xref: /btstack/src/ble/gatt-service/cycling_power_service_server.c (revision 42a2bbebe0f5cb756f37d635be1a160ee231a9a2)
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__ "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_W;
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_Nm;             // newton-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_N;
139     int16_t  minimum_force_magnitude_N;
140     int16_t  maximum_torque_magnitude_Nm;       // newton-meters, resolution 1/32
141     int16_t  minimum_torque_magnitude_Nm;       // newton-meters, resolution 1/32
142     // extreme angles
143     uint16_t maximum_angle_degree;                 // 12bit, degrees
144     uint16_t minimum_angle_degree;                 // 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_degree;
147     uint16_t bottom_dead_spot_angle_degree;            // 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     uint16_t  current_force_magnitude_N;
183     uint16_t  current_torque_magnitude_Nm;               // 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_degree;
193     int16_t  * vector_instantaneous_force_magnitude_N_array;           // newton
194     uint16_t force_magnitude_count;
195     int16_t  * vector_instantaneous_torque_magnitude_Nm_array;         // newton-meter, resolution 1/32
196     uint16_t 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 static btstack_packet_callback_registration_t l2cap_event_callback_registration;
222 
223 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){
224     UNUSED(con_handle);
225     UNUSED(attribute_handle);
226     UNUSED(offset);
227     cycling_power_t * instance = &cycling_power;
228 
229     if (attribute_handle == instance->measurement_client_configuration_descriptor_handle){
230         if (buffer && (buffer_size >= 2u)){
231             little_endian_store_16(buffer, 0, instance->measurement_client_configuration_descriptor_notify);
232         }
233         return 2;
234     }
235 
236     if (attribute_handle == instance->measurement_server_configuration_descriptor_handle){
237         if (buffer && (buffer_size >= 2u)){
238             little_endian_store_16(buffer, 0, instance->measurement_server_configuration_descriptor_broadcast);
239         }
240         return 2;
241     }
242 
243     if (attribute_handle == instance->vector_client_configuration_descriptor_handle){
244         if (buffer && (buffer_size >= 2u)){
245             little_endian_store_16(buffer, 0, instance->vector_client_configuration_descriptor_notify);
246         }
247         return 2;
248     }
249 
250     if (attribute_handle == instance->control_point_client_configuration_descriptor_handle){
251         if (buffer && (buffer_size >= 2u)){
252             little_endian_store_16(buffer, 0, instance->control_point_client_configuration_descriptor_indicate);
253         }
254         return 2;
255     }
256 
257     if (attribute_handle == instance->feature_value_handle){
258         if (buffer && (buffer_size >= 4u)){
259             little_endian_store_32(buffer, 0, instance->feature_flags);
260         }
261         return 4;
262     }
263 
264     if (attribute_handle == instance->sensor_location_value_handle){
265         if (buffer && (buffer_size >= 1u)){
266             buffer[0] = instance->sensor_location;
267         }
268         return 1;
269     }
270     return 0;
271 }
272 
273 static int has_feature(cycling_power_feature_flag_t feature){
274     cycling_power_t * instance = &cycling_power;
275     return (instance->feature_flags & (1u << feature)) != 0u;
276 }
277 
278 static int cycling_power_vector_instantaneous_measurement_direction(void){
279     cycling_power_t * instance = &cycling_power;
280     return instance->vector_instantaneous_measurement_direction;
281 }
282 
283 static uint16_t cycling_power_service_default_measurement_flags(void){
284     cycling_power_t * instance = &cycling_power;
285     uint16_t measurement_flags = 0;
286     uint8_t flag[] = {
287         (uint8_t) has_feature(CP_FEATURE_FLAG_PEDAL_POWER_BALANCE_SUPPORTED),
288         (uint8_t) has_feature(CP_FEATURE_FLAG_PEDAL_POWER_BALANCE_SUPPORTED) && instance->pedal_power_balance_reference,
289         (uint8_t) has_feature(CP_FEATURE_FLAG_ACCUMULATED_TORQUE_SUPPORTED),
290         (uint8_t) has_feature(CP_FEATURE_FLAG_ACCUMULATED_TORQUE_SUPPORTED) && instance->torque_source,
291         (uint8_t) has_feature(CP_FEATURE_FLAG_WHEEL_REVOLUTION_DATA_SUPPORTED),
292         (uint8_t) has_feature(CP_FEATURE_FLAG_CRANK_REVOLUTION_DATA_SUPPORTED),
293         (uint8_t) has_feature(CP_FEATURE_FLAG_EXTREME_MAGNITUDES_SUPPORTED) && (has_feature(CP_FEATURE_FLAG_SENSOR_MEASUREMENT_CONTEXT) == CP_SENSOR_MEASUREMENT_CONTEXT_FORCE),
294         (uint8_t) has_feature(CP_FEATURE_FLAG_EXTREME_MAGNITUDES_SUPPORTED) && (has_feature(CP_FEATURE_FLAG_SENSOR_MEASUREMENT_CONTEXT) == CP_SENSOR_MEASUREMENT_CONTEXT_TORQUE),
295         (uint8_t) has_feature(CP_FEATURE_FLAG_EXTREME_ANGLES_SUPPORTED),
296         (uint8_t) has_feature(CP_FEATURE_FLAG_TOP_AND_BOTTOM_DEAD_SPOT_ANGLE_SUPPORTED),
297         (uint8_t) has_feature(CP_FEATURE_FLAG_TOP_AND_BOTTOM_DEAD_SPOT_ANGLE_SUPPORTED),
298         (uint8_t) has_feature(CP_FEATURE_FLAG_ACCUMULATED_ENERGY_SUPPORTED),
299         (uint8_t) has_feature(CP_FEATURE_FLAG_OFFSET_COMPENSATION_INDICATOR_SUPPORTED)
300     };
301 
302     int i;
303     for (i = CP_MEASUREMENT_FLAG_PEDAL_POWER_BALANCE_PRESENT; i <= CP_MEASUREMENT_FLAG_OFFSET_COMPENSATION_INDICATOR; i++){
304         measurement_flags |= flag[i] << i;
305     }
306 
307     return measurement_flags;
308 }
309 
310 static uint16_t cycling_power_service_get_measurement_flags(cycling_power_t * instance){
311     if (!instance) return 0;
312     if (instance->masked_measurement_flags != CYCLING_POWER_MEASUREMENT_FLAGS_CLEARED){
313         return instance->masked_measurement_flags;
314     }
315     if (instance->default_measurement_flags == CYCLING_POWER_MEASUREMENT_FLAGS_CLEARED){
316         instance->default_measurement_flags = cycling_power_service_default_measurement_flags();
317     }
318     return instance->default_measurement_flags;
319 }
320 
321 
322 uint16_t cycling_power_service_measurement_flags(void){
323     cycling_power_t * instance = &cycling_power;
324     return cycling_power_service_get_measurement_flags(instance);
325 }
326 
327 uint8_t cycling_power_service_vector_flags(void){
