_revolution, uint16_t wheel_event_time_s){
1075     cycling_power_t * instance = &cycling_power;
1076     instance->last_wheel_event_time_s = wheel_event_time_s;
1077     if (wheel_revolution < 0){
1078         if (instance->cumulative_wheel_revolutions > -wheel_revolution){
1079             instance->cumulative_wheel_revolutions += wheel_revolution;
1080         } else {
1081             instance->cumulative_wheel_revolutions = 0;
1082         }
1083     } else {
1084         if (instance->cumulative_wheel_revolutions < 0xffffffff - wheel_revolution){
1085             instance->cumulative_wheel_revolutions += wheel_revolution;
1086         } else {
1087             instance->cumulative_wheel_revolutions = 0xffffffff;
1088         }
1089     }
1090 }
1091 
1092 void cycling_power_service_server_add_crank_revolution(uint16_t crank_revolution, uint16_t crank_event_time_s){
1093     cycling_power_t * instance = &cycling_power;
1094     instance->last_crank_event_time_s = crank_event_time_s;
1095     instance->cumulative_crank_revolutions += crank_revolution;
1096 }
1097 
1098 void cycling_power_service_add_energy(uint16_t energy_kJ){
1099     cycling_power_t * instance = &cycling_power;
1100     if (instance->accumulated_energy_kJ <= 0xffff - energy_kJ){
1101         instance->accumulated_energy_kJ += energy_kJ;
1102     } else {
1103         instance->accumulated_energy_kJ = 0xffff;
1104     }
1105     // printf("energy %d\n", instance->accumulated_energy_kJ);
1106 }
1107 
1108 void cycling_power_service_server_set_instantaneous_power(int16_t instantaneous_power_watt){
1109     cycling_power_t * instance = &cycling_power;
1110     instance->instantaneous_power_watt = instantaneous_power_watt;
1111 }
1112 
1113 void cycling_power_service_server_set_pedal_power_balance(uint8_t pedal_power_balance_percentage){
1114     cycling_power_t * instance = &cycling_power;
1115     instance->pedal_power_balance_percentage = pedal_power_balance_percentage;
1116 }
1117 
1118 void cycling_power_service_server_set_force_magnitude_values(int force_magnitude_count, int16_t * force_magnitude_newton_array){
1119     cycling_power_t * instance = &cycling_power;
1120     instance->force_magnitude_count = force_magnitude_count;
1121     instance->vector_instantaneous_force_magnitude_newton_array = force_magnitude_newton_array;
1122 }
1123 
1124 void cycling_power_service_server_set_torque_magnitude_values(int torque_magnitude_count, int16_t * torque_magnitude_newton_array){
1125     cycling_power_t * instance = &cycling_power;
1126     instance->torque_magnitude_count = torque_magnitude_count;
1127     instance->vector_instantaneous_torque_magnitude_newton_per_m_array = torque_magnitude_newton_array;
1128 }
1129 
1130 void cycling_power_service_server_set_first_crank_measurement_angle(uint16_t first_crank_measurement_angle_deg){
1131     cycling_power_t * instance = &cycling_power;
1132     instance->vector_first_crank_measurement_angle_deg = first_crank_measurement_angle_deg;
1133 }
1134 
1135 void cycling_power_service_server_set_instantaneous_measurement_direction(cycling_power_instantaneous_measurement_direction_t direction){
1136     cycling_power_t * instance = &cycling_power;
1137     instance->vector_instantaneous_measurement_direction = direction;
1138 }
1139 
1140 void cycling_power_service_server_set_force_magnitude(int16_t min_force_magnitude_newton, int16_t max_force_magnitude_newton){
1141     cycling_power_t * instance = &cycling_power;
1142     instance->minimum_force_magnitude_newton = min_force_magnitude_newton;
1143     instance->maximum_force_magnitude_newton = max_force_magnitude_newton;
1144 }
1145 
1146 void cycling_power_service_server_set_torque_magnitude(int16_t min_torque_magnitude_newton, int16_t max_torque_magnitude_newton){
1147     cycling_power_t * instance = &cycling_power;
