xref: /btstack/src/ble/gatt-service/battery_service_client.h (revision 503a627edab6ba8492c3d0cdd9ac598fe2b0f08a)
1 /*
2  * Copyright (C) 2021 BlueKitchen GmbH
3  *
4  * Redistribution and use in source and binary forms, with or without
5  * modification, are permitted provided that the following conditions
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7  *
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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.
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15  *    from this software without specific prior written permission.
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20  * THIS SOFTWARE IS PROVIDED BY BLUEKITCHEN GMBH AND CONTRIBUTORS
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37 
38 #ifndef BATTERY_SERVICE_CLIENT_H
39 #define BATTERY_SERVICE_CLIENT_H
40 
41 #include <stdint.h>
42 #include "btstack_defines.h"
43 #include "bluetooth.h"
44 #include "btstack_linked_list.h"
45 #include "ble/gatt_client.h"
46 
47 #if defined __cplusplus
48 extern "C" {
49 #endif
50 
51 /**
52  * @text The Battery Service Client connects to the Battery Services of a remote device
53  * and queries its battery level values. Level updates are either received via notifications
54  * (if supported by the remote Battery Service), or by manual polling.
55  */
56 
57 #ifndef MAX_NUM_BATTERY_SERVICES
58 #define MAX_NUM_BATTERY_SERVICES 3
59 #endif
60 
61 #if MAX_NUM_BATTERY_SERVICES > 8
62     #error "Maximum number of Battery Services exceeded"
63 #endif
64 
65 
66 typedef enum {
67     BATTERY_SERVICE_CLIENT_STATE_IDLE,
68     BATTERY_SERVICE_CLIENT_STATE_W2_QUERY_SERVICE,
69     BATTERY_SERVICE_CLIENT_STATE_W4_SERVICE_RESULT,
70     BATTERY_SERVICE_CLIENT_STATE_W2_QUERY_CHARACTERISTICS,
71     BATTERY_SERVICE_CLIENT_STATE_W4_CHARACTERISTIC_RESULT,
72 
73 #ifdef ENABLE_TESTING_SUPPORT
74     BATTERY_SERVICE_CLIENT_STATE_W2_QUERY_CHARACTERISTIC_DESCRIPTORS,
75     BATTERY_SERVICE_CLIENT_STATE_W4_CHARACTERISTIC_DESCRIPTORS_RESULT,
76 #endif
77 
78     BATTERY_SERVICE_CLIENT_STATE_W2_REGISTER_NOTIFICATION,
79     BATTERY_SERVICE_CLIENT_STATE_W4_NOTIFICATION_REGISTERED,
80     BATTERY_SERVICE_CLIENT_STATE_CONNECTED,
81 
82 #ifdef ENABLE_TESTING_SUPPORT
83     BATTERY_SERVICE_CLIENT_W2_READ_CHARACTERISTIC_CONFIGURATION,
84     BATTERY_SERVICE_CLIENT_W4_CHARACTERISTIC_CONFIGURATION_RESULT,
85 #endif
86 } battery_service_client_state_t;
87 
88 
89 typedef struct {
90     // service
91     uint16_t start_handle;
92     uint16_t end_handle;
93 
94     // characteristic
95     uint16_t properties;
96     uint16_t value_handle;
97 
98 #ifdef ENABLE_TESTING_SUPPORT
99     uint16_t ccc_handle;
100 #endif
101 
102     gatt_client_notification_t notification_listener;
103 } battery_service_t;
104 
105 
106 typedef struct {
107     btstack_linked_item_t item;
108 
109     hci_con_handle_t  con_handle;
110     uint16_t          cid;
111     battery_service_client_state_t  state;
112     btstack_packet_handler_t client_handler;
113 
114     uint32_t poll_interval_ms;
115 
116     uint8_t num_instances;
117     battery_service_t services[MAX_NUM_BATTERY_SERVICES];
118 
119     // used for discovering characteristics and polling
120     uint8_t service_index;
121     uint8_t poll_bitmap;
122     uint8_t need_poll_bitmap;
123     uint8_t polled_service_index;
124     btstack_timer_source_t poll_timer;
125 } battery_service_client_t;
126 
127 /* API_START */
128 
129 
130 /**
131  * @brief Initialize Battery Service.
132  */
133 void battery_service_client_init(void);
134 
135 /**
136  * @brief Connect to Battery Services of remote device. The client will try to register for notifications.
137  * If notifications are not supported by remote Battery Service, the client will poll battery level
138  * If poll_interval_ms is 0, polling is disabled, and only notifications will be received.
139  * In either case, the battery level is received via GATTSERVICE_SUBEVENT_BATTERY_SERVICE_LEVEL event.
140  * The battery level is reported as percentage, i.e. 100 = full and it is valid if the ATTT status is equal to ATT_ERROR_SUCCESS,
141  * see ATT errors (see bluetooth.h) for other values.
142  *
143  * For manual polling, see battery_service_client_read_battery_level below.
144  *
145  * Event GATTSERVICE_SUBEVENT_BATTERY_SERVICE_CONNECTED is emitted with status ERROR_CODE_SUCCESS on success, otherwise
146  * GATT_CLIENT_IN_WRONG_STATE, ERROR_CODE_UNSUPPORTED_FEATURE_OR_PARAMETER_VALUE if no battery service is found, or ATT errors (see bluetooth.h).
147  * This event event also returns number of battery instances found on remote server, as well as poll bitmap that indicates which indexes
148  * of services require polling, i.e. they do not support notification on battery level change,
149  *
150  * @param con_handle
151  * @param packet_handler
152  * @param poll_interval_ms or 0 to disable polling
153  * @param battery_service_cid
154  * @return status ERROR_CODE_SUCCESS on success, otherwise ERROR_CODE_COMMAND_DISALLOWED if there is already a client associated with con_handle, or BTSTACK_MEMORY_ALLOC_FAILED
155  */
156 uint8_t battery_service_client_connect(hci_con_handle_t con_handle, btstack_packet_handler_t packet_handler, uint32_t poll_interval_ms, uint16_t * battery_service_cid);
157 
158 /**
159  * @brief Read battery level for service with given index. Event GATTSERVICE_SUBEVENT_BATTERY_SERVICE_LEVEL is
160  * received with battery level (unit is in percentage, i.e. 100 = full). The battery level is valid if the ATTT status
161  * is equal to ATT_ERROR_SUCCESS, see ATT errors (see bluetooth.h) for other values.
162  * @param battery_service_cid
163  * @param service_index
164  * @return status
165  */
166 uint8_t battery_service_client_read_battery_level(uint16_t battery_service_cid, uint8_t service_index);
167 
168 /**
169  * @brief Disconnect from Battery Service.
170  * @param battery_service_cid
171  * @return status
172  */
173 uint8_t battery_service_client_disconnect(uint16_t battery_service_cid);
174 
175 /**
176  * @brief De-initialize Battery Service.
177  */
178 void battery_service_client_deinit(void);
179 
180 /* API_END */
181 
182 #if defined __cplusplus
183 }
184 #endif
185 
186 #endif
187