328     uint8_t vector_flags = 0;
329     uint8_t flag[] = {
330         (uint8_t )has_feature(CP_FEATURE_FLAG_CRANK_REVOLUTION_DATA_SUPPORTED),
331         (uint8_t )has_feature(CP_FEATURE_FLAG_EXTREME_ANGLES_SUPPORTED),
332         (uint8_t )has_feature(CP_FEATURE_FLAG_EXTREME_MAGNITUDES_SUPPORTED) && (has_feature(CP_FEATURE_FLAG_SENSOR_MEASUREMENT_CONTEXT) == CP_SENSOR_MEASUREMENT_CONTEXT_FORCE),
333         (uint8_t )has_feature(CP_FEATURE_FLAG_EXTREME_MAGNITUDES_SUPPORTED) && (has_feature(CP_FEATURE_FLAG_SENSOR_MEASUREMENT_CONTEXT) == CP_SENSOR_MEASUREMENT_CONTEXT_TORQUE),
334         (uint8_t )has_feature(CP_FEATURE_FLAG_INSTANTANEOUS_MEASUREMENT_DIRECTION_SUPPORTED) && cycling_power_vector_instantaneous_measurement_direction()
335     };
336 
337     int i;
338     for (i = CP_VECTOR_FLAG_CRANK_REVOLUTION_DATA_PRESENT; i <= CP_VECTOR_FLAG_INSTANTANEOUS_MEASUREMENT_DIRECTION; i++){
339         vector_flags |= flag[i] << i;
340     }
341     return vector_flags;
342 }
343 
344 static void cycling_power_service_vector_can_send_now(void * context){
345     cycling_power_t * instance = (cycling_power_t *) context;
346     if (!instance){
347         log_error("cycling_power_service_measurement_can_send_now: instance is null");
348         return;
349     }
350     uint8_t value[50];
351     uint8_t vector_flags = cycling_power_service_vector_flags();
352     int pos = 0;
353 
354     value[pos++] = vector_flags;
355     int i;
356     for (i = CP_VECTOR_FLAG_CRANK_REVOLUTION_DATA_PRESENT; i <= CP_VECTOR_FLAG_INSTANTANEOUS_MEASUREMENT_DIRECTION; i++){
357         if ((vector_flags & (1u << i)) == 0u) continue;
358         switch ((cycling_power_vector_flag_t) i){
359             case CP_VECTOR_FLAG_CRANK_REVOLUTION_DATA_PRESENT:
360                 little_endian_store_16(value, pos, instance->cumulative_crank_revolutions);
361                 pos += 2;
362                 little_endian_store_16(value, pos, instance->last_crank_event_time_s);
363                 pos += 2;
364                 break;
365             case CP_VECTOR_FLAG_INSTANTANEOUS_FORCE_MAGNITUDE_ARRAY_PRESENT:{
366                 uint16_t att_mtu = att_server_get_mtu(instance->con_handle);
367                 uint16_t bytes_left = 0;
368                 if (att_mtu > (pos + 3u)){
369                     bytes_left = btstack_min(sizeof(value), att_mtu - 3u - pos);
370                 }
371                 while ((bytes_left > 2u) && instance->force_magnitude_count){
372                     little_endian_store_16(value, pos, instance->vector_instantaneous_force_magnitude_N_array[0]);
373                     pos += 2;
374                     bytes_left -= 2u;
375                     instance->vector_instantaneous_force_magnitude_N_array++;
376                     instance->force_magnitude_count--;
377                 }
378                 break;
379             }
380             case CP_VECTOR_FLAG_INSTANTANEOUS_TORQUE_MAGNITUDE_ARRAY_PRESENT:{
381                 uint16_t att_mtu = att_server_get_mtu(instance->con_handle);
382                 uint16_t bytes_left = 0;
383                 if (att_mtu > (pos + 3u)){
384                     bytes_left = btstack_min(sizeof(value), att_mtu - 3u - pos);
385                 }
386 
387                 while ((bytes_left > 2u) && instance->torque_magnitude_count){
388                     little_endian_store_16(value, pos, instance->vector_instantaneous_torque_magnitude_Nm_array[0]);
389                     pos += 2;
390                     bytes_left -= 2u;
391                     instance->vector_instantaneous_torque_magnitude_Nm_array++;
392                     instance->torque_magnitude_count--;
393                 }
394                 break;
395             }
396             case CP_VECTOR_FLAG_FIRST_CRANK_MEASUREMENT_ANGLE_PRESENT:
397                 little_endian_store_16(value, pos, instance->vector_first_crank_measurement_angle_degree);
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_Nm);
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_N);
458             pos += 2;
459             little_endian_store_16(value, pos, (uint16_t)instance->minimum_force_magnitude_N);
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_Nm);
464             pos += 2;
465             little_endian_store_16(value, pos, (uint16_t)instance->minimum_torque_magnitude_Nm);
466             pos += 2;
467             break;
468         case CP_MEASUREMENT_FLAG_EXTREME_ANGLES_PRESENT:
469             little_endian_store_24(value, pos, (instance->maximum_angle_degree << 12) | instance->minimum_angle_degree);
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_degree);
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_degree);
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 < 4u) return 0u;
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_W);
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 & (1u << flag_index)) == 0u) 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 * adv_buffer, uint16_t adv_size){
516     if (adv_size < 12u) return 0u;
517     cycling_power_t * instance =  &cycling_power;
518     int pos = 0;
519     // adv flags
520     adv_buffer[pos++] = 2;
521     adv_buffer[pos++] = BLUETOOTH_DATA_TYPE_FLAGS;
522     adv_buffer[pos++] = 0x4;
523 
524     // adv interval
525     adv_buffer[pos++] = 3;
526     adv_buffer[pos++] = BLUETOOTH_DATA_TYPE_ADVERTISING_INTERVAL;
527     little_endian_store_16(adv_buffer, pos, adv_interval);
528     pos += 2;
529     //
530     int value_len = cycling_power_store_measurement(instance, &adv_buffer[pos + 4], CYCLING_POWER_MAX_BROACAST_MSG_SIZE - (pos + 4));
531     adv_buffer[pos++] = 3 + value_len;
532     adv_buffer[pos++] = BLUETOOTH_DATA_TYPE_SERVICE_DATA_16_BIT_UUID;
533     little_endian_store_16(adv_buffer, 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     // use preprocessor instead of btstack_max to get compile-time constant
576 #if (CP_SENSOR_LOCATION_RESERVED > (CYCLING_POWER_MANUFACTURER_SPECIFIC_DATA_MAX_SIZE + 5))
577     #define MAX_RESPONSE_PAYLOAD CP_SENSOR_LOCATION_RESERVED
578 #else
579     #define MAX_RESPONSE_PAYLOAD (CYCLING_POWER_MANUFACTURER_SPECIFIC_DATA_MAX_SIZE + 5)
580 #endif
581 
582     uint8_t value[3 + MAX_RESPONSE_PAYLOAD];
583     int pos = 0;
584     value[pos++] = CP_OPCODE_RESPONSE_CODE;
585     value[pos++] = instance->request_opcode;
586     value[pos++] = instance->response_value;
