Overview
本文基于DA1458x SDK 5.0.4。
Device Information Service 以下简称DIS or DISS。DISS的代码主要有以下两个组C文件组成
另，DISS是依赖于APP_TASK任务来调度管理的。具体框架如下图（摘自Dialog官方文档）
Full DISS Database Description （DISS Database 分析）
DISS的Database的变量名为 diss_att_db
由以下19个成员组成
| No. | Name | Description |
|---|---|---|
| 1 | DIS_IDX_SVC | Device Information Service Declaration |
| 2 | DIS_IDX_MANUFACTURER_NAME_CHAR | Manufacturer Name Characteristic Declaration |
| 3 | DIS_IDX_MANUFACTURER_NAME_VAL | Manufacturer Name Characteristic Value |
| 4 | DIS_IDX_MODEL_NB_STR_CHAR | Model Number String Characteristic Declaration |
| 5 | DIS_IDX_MODEL_NB_STR_VAL | Model Number String Characteristic Value |
| 6 | DIS_IDX_SERIAL_NB_STR_CHAR | Serial Number String Characteristic Declaration |
| 7 | DIS_IDX_SERIAL_NB_STR_VAL | Serial Number String Characteristic Value |
| 8 | DIS_IDX_HARD_REV_STR_CHAR | Hardware Revision String Characteristic Declaration |
| 9 | DIS_IDX_HARD_REV_STR_VAL | Hardware Revision String Characteristic Value |
| 10 | DIS_IDX_FIRM_REV_STR_CHAR | Firmware Revision String Characteristic Declaration |
| 11 | DIS_IDX_FIRM_REV_STR_VAL | Firmware Revision String Characteristic Value |
| 12 | DIS_IDX_SW_REV_STR_CHAR | Software Revision String Characteristic Declaration |
| 13 | DIS_IDX_SW_REV_STR_VAL | Software Revision String Characteristic Value |
| 14 | DIS_IDX_SYSTEM_ID_CHAR | System ID Characteristic Declaration |
| 15 | DIS_IDX_SYSTEM_ID_VAL | System ID Characteristic Value |
| 16 | DIS_IDX_IEEE_CHAR | IEEE 11073-20601 Regulatory Certification Data List Characteristic Declaration