xref: /btstack/src/ble/gatt-service/battery_service_client.h (revision b28dc8004dd8d4fb9020a6dcd2bc81f05d36a008)
1 /*
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37 
38 /**
39  * @title Battery Service Client
40  *
41  */
42 
43 #ifndef BATTERY_SERVICE_CLIENT_H
44 #define BATTERY_SERVICE_CLIENT_H
45 
46 #include <stdint.h>
47 #include "btstack_defines.h"
48 #include "bluetooth.h"
49 #include "btstack_linked_list.h"
50 #include "ble/gatt_client.h"
51 
52 #if defined __cplusplus
53 extern "C" {
54 #endif
55 
56 /**
57  * @text The Battery Service Client connects to the Battery Services of a remote device
58  * and queries its battery level values. Level updates are either received via notifications
59  * (if supported by the remote Battery Service), or by manual polling.
60  */
61 
62 #ifndef MAX_NUM_BATTERY_SERVICES
63 #define MAX_NUM_BATTERY_SERVICES 3
64 #endif
65 
66 #if MAX_NUM_BATTERY_SERVICES > 8
67     #error "Maximum number of Battery Services exceeded"
68 #endif
69 
70 
71 typedef enum {
72     BATTERY_SERVICE_CLIENT_STATE_IDLE,
73     BATTERY_SERVICE_CLIENT_STATE_W2_QUERY_SERVICE,
74     BATTERY_SERVICE_CLIENT_STATE_W4_SERVICE_RESULT,
75     BATTERY_SERVICE_CLIENT_STATE_W2_QUERY_CHARACTERISTICS,
76     BATTERY_SERVICE_CLIENT_STATE_W4_CHARACTERISTIC_RESULT,
77 
78 #ifdef ENABLE_TESTING_SUPPORT
79     BATTERY_SERVICE_CLIENT_STATE_W2_QUERY_CHARACTERISTIC_DESCRIPTORS,
80     BATTERY_SERVICE_CLIENT_STATE_W4_CHARACTERISTIC_DESCRIPTORS_RESULT,
81 #endif
82 
83     BATTERY_SERVICE_CLIENT_STATE_W2_REGISTER_NOTIFICATION,
84     BATTERY_SERVICE_CLIENT_STATE_W4_NOTIFICATION_REGISTERED,
85     BATTERY_SERVICE_CLIENT_STATE_CONNECTED,
86 
87 #ifdef ENABLE_TESTING_SUPPORT
88     BATTERY_SERVICE_CLIENT_W2_READ_CHARACTERISTIC_CONFIGURATION,
89     BATTERY_SERVICE_CLIENT_W4_CHARACTERISTIC_CONFIGURATION_RESULT,
90 #endif
91 } battery_service_client_state_t;
92 
93 
94 typedef struct {
95     // service
96     uint16_t start_handle;
97     uint16_t end_handle;
98 
99     // characteristic
100     uint16_t properties;
101     uint16_t value_handle;
102 
103 #ifdef ENABLE_TESTING_SUPPORT
104     uint16_t ccc_handle;
105 #endif
106 
107     gatt_client_notification_t notification_listener;
108 } battery_service_t;
109 
110 
111 typedef struct {
112     btstack_linked_item_t item;
113 
114     hci_con_handle_t  con_handle;
115     uint16_t          cid;
116     battery_service_client_state_t  state;
117     btstack_packet_handler_t client_handler;
118 
119     uint32_t poll_interval_ms;
120 
121     uint8_t num_instances;
122     battery_service_t services[MAX_NUM_BATTERY_SERVICES];
123 
124     // used for discovering characteristics and polling
125     uint8_t service_index;
126     uint8_t poll_bitmap;
127     uint8_t need_poll_bitmap;
128     uint8_t polled_service_index;
129     btstack_timer_source_t poll_timer;
130 } battery_service_client_t;
131 
132 /* API_START */
133 
134 
135 /**
136  * @brief Initialize Battery Service.
137  */
138 void battery_service_client_init(void);
139 
140 /**
141  * @brief Connect to Battery Services of remote device. The client will try to register for notifications.
142  * If notifications are not supported by remote Battery Service, the client will poll battery level
143  * If poll_interval_ms is 0, polling is disabled, and only notifications will be received.
144  * In either case, the battery level is received via GATTSERVICE_SUBEVENT_BATTERY_SERVICE_LEVEL event.
145  * 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,
146  * see ATT errors (see bluetooth.h) for other values.
147  *
148  * For manual polling, see battery_service_client_read_battery_level below.
149  *
150  * Event GATTSERVICE_SUBEVENT_BATTERY_SERVICE_CONNECTED is emitted with status ERROR_CODE_SUCCESS on success, otherwise
151  * GATT_CLIENT_IN_WRONG_STATE, ERROR_CODE_UNSUPPORTED_FEATURE_OR_PARAMETER_VALUE if no battery service is found, or ATT errors (see bluetooth.h).
152  * This event event also returns number of battery instances found on remote server, as well as poll bitmap that indicates which indexes
153  * of services require polling, i.e. they do not support notification on battery level change,
154  *
155  * @param con_handle
156  * @param packet_handler
157  * @param poll_interval_ms or 0 to disable polling
158  * @param battery_service_cid
159  * @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
160  */
161 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);
162 
163 /**
164  * @brief Read battery level for service with given index. Event GATTSERVICE_SUBEVENT_BATTERY_SERVICE_LEVEL is
165  * received with battery level (unit is in percentage, i.e. 100 = full). The battery level is valid if the ATTT status
166  * is equal to ATT_ERROR_SUCCESS, see ATT errors (see bluetooth.h) for other values.
167  * @param battery_service_cid
168  * @param service_index
169  * @return status
170  */
171 uint8_t battery_service_client_read_battery_level(uint16_t battery_service_cid, uint8_t service_index);
172 
173 /**
174  * @brief Disconnect from Battery Service.
175  * @param battery_service_cid
176  * @return status
177  */
178 uint8_t battery_service_client_disconnect(uint16_t battery_service_cid);
179 
180 /**
181  * @brief De-initialize Battery Service.
182  */
183 void battery_service_client_deinit(void);
184 
185 /* API_END */
186 
187 #if defined __cplusplus
188 }
189 #endif
190 
191 #endif
192