587     if (instance->response_value == CP_RESPONSE_VALUE_SUCCESS){
588         switch (instance->request_opcode){
589             case CP_OPCODE_REQUEST_SUPPORTED_SENSOR_LOCATIONS:{
590                 int i;
591                 for (i=0; i<instance->num_supported_sensor_locations; i++){
592                     value[pos++] = instance->supported_sensor_locations[i];
593                 }
594                 break;
595             }
596             case CP_OPCODE_REQUEST_CRANK_LENGTH:
597                 little_endian_store_16(value, pos, instance->crank_length_mm);
598                 pos += 2;
599                 break;
600             case CP_OPCODE_REQUEST_CHAIN_LENGTH:
601                 little_endian_store_16(value, pos, instance->chain_length_mm);
602                 pos += 2;
603                 break;
604             case CP_OPCODE_REQUEST_CHAIN_WEIGHT:
605                 little_endian_store_16(value, pos, instance->chain_weight_g);
606                 pos += 2;
607                 break;
608             case CP_OPCODE_REQUEST_SPAN_LENGTH:
609                 little_endian_store_16(value, pos, instance->span_length_mm);
610                 pos += 2;
611                 break;
612             case CP_OPCODE_REQUEST_FACTORY_CALIBRATION_DATE:
613                 little_endian_store_16(value, pos, instance->factory_calibration_date.year);
614                 pos += 2;
615                 value[pos++] = instance->factory_calibration_date.month;
616                 value[pos++] = instance->factory_calibration_date.day;
617                 value[pos++] = instance->factory_calibration_date.hours;
618                 value[pos++] = instance->factory_calibration_date.minutes;
619                 value[pos++] = instance->factory_calibration_date.seconds;
620                 break;
621             case CP_OPCODE_REQUEST_SAMPLING_RATE:
622                 value[pos++] = instance->sampling_rate_Hz;
623                 break;
624             case CP_OPCODE_START_OFFSET_COMPENSATION:
625             case CP_OPCODE_START_ENHANCED_OFFSET_COMPENSATION:{
626                 uint16_t calibrated_value = 0xffff;
627                 if (has_feature(CP_FEATURE_FLAG_EXTREME_MAGNITUDES_SUPPORTED)){
628                     if (has_feature(CP_FEATURE_FLAG_SENSOR_MEASUREMENT_CONTEXT) == CP_SENSOR_MEASUREMENT_CONTEXT_FORCE) {
629                         calibrated_value = instance->current_force_magnitude_N;
630                     } else if (has_feature(CP_FEATURE_FLAG_SENSOR_MEASUREMENT_CONTEXT) == CP_SENSOR_MEASUREMENT_CONTEXT_TORQUE){
631                         calibrated_value = instance->current_torque_magnitude_Nm;
632                     }
633                 }
634 
635                 if (calibrated_value == CP_CALIBRATION_STATUS_INCORRECT_CALIBRATION_POSITION){
636                      value[pos++] = (uint8_t) calibrated_value;
637                      // do not include manufacturer ID and data
638                      break;
639                 } else if (calibrated_value == CP_CALIBRATION_STATUS_MANUFACTURER_SPECIFIC_ERROR_FOLLOWS){
640                     value[pos++] = (uint8_t) calibrated_value;
641                 } else {
642                     little_endian_store_16(value, pos, calibrated_value);
643                     pos += 2;
644                 }
645 
646                 if (instance->request_opcode == CP_OPCODE_START_OFFSET_COMPENSATION) break;
647                 little_endian_store_16(value, pos, instance->manufacturer_company_id);
648                 pos += 2;
649                 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);
650                 value[pos++] = data_len;
651                 (void)memcpy(&value[pos],
652                              instance->manufacturer_specific_data, data_len);
653                 pos += data_len;
654                 value[pos++] = 0;
655                 break;
656             }
657             case CP_OPCODE_MASK_CYCLING_POWER_MEASUREMENT_CHARACTERISTIC_CONTENT:
658                 break;
659             default:
660                 break;
661         }
662     }
663     uint8_t status = att_server_indicate(instance->con_handle, instance->control_point_value_handle, &value[0], pos);
664     if (status == ERROR_CODE_SUCCESS){
665         instance->w4_indication_complete = 1;
666         instance->request_opcode = CP_OPCODE_IDLE;
667     } else {
668         log_error("can_send_now failed 0x%2x", status);
669     }
670 }
671 
672 static void cycling_power_service_server_emit_start_calibration(const cycling_power_t *instance, bool enhanced) {
673 
674     cycling_power_sensor_measurement_context_t measurement_type =
675             has_feature(CP_FEATURE_FLAG_SENSOR_MEASUREMENT_CONTEXT) ? CP_SENSOR_MEASUREMENT_CONTEXT_TORQUE : CP_SENSOR_MEASUREMENT_CONTEXT_FORCE;
676 
677     uint8_t event[7];
678     int index = 0;
679     event[index++] = HCI_EVENT_GATTSERVICE_META;
680     event[index++] = sizeof(event) - 2u;
681     event[index++] = GATTSERVICE_SUBEVENT_CYCLING_POWER_START_CALIBRATION;
682     little_endian_store_16(event, index, instance->con_handle);
683     index += 2;
684     event[index++] = (uint8_t) measurement_type;
685     event[index++] = enhanced ? 1 : 0;
686     (*instance->calibration_callback)(HCI_EVENT_PACKET, 0, event, sizeof(event));
687 }
688 
689 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){
690     UNUSED(con_handle);
691     UNUSED(offset);
692     UNUSED(buffer_size);
693     int i;
694     cycling_power_sensor_location_t location;
695     cycling_power_t * instance = &cycling_power;
696 
697     if (transaction_mode != ATT_TRANSACTION_MODE_NONE){
698         return 0;
699     }
700 
701     if (attribute_handle == instance->measurement_client_configuration_descriptor_handle){
702         if (buffer_size < 2u){
703             return ATT_ERROR_INVALID_OFFSET;
704         }
705         instance->measurement_client_configuration_descriptor_notify = little_endian_read_16(buffer, 0);
706         instance->con_handle = con_handle;
707         log_info("cycling_power_service_write_callback: measurement enabled %d", instance->measurement_client_configuration_descriptor_notify);
708         return 0;
709     }
710 
711     if (attribute_handle == instance->measurement_server_configuration_descriptor_handle){
712         if (buffer_size < 2u){
713             return ATT_ERROR_INVALID_OFFSET;
714         }