1148     instance->minimum_torque_magnitude_newton_m = min_torque_magnitude_newton;
1149     instance->maximum_torque_magnitude_newton_m = max_torque_magnitude_newton;
1150 }
1151 
1152 void cycling_power_service_server_set_angle(uint16_t min_angle_deg, uint16_t max_angle_deg){
1153     cycling_power_t * instance = &cycling_power;
1154     instance->minimum_angle_deg = min_angle_deg;
1155     instance->maximum_angle_deg = max_angle_deg;
1156 }
1157 
1158 void cycling_power_service_server_set_top_dead_spot_angle(uint16_t top_dead_spot_angle_deg){
1159     cycling_power_t * instance = &cycling_power;
1160     instance->top_dead_spot_angle_deg = top_dead_spot_angle_deg;
1161 }
1162 
1163 void cycling_power_service_server_set_bottom_dead_spot_angle(uint16_t bottom_dead_spot_angle_deg){
1164     cycling_power_t * instance = &cycling_power;
1165     instance->bottom_dead_spot_angle_deg = bottom_dead_spot_angle_deg;
1166 }
1167 
1168 static int gatt_date_is_valid(gatt_date_time_t date){
1169     if (date.year != 0 && (date.year < 1582 || date.year > 9999)) return 0;
1170     if (date.month != 0 && date.month > 12) return 0;
1171     if (date.day != 0 && date.day > 31) return 0;
1172 
1173     if (date.hours > 23) return 0;
1174     if (date.minutes > 59) return 0;
1175     if (date.seconds > 59) return 0;
1176     return 1;
1177 }
1178 
1179 int cycling_power_service_server_set_factory_calibration_date(gatt_date_time_t date){
1180     if (!gatt_date_is_valid(date)) return 0;
1181 
1182     cycling_power_t * instance = &cycling_power;
1183     instance->factory_calibration_date = date;
1184     return 1;
1185 }
1186 
1187 void cycling_power_service_server_set_sampling_rate(uint8_t sampling_rate_hz){
1188     cycling_power_t * instance = &cycling_power;
1189     instance->sampling_rate_hz = sampling_rate_hz;
1190 }
1191 
1192 
1193 void cycling_power_service_server_update_values(void){
1194     cycling_power_t * instance = &cycling_power;
1195 
1196     if (instance->measurement_server_configuration_descriptor_broadcast){
1197         instance->measurement_broadcast_callback.callback = &cycling_power_service_broadcast_can_send_now;
1198         instance->measurement_broadcast_callback.context  = (void*) instance;
1199         att_server_register_can_send_now_callback(&instance->measurement_broadcast_callback, instance->con_handle);
1200     }
1201 
1202     if (instance->measurement_client_configuration_descriptor_notify){
1203         instance->measurement_notify_callback.callback = &cycling_power_service_measurement_can_send_now;
1204         instance->measurement_notify_callback.context  = (void*) instance;
1205         att_server_register_can_send_now_callback(&instance->measurement_notify_callback, instance->con_handle);
1206     }
1207 
1208     if (instance->vector_client_configuration_descriptor_notify){
1209         instance->vector_notify_callback.callback = &cycling_power_service_vector_can_send_now;
1210         instance->vector_notify_callback.context  = (void*) instance;
1211         att_server_register_can_send_now_callback(&instance->vector_notify_callback, instance->con_handle);
1212     }
1213 }
1214 
1215 void cycling_power_service_server_packet_handler(btstack_packet_handler_t callback){
1216     if (callback == NULL){
1217         log_error("cycling_power_service_server_packet_handler called with NULL callback");
1218         return;
1219     }
1220     cycling_power_t * instance = &cycling_power;
1221     instance->calibration_callback = callback;
1222 }
1223 
1224 void cycling_power_server_calibration_done(cycling_power_sensor_measurement_context_t measurement_type, uint16_t calibrated_value){
1225     cycling_power_t * instance = &cycling_power;
1226     if (instance->response_value != CP_RESPONSE_VALUE_W4_VALUE_AVAILABLE){