715         instance->measurement_server_configuration_descriptor_broadcast = little_endian_read_16(buffer, 0);
716         instance->con_handle = con_handle;
717         uint8_t event[5];
718         int index = 0;
719         event[index++] = HCI_EVENT_GATTSERVICE_META;
720         event[index++] = sizeof(event) - 2u;
721 
722         if (instance->measurement_server_configuration_descriptor_broadcast){
723             event[index++] = GATTSERVICE_SUBEVENT_CYCLING_POWER_BROADCAST_START;
724             log_info("cycling_power_service_write_callback: start broadcast");
725         } else {
726             event[index++] = GATTSERVICE_SUBEVENT_CYCLING_POWER_BROADCAST_STOP;
727             log_info("cycling_power_service_write_callback: stop broadcast");
728         }
729         little_endian_store_16(event, index, con_handle);
730         index += 2;
731         (*instance->calibration_callback)(HCI_EVENT_PACKET, 0, event, sizeof(event));
732         return 0;
733     }
734 
735     if (attribute_handle == instance->vector_client_configuration_descriptor_handle){
736         if (buffer_size < 2u){
737             return ATT_ERROR_INVALID_OFFSET;
738         }
739         instance->con_handle = con_handle;
740 
741 #ifdef ENABLE_ATT_DELAYED_RESPONSE
742         switch (instance->con_interval_status){
743             case CP_CONNECTION_INTERVAL_STATUS_REJECTED:
744                 return CYCLING_POWER_ERROR_CODE_INAPPROPRIATE_CONNECTION_PARAMETERS;
745 
746             case CP_CONNECTION_INTERVAL_STATUS_ACCEPTED:
747             case CP_CONNECTION_INTERVAL_STATUS_RECEIVED:
748                 if ((instance->con_interval > instance->con_interval_max) || (instance->con_interval < instance->con_interval_min)){
749                     instance->con_interval_status = CP_CONNECTION_INTERVAL_STATUS_W4_L2CAP_RESPONSE;
750                     gap_request_connection_parameter_update(instance->con_handle, instance->con_interval_min, instance->con_interval_max, 4, 100);    // 15 ms, 4, 1s
751                     return ATT_ERROR_WRITE_RESPONSE_PENDING;
752                 }
753                 instance->vector_client_configuration_descriptor_notify = little_endian_read_16(buffer, 0);
754                 return 0;
755             default:
756                 return ATT_ERROR_WRITE_RESPONSE_PENDING;
757 
758         }
759 #endif
760     }
761 
762     if (attribute_handle == instance->control_point_client_configuration_descriptor_handle){
763         if (buffer_size < 2u){
764             return ATT_ERROR_INVALID_OFFSET;
765         }
766         instance->control_point_client_configuration_descriptor_indicate = little_endian_read_16(buffer, 0);
767         instance->con_handle = con_handle;
768         log_info("cycling_power_service_write_callback: indication enabled %d", instance->control_point_client_configuration_descriptor_indicate);
769         return 0;
770     }
771 
772     if (attribute_handle == instance->feature_value_handle){
773         if (buffer_size < 4u){
774             return ATT_ERROR_INVALID_OFFSET;
775         }
776         instance->feature_flags = little_endian_read_32(buffer, 0);
777         return 0;
778     }
779 
780     if (attribute_handle == instance->control_point_value_handle){
781         if (instance->control_point_client_configuration_descriptor_indicate == 0u) return CYCLING_POWER_ERROR_CODE_CCC_DESCRIPTOR_IMPROPERLY_CONFIGURED;
782         if (instance->w4_indication_complete != 0u){
783             return CYCLING_POWER_ERROR_CODE_PROCEDURE_ALREADY_IN_PROGRESS;
784         }
785         int pos = 0;
786         instance->request_opcode = (cycling_power_opcode_t) buffer[pos++];
787         instance->response_value = CP_RESPONSE_VALUE_OP_CODE_NOT_SUPPORTED;
788 
789         switch (instance->request_opcode){
790             case CP_OPCODE_SET_CUMULATIVE_VALUE:
791                 if (!has_feature(CP_FEATURE_FLAG_WHEEL_REVOLUTION_DATA_SUPPORTED)) break;
792                 instance->cumulative_wheel_revolutions = little_endian_read_32(buffer, pos);
793                 instance->response_value = CP_RESPONSE_VALUE_SUCCESS;
794                 break;
795 
796             case CP_OPCODE_REQUEST_SUPPORTED_SENSOR_LOCATIONS:
797                 if (!has_feature(CP_FEATURE_FLAG_MULTIPLE_SENSOR_LOCATIONS_SUPPORTED)) break;
798                 instance->response_value = CP_RESPONSE_VALUE_SUCCESS;
799                 break;
800 
801             case CP_OPCODE_UPDATE_SENSOR_LOCATION:
802                 if (!has_feature(CP_FEATURE_FLAG_MULTIPLE_SENSOR_LOCATIONS_SUPPORTED)) break;
803                 location = (cycling_power_sensor_location_t) buffer[pos];
804                 instance->response_value = CP_RESPONSE_VALUE_INVALID_PARAMETER;
805                 for (i=0; i<instance->num_supported_sensor_locations; i++){
806                     if (instance->supported_sensor_locations[i] == location){
807                         instance->sensor_location = location;
808                         instance->response_value = CP_RESPONSE_VALUE_SUCCESS;
809                         break;
810                     }
811                 }
812                 break;
813 
814             case CP_OPCODE_REQUEST_CRANK_LENGTH:
815                 if (!has_feature(CP_FEATURE_FLAG_CRANK_LENGTH_ADJUSTMENT_SUPPORTED)) break;
816                 instance->response_value = CP_RESPONSE_VALUE_SUCCESS;
817                 break;
818             case CP_OPCODE_SET_CRANK_LENGTH:
819                 if (!has_feature(CP_FEATURE_FLAG_CRANK_LENGTH_ADJUSTMENT_SUPPORTED)) break;
820                 instance->crank_length_mm = little_endian_read_16(buffer, pos);
821                 instance->response_value = CP_RESPONSE_VALUE_SUCCESS;
822                 break;
823 
824             case CP_OPCODE_REQUEST_CHAIN_LENGTH:
825                 if (!has_feature(CP_FEATURE_FLAG_CHAIN_LENGTH_ADJUSTMENT_SUPPORTED)) break;
826                 instance->response_value = CP_RESPONSE_VALUE_SUCCESS;
827                 break;
828             case CP_OPCODE_SET_CHAIN_LENGTH:
829                 if (!has_feature(CP_FEATURE_FLAG_CHAIN_LENGTH_ADJUSTMENT_SUPPORTED)) break;
830                 instance->chain_length_mm = little_endian_read_16(buffer, pos);
831                 instance->response_value = CP_RESPONSE_VALUE_SUCCESS;
832                 break;
833 
834             case CP_OPCODE_REQUEST_CHAIN_WEIGHT:
835                 if (!has_feature(CP_FEATURE_FLAG_CHAIN_WEIGHT_ADJUSTMENT_SUPPORTED)) break;
836                 instance->response_value = CP_RESPONSE_VALUE_SUCCESS;
837                 break;
838             case CP_OPCODE_SET_CHAIN_WEIGHT:
839                 if (!has_feature(CP_FEATURE_FLAG_CHAIN_WEIGHT_ADJUSTMENT_SUPPORTED)) break;
840                 instance->chain_weight_g = little_endian_read_16(buffer, pos);
841                 instance->response_value = CP_RESPONSE_VALUE_SUCCESS;
842                 break;
843 
844             case CP_OPCODE_REQUEST_SPAN_LENGTH:
845                 if (!has_feature(CP_FEATURE_FLAG_SPAN_LENGTH_ADJUSTMENT_SUPPORTED)) break;
846                 instance->response_value = CP_RESPONSE_VALUE_SUCCESS;
847                 break;
848             case CP_OPCODE_SET_SPAN_LENGTH:
849                 if (!has_feature(CP_FEATURE_FLAG_SPAN_LENGTH_ADJUSTMENT_SUPPORTED)) break;
850                 instance->span_length_mm = little_endian_read_16(buffer, pos);
851                 instance->response_value = CP_RESPONSE_VALUE_SUCCESS;
852                 break;
853 
854             case CP_OPCODE_REQUEST_FACTORY_CALIBRATION_DATE:
855                 if (!has_feature(CP_FEATURE_FLAG_FACTORY_CALIBRATION_DATE_SUPPORTED)) break;
856                 instance->response_value = CP_RESPONSE_VALUE_SUCCESS;
857                 break;
858 
859             case CP_OPCODE_REQUEST_SAMPLING_RATE:
860                 if (!instance->vector_value_handle) break;
861                 instance->response_value = CP_RESPONSE_VALUE_SUCCESS;
862                 break;
863 
864             case CP_OPCODE_START_OFFSET_COMPENSATION:
865                 if (has_feature(CP_FEATURE_FLAG_OFFSET_COMPENSATION_SUPPORTED)){
866                     instance->response_value = CP_RESPONSE_VALUE_W4_VALUE_AVAILABLE;
867                     cycling_power_service_server_emit_start_calibration(instance, false);
868                 } else {
869                     instance->response_value = CP_RESPONSE_VALUE_INVALID_PARAMETER;
870                 }
871                 break;
872 
873             case CP_OPCODE_START_ENHANCED_OFFSET_COMPENSATION:
874                 if (has_feature(CP_FEATURE_FLAG_ENHANCED_OFFSET_COMPENSATION_SUPPORTED)){
875                     instance->response_value = CP_RESPONSE_VALUE_W4_VALUE_AVAILABLE;
876                     cycling_power_service_server_emit_start_calibration(instance, true);
877                 } else {
878                     instance->response_value = CP_RESPONSE_VALUE_INVALID_PARAMETER;
879                 }
880                 break;
881 
882             case CP_OPCODE_MASK_CYCLING_POWER_MEASUREMENT_CHARACTERISTIC_CONTENT:{
883                 if (!has_feature(CP_FEATURE_FLAG_CYCLING_POWER_MEASUREMENT_CHARACTERISTIC_CONTENT_MASKING_SUPPORTED)) break;
884                 uint16_t mask_bitmap = little_endian_read_16(buffer, pos);
885                 uint16_t masked_measurement_flags = instance->default_measurement_flags;
886                 uint16_t index = 0;
887 
888                 for (i = 0; i < CP_MASK_BIT_RESERVED; i++){
889                     uint8_t clear_bit = (mask_bitmap & (1u << i)) ? 1u : 0u;
890 
891                     masked_measurement_flags &= ~(clear_bit << index);
892                     index++;
893                     // following measurement flags have additional flag
894                     switch ((cycling_power_mask_bit_t)i){
895                         case CP_MASK_BIT_PEDAL_POWER_BALANCE:
896                         case CP_MASK_BIT_ACCUMULATED_TORQUE:
897                         case CP_MASK_BIT_EXTREME_MAGNITUDES:
898                             masked_measurement_flags &= ~(clear_bit << index);
899                             index++;
900                             break;
901                         default:
902                             break;
903                     }
904                 }
905                 instance->masked_measurement_flags = masked_measurement_flags;
906                 instance->response_value = CP_RESPONSE_VALUE_SUCCESS;
907                 break;
908             }
909             default:
910                 break;
911         }
912 
913         if (instance->control_point_client_configuration_descriptor_indicate){
914             instance->control_point_indicate_callback.callback = &cycling_power_service_response_can_send_now;
915             instance->control_point_indicate_callback.context  = (void*) instance;
916             att_server_register_can_send_now_callback(&instance->control_point_indicate_callback, instance->con_handle);
917         }
918         return 0;
919     }
920     return 0;
921 }
922 
923 static void packet_handler(uint8_t packet_type, uint16_t channel, uint8_t *packet, uint16_t size){
924     UNUSED(channel);
925     UNUSED(size);
926     cycling_power_t * instance = &cycling_power;
927     uint8_t event_type = hci_event_packet_get_type(packet);
928     uint16_t con_handle;
929 
930     if (packet_type != HCI_EVENT_PACKET) return;
931     switch (event_type){
932         case HCI_EVENT_META_GAP:
933             switch (hci_event_gap_meta_get_subevent_code(packet)) {
934                 case GAP_SUBEVENT_LE_CONNECTION_COMPLETE:
935                     instance->con_handle = gap_subevent_le_connection_complete_get_connection_handle(packet);
936                     // print connection parameters (without using float operations)
937                     instance->con_interval = gap_subevent_le_connection_complete_get_conn_interval(packet);
938                     instance->con_interval_status = CP_CONNECTION_INTERVAL_STATUS_RECEIVED;
939                     break;
940                 default:
941                     break;
942             }
943             break;
944         case HCI_EVENT_LE_META:
945             switch (hci_event_le_meta_get_subevent_code(packet)){
946 #ifdef ENABLE_ATT_DELAYED_RESPONSE
947                 case HCI_SUBEVENT_LE_CONNECTION_UPDATE_COMPLETE:
948                     if (instance->con_interval_status != CP_CONNECTION_INTERVAL_STATUS_W4_UPDATE) return;
949 
950                     if ((instance->con_interval > instance->con_interval_max) || (instance->con_interval < instance->con_interval_min)){
951                         instance->con_interval = hci_subevent_le_connection_update_complete_get_conn_interval(packet);
952                         instance->con_interval_status = CP_CONNECTION_INTERVAL_STATUS_ACCEPTED;
953                     } else {