1227         printf("cycling_power_server_calibration_done : CP_RESPONSE_VALUE_W4_VALUE_AVAILABLE con_handle 0x%02x\n", instance->con_handle);
1228         return;
1229     }
1230     instance->response_value = CP_RESPONSE_VALUE_SUCCESS;
1231 
1232     switch (measurement_type){
1233         case CP_SENSOR_MEASUREMENT_CONTEXT_FORCE:
1234             instance->current_force_magnitude_newton = calibrated_value;
1235             break;
1236         case CP_SENSOR_MEASUREMENT_CONTEXT_TORQUE:
1237             instance->current_torque_magnitude_newton_m = calibrated_value;
1238             break;
1239         default:
1240             instance->response_value = CP_RESPONSE_VALUE_INVALID_PARAMETER;
1241             break;
1242     }
1243 
1244     if (instance->response_value == CP_RESPONSE_VALUE_SUCCESS){
1245         switch (calibrated_value){
1246             case CP_CALIBRATION_STATUS_INCORRECT_CALIBRATION_POSITION:
1247             case CP_CALIBRATION_STATUS_MANUFACTURER_SPECIFIC_ERROR_FOLLOWS:
1248                 instance->response_value = CP_RESPONSE_VALUE_OPERATION_FAILED;
1249                 instance->response_value = CP_RESPONSE_VALUE_OPERATION_FAILED;
1250                 break;
1251             default:
1252                 break;
1253         }
1254     }
1255 
1256     if (instance->control_point_client_configuration_descriptor_indicate){
1257         instance->control_point_indicate_callback.callback = &cycling_power_service_response_can_send_now;
1258         instance->control_point_indicate_callback.context  = (void*) instance;
1259         att_server_register_can_send_now_callback(&instance->control_point_indicate_callback, instance->con_handle);
1260     }
1261 }
1262 
1263 void cycling_power_server_enhanced_calibration_done(cycling_power_sensor_measurement_context_t measurement_type,
1264                 uint16_t calibrated_value, uint16_t manufacturer_company_id,
1265                 uint8_t num_manufacturer_specific_data, uint8_t * manufacturer_specific_data){
1266     cycling_power_t * instance = &cycling_power;
1267     if (instance->response_value != CP_RESPONSE_VALUE_W4_VALUE_AVAILABLE) return;
1268     instance->response_value = CP_RESPONSE_VALUE_SUCCESS;
1269 
1270     switch (measurement_type){
1271         case CP_SENSOR_MEASUREMENT_CONTEXT_FORCE:
1272             instance->current_force_magnitude_newton = calibrated_value;
1273             break;
1274         case CP_SENSOR_MEASUREMENT_CONTEXT_TORQUE:
1275             instance->current_torque_magnitude_newton_m = calibrated_value;
1276             break;
1277         default:
1278             instance->response_value = CP_RESPONSE_VALUE_INVALID_PARAMETER;
1279             break;
1280     }
1281 
1282     if (instance->response_value == CP_RESPONSE_VALUE_SUCCESS){
1283         switch (calibrated_value){
1284             case CP_CALIBRATION_STATUS_INCORRECT_CALIBRATION_POSITION:
1285             case CP_CALIBRATION_STATUS_MANUFACTURER_SPECIFIC_ERROR_FOLLOWS:
1286                 instance->response_value = CP_RESPONSE_VALUE_OPERATION_FAILED;
1287                 instance->response_value = CP_RESPONSE_VALUE_OPERATION_FAILED;
1288                 break;
1289             default:
1290                 break;
1291         }
1292         instance->manufacturer_company_id = manufacturer_company_id;
1293         instance->num_manufacturer_specific_data = num_manufacturer_specific_data;
1294         instance->manufacturer_specific_data = manufacturer_specific_data;
1295     }
1296 
1297     if (instance->control_point_client_configuration_descriptor_indicate){
1298         instance->control_point_indicate_callback.callback = &cycling_power_service_response_can_send_now;
1299         instance->control_point_indicate_callback.context  = (void*) instance;
1300         att_server_register_can_send_now_callback(&instance->control_point_indicate_callback, instance->con_handle);
1301     }
1302 }
1303