954                         instance->con_interval_status = CP_CONNECTION_INTERVAL_STATUS_REJECTED;
955                     }
956                     att_server_response_ready(l2cap_event_connection_parameter_update_response_get_handle(packet));
957                     break;
958 #endif
959                 default:
960                     break;
961             }
962             break;
963 
964 #ifdef ENABLE_ATT_DELAYED_RESPONSE
965         case L2CAP_EVENT_CONNECTION_PARAMETER_UPDATE_RESPONSE:
966             if (instance->con_interval_status != CP_CONNECTION_INTERVAL_STATUS_W4_L2CAP_RESPONSE) return;
967 
968             if (l2cap_event_connection_parameter_update_response_get_result(packet) == ERROR_CODE_SUCCESS){
969                 instance->con_interval_status = CP_CONNECTION_INTERVAL_STATUS_W4_UPDATE;
970             } else {
971                 instance->con_interval_status = CP_CONNECTION_INTERVAL_STATUS_REJECTED;
972                 att_server_response_ready(l2cap_event_connection_parameter_update_response_get_handle(packet));
973             }
974             break;
975 #endif
976 
977         case HCI_EVENT_DISCONNECTION_COMPLETE:{
978             if (!instance) return;
979             con_handle = hci_event_disconnection_complete_get_connection_handle(packet);
980             if (con_handle == HCI_CON_HANDLE_INVALID) return;
981 
982             instance->masked_measurement_flags = CYCLING_POWER_MEASUREMENT_FLAGS_CLEARED;
983             instance->w4_indication_complete = 0;
984 
985             uint8_t event[5];
986             int index = 0;
987             event[index++] = HCI_EVENT_GATTSERVICE_META;
988             event[index++] = sizeof(event) - 2u;
989 
990             event[index++] = GATTSERVICE_SUBEVENT_CYCLING_POWER_BROADCAST_STOP;
991             little_endian_store_16(event, index, con_handle);
992             index += 2;
993             (*instance->calibration_callback)(HCI_EVENT_PACKET, 0, event, sizeof(event));
994 
995             break;
996         }
997         case ATT_EVENT_HANDLE_VALUE_INDICATION_COMPLETE:
998             instance->w4_indication_complete = 0;
999             break;
1000         default:
1001             break;
1002      }
1003 }
1004 
1005 void cycling_power_service_server_init(uint32_t feature_flags,
1006                                        cycling_power_pedal_power_balance_reference_t pedal_power_balance_reference, cycling_power_torque_source_t torque_source,
1007                                        cycling_power_sensor_location_t * supported_sensor_locations, uint16_t num_supported_sensor_locations,
1008                                        cycling_power_sensor_location_t   current_sensor_location){
1009 
1010     cycling_power_t * instance = &cycling_power;
1011     // TODO: remove hardcoded initialization
1012     instance->con_interval_min = 6;
1013     instance->con_interval_max = 6;
1014     instance->con_interval_status = CP_CONNECTION_INTERVAL_STATUS_NONE;
1015     instance->w4_indication_complete = 0;
1016 
1017     hci_event_callback_registration.callback = &packet_handler;
1018     hci_add_event_handler(&hci_event_callback_registration);
1019 
1020     l2cap_event_callback_registration.callback = &packet_handler;
1021     l2cap_add_event_handler(&l2cap_event_callback_registration);
1022 
1023     instance->sensor_location = current_sensor_location;
1024     instance->num_supported_sensor_locations = 0;
1025     if (supported_sensor_locations != NULL){
1026         instance->num_supported_sensor_locations = num_supported_sensor_locations;
1027         instance->supported_sensor_locations = supported_sensor_locations;
1028     }
1029 
1030     instance->feature_flags = feature_flags;
1031     instance->default_measurement_flags = CYCLING_POWER_MEASUREMENT_FLAGS_CLEARED;
1032     instance->masked_measurement_flags  = CYCLING_POWER_MEASUREMENT_FLAGS_CLEARED;
1033     instance->pedal_power_balance_reference = pedal_power_balance_reference;
1034     instance->torque_source = torque_source;
1035 
1036     // get service handle range
1037     uint16_t start_handle = 0;
1038     uint16_t end_handle   = 0xffff;
1039     int service_found = gatt_server_get_handle_range_for_service_with_uuid16(ORG_BLUETOOTH_SERVICE_CYCLING_POWER, &start_handle, &end_handle);
1040     btstack_assert(service_found != 0);
1041 	UNUSED(service_found);
1042 
1043     // get CP Mesurement characteristic value handle and client configuration handle
1044     instance->measurement_value_handle = gatt_server_get_value_handle_for_characteristic_with_uuid16(start_handle, end_handle, ORG_BLUETOOTH_CHARACTERISTIC_CYCLING_POWER_MEASUREMENT);
1045     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);
1046     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);
1047 
1048     // get CP Feature characteristic value handle and client configuration handle
1049     instance->feature_value_handle = gatt_server_get_value_handle_for_characteristic_with_uuid16(start_handle, end_handle, ORG_BLUETOOTH_CHARACTERISTIC_CYCLING_POWER_FEATURE);
1050     // get CP Sensor Location characteristic value handle and client configuration handle
1051     instance->sensor_location_value_handle = gatt_server_get_value_handle_for_characteristic_with_uuid16(start_handle, end_handle, ORG_BLUETOOTH_CHARACTERISTIC_SENSOR_LOCATION);
1052 
1053     // get CP Vector characteristic value handle and client configuration handle
1054     instance->vector_value_handle = gatt_server_get_value_handle_for_characteristic_with_uuid16(start_handle, end_handle, ORG_BLUETOOTH_CHARACTERISTIC_CYCLING_POWER_VECTOR);
1055     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);
1056 
1057     // get Body Sensor Location characteristic value handle and client configuration handle
1058     instance->sensor_location_value_handle = gatt_server_get_value_handle_for_characteristic_with_uuid16(start_handle, end_handle, ORG_BLUETOOTH_CHARACTERISTIC_SENSOR_LOCATION);
1059 
1060     // get SP Control Point characteristic value handle and client configuration handle
1061     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);
1062     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);
1063 
1064     log_info("Measurement     value handle 0x%02x", instance->measurement_value_handle);
1065     log_info("M. Client Cfg   value handle 0x%02x", instance->measurement_client_configuration_descriptor_handle);
1066     log_info("M. Server Cfg   value handle 0x%02x", instance->measurement_server_configuration_descriptor_handle);
1067 
1068     log_info("Feature         value handle 0x%02x", instance->feature_value_handle);
1069     log_info("Sensor location value handle 0x%02x", instance->sensor_location_value_handle);
1070 
1071     log_info("Vector          value handle 0x%02x", instance->vector_value_handle);
1072     log_info("Vector Cfg.     value handle 0x%02x", instance->vector_client_configuration_descriptor_handle);
1073 
1074     log_info("Control Point   value handle 0x%02x", instance->control_point_value_handle);
1075     log_info("Control P. Cfg. value handle 0x%02x", instance->control_point_client_configuration_descriptor_handle);
1076 
1077     cycling_power_service.start_handle   = start_handle;
1078     cycling_power_service.end_handle     = end_handle;
1079     cycling_power_service.read_callback  = &cycling_power_service_read_callback;
1080     cycling_power_service.write_callback = &cycling_power_service_write_callback;
1081     cycling_power_service.packet_handler = &packet_handler;
1082     att_server_register_service_handler(&cycling_power_service);
1083 }
1084 
1085 
1086 void cycling_power_service_server_add_torque(int16_t torque_Nm){
1087     cycling_power_t * instance = &cycling_power;
1088     instance->accumulated_torque_Nm += torque_Nm;
1089 }
1090 
1091 void cycling_power_service_server_add_wheel_revolution(int32_t wheel_revolution, uint16_t wheel_event_time_s){
1092     cycling_power_t * instance = &cycling_power;
1093     instance->last_wheel_event_time_s = wheel_event_time_s;
1094     if (wheel_revolution < 0){
1095         uint32_t wheel_revolution_to_subtract = (uint32_t) (-wheel_revolution);
1096         if (instance->cumulative_wheel_revolutions > wheel_revolution_to_subtract){
1097             instance->cumulative_wheel_revolutions -= wheel_revolution_to_subtract;
1098         } else {
1099             instance->cumulative_wheel_revolutions = 0;
1100         }
1101     } else {
1102         if (instance->cumulative_wheel_revolutions < (0xffffffff - wheel_revolution)){
1103             instance->cumulative_wheel_revolutions += wheel_revolution;
1104         } else {
1105             instance->cumulative_wheel_revolutions = 0xffffffff;
1106         }
1107     }
1108 }
1109 
1110 void cycling_power_service_server_add_crank_revolution(uint16_t crank_revolution, uint16_t crank_event_time_s){
1111     cycling_power_t * instance = &cycling_power;
1112     instance->last_crank_event_time_s = crank_event_time_s;
1113     instance->cumulative_crank_revolutions += crank_revolution;
1114 }
1115 
1116 void cycling_power_service_add_energy(uint16_t energy_kJ){
1117     cycling_power_t * instance = &cycling_power;
1118     if (instance->accumulated_energy_kJ <= (0xffffu - energy_kJ)){
1119         instance->accumulated_energy_kJ += energy_kJ;
1120     } else {
1121         instance->accumulated_energy_kJ = 0xffff;
1122     }
1123 }
1124 
1125 void cycling_power_service_server_set_instantaneous_power(int16_t instantaneous_power_W){
1126     cycling_power_t * instance = &cycling_power;
1127     instance->instantaneous_power_W = instantaneous_power_W;
1128 }
1129 
1130 void cycling_power_service_server_set_pedal_power_balance(uint8_t pedal_power_balance_percentage){
1131     cycling_power_t * instance = &cycling_power;
1132     instance->pedal_power_balance_percentage = pedal_power_balance_percentage;
1133 }
1134 
1135 void cycling_power_service_server_set_force_magnitude_values(int force_magnitude_count, int16_t * force_magnitude_N_array){
1136     cycling_power_t * instance = &cycling_power;
1137     instance->force_magnitude_count = force_magnitude_count;
1138     instance->vector_instantaneous_force_magnitude_N_array = force_magnitude_N_array;
1139 }
1140 
1141 void cycling_power_service_server_set_torque_magnitude_values(int torque_magnitude_count, int16_t * torque_magnitude_Nm_array){
1142     cycling_power_t * instance = &cycling_power;
1143     instance->torque_magnitude_count = torque_magnitude_count;
1144     instance->vector_instantaneous_torque_magnitude_Nm_array = torque_magnitude_Nm_array;
1145 }
1146 
1147 void cycling_power_service_server_set_first_crank_measurement_angle(uint16_t first_crank_measurement_angle_degree){
1148     cycling_power_t * instance = &cycling_power;
1149     instance->vector_first_crank_measurement_angle_degree = first_crank_measurement_angle_degree;
1150 }
1151 
1152 void cycling_power_service_server_set_instantaneous_measurement_direction(cycling_power_instantaneous_measurement_direction_t direction){
1153     cycling_power_t * instance = &cycling_power;
1154     instance->vector_instantaneous_measurement_direction = direction;
1155 }
1156 
1157 void cycling_power_service_server_set_force_magnitude(int16_t min_force_magnitude_N, int16_t max_force_magnitude_N){
1158     cycling_power_t * instance = &cycling_power;
1159     instance->minimum_force_magnitude_N = min_force_magnitude_N;
1160     instance->maximum_force_magnitude_N = max_force_magnitude_N;
1161 }
1162 
1163 void cycling_power_service_server_set_torque_magnitude(int16_t min_torque_magnitude_Nm, int16_t max_torque_magnitude_Nm){
1164     cycling_power_t * instance = &cycling_power;
1165     instance->minimum_torque_magnitude_Nm = min_torque_magnitude_Nm;
1166     instance->maximum_torque_magnitude_Nm = max_torque_magnitude_Nm;
1167 }
1168 
1169 void cycling_power_service_server_set_angle(uint16_t min_angle_degree, uint16_t max_angle_degree){
1170     cycling_power_t * instance = &cycling_power;
1171     instance->minimum_angle_degree = min_angle_degree;
1172     instance->maximum_angle_degree = max_angle_degree;
1173 }
1174 
1175 void cycling_power_service_server_set_top_dead_spot_angle(uint16_t top_dead_spot_angle_degree){
1176     cycling_power_t * instance = &cycling_power;
1177     instance->top_dead_spot_angle_degree = top_dead_spot_angle_degree;
1178 }
1179 
1180 void cycling_power_service_server_set_bottom_dead_spot_angle(uint16_t bottom_dead_spot_angle_degree){
1181     cycling_power_t * instance = &cycling_power;
1182     instance->bottom_dead_spot_angle_degree = bottom_dead_spot_angle_degree;
1183 }
1184 
1185 static int gatt_date_is_valid(gatt_date_time_t date){
1186     if ((date.year != 0u) && ((date.year < 1582u) || (date.year > 9999u))) return 0u;
1187     if ((date.month != 0u) && (date.month > 12u)) return 0u;
1188     if ((date.day != 0u) && (date.day > 31u)) return 0u;
1189 
1190     if (date.hours > 23u) return 0u;
1191     if (date.minutes > 59u) return 0u;
1192     if (date.seconds > 59u) return 0u;
1193     return 1;
1194 }
1195 
1196 int cycling_power_service_server_set_factory_calibration_date(gatt_date_time_t date){
1197     if (!gatt_date_is_valid(date)) return 0;
1198 
1199     cycling_power_t * instance = &cycling_power;
1200     instance->factory_calibration_date = date;
1201     return 1;
1202 }
1203 
1204 void cycling_power_service_server_set_sampling_rate(uint8_t sampling_rate_Hz){
1205     cycling_power_t * instance = &cycling_power;
1206     instance->sampling_rate_Hz = sampling_rate_Hz;
1207 }
1208 
1209 
1210 void cycling_power_service_server_update_values(void){
1211     cycling_power_t * instance = &cycling_power;
1212 
1213     if (instance->measurement_server_configuration_descriptor_broadcast){
1214         instance->measurement_broadcast_callback.callback = &cycling_power_service_broadcast_can_send_now;
1215         instance->measurement_broadcast_callback.context  = (void*) instance;
1216         att_server_register_can_send_now_callback(&instance->measurement_broadcast_callback, instance->con_handle);
1217     }
1218 
1219     if (instance->measurement_client_configuration_descriptor_notify){
1220         instance->measurement_notify_callback.callback = &cycling_power_service_measurement_can_send_now;
1221         instance->measurement_notify_callback.context  = (void*) instance;
1222         att_server_register_can_send_now_callback(&instance->measurement_notify_callback, instance->con_handle);
1223     }
1224 
1225     if (instance->vector_client_configuration_descriptor_notify){
1226         instance->vector_notify_callback.callback = &cycling_power_service_vector_can_send_now;
1227         instance->vector_notify_callback.context  = (void*) instance;
1228         att_server_register_can_send_now_callback(&instance->vector_notify_callback, instance->con_handle);
1229     }
1230 }
1231 
1232 void cycling_power_service_server_packet_handler(btstack_packet_handler_t callback){
1233     if (callback == NULL){
1234         log_error("cycling_power_service_server_packet_handler called with NULL callback");
1235         return;
1236     }
1237     cycling_power_t * instance = &cycling_power;
1238     instance->calibration_callback = callback;
1239 }
1240 
1241 void cycling_power_server_calibration_done(cycling_power_sensor_measurement_context_t measurement_type, uint16_t calibrated_value){
1242     cycling_power_t * instance = &cycling_power;
1243     if (instance->response_value != CP_RESPONSE_VALUE_W4_VALUE_AVAILABLE){
1244         return;
1245     }
1246     instance->response_value = CP_RESPONSE_VALUE_SUCCESS;
1247 
1248     switch (measurement_type){
1249         case CP_SENSOR_MEASUREMENT_CONTEXT_FORCE:
1250             instance->current_force_magnitude_N = calibrated_value;
1251             break;
1252         case CP_SENSOR_MEASUREMENT_CONTEXT_TORQUE:
1253             instance->current_torque_magnitude_Nm = calibrated_value;
1254             break;
1255         default:
1256             instance->response_value = CP_RESPONSE_VALUE_INVALID_PARAMETER;
1257             break;
1258     }
1259 
1260     if (instance->response_value == CP_RESPONSE_VALUE_SUCCESS){
1261         switch (calibrated_value){
1262             case CP_CALIBRATION_STATUS_INCORRECT_CALIBRATION_POSITION:
1263             case CP_CALIBRATION_STATUS_MANUFACTURER_SPECIFIC_ERROR_FOLLOWS:
1264                 instance->response_value = CP_RESPONSE_VALUE_OPERATION_FAILED;
1265                 instance->response_value = CP_RESPONSE_VALUE_OPERATION_FAILED;
1266                 break;
1267             default:
1268                 break;
1269         }
1270     }
1271 
1272     if (instance->control_point_client_configuration_descriptor_indicate){
1273         instance->control_point_indicate_callback.callback = &cycling_power_service_response_can_send_now;
1274         instance->control_point_indicate_callback.context  = (void*) instance;
1275         att_server_register_can_send_now_callback(&instance->control_point_indicate_callback, instance->con_handle);
1276     }
1277 }
1278 
1279 void cycling_power_server_enhanced_calibration_done(cycling_power_sensor_measurement_context_t measurement_type,
1280                 uint16_t calibrated_value, uint16_t manufacturer_company_id,
1281                 uint8_t num_manufacturer_specific_data, uint8_t * manufacturer_specific_data){
1282     cycling_power_t * instance = &cycling_power;
1283     if (instance->response_value != CP_RESPONSE_VALUE_W4_VALUE_AVAILABLE) return;
1284     instance->response_value = CP_RESPONSE_VALUE_SUCCESS;
1285 
1286     switch (measurement_type){
1287         case CP_SENSOR_MEASUREMENT_CONTEXT_FORCE:
1288             instance->current_force_magnitude_N = calibrated_value;
1289             break;
1290         case CP_SENSOR_MEASUREMENT_CONTEXT_TORQUE:
1291             instance->current_torque_magnitude_Nm = calibrated_value;
1292             break;
1293         default:
1294             instance->response_value = CP_RESPONSE_VALUE_INVALID_PARAMETER;
1295             break;
1296     }
1297 
1298     if (instance->response_value == CP_RESPONSE_VALUE_SUCCESS){
1299         switch (calibrated_value){
1300             case CP_CALIBRATION_STATUS_INCORRECT_CALIBRATION_POSITION:
1301             case CP_CALIBRATION_STATUS_MANUFACTURER_SPECIFIC_ERROR_FOLLOWS:
1302                 instance->response_value = CP_RESPONSE_VALUE_OPERATION_FAILED;
1303                 instance->response_value = CP_RESPONSE_VALUE_OPERATION_FAILED;
1304                 break;
1305             default:
1306                 break;
1307         }
1308         instance->manufacturer_company_id = manufacturer_company_id;
1309         instance->num_manufacturer_specific_data = num_manufacturer_specific_data;
1310         instance->manufacturer_specific_data = manufacturer_specific_data;
1311     }
1312 
1313     if (instance->control_point_client_configuration_descriptor_indicate){
1314         instance->control_point_indicate_callback.callback = &cycling_power_service_response_can_send_now;
1315         instance->control_point_indicate_callback.context  = (void*) instance;
1316         att_server_register_can_send_now_callback(&instance->control_point_indicate_callback, instance->con_handle);
1317     }
1318 }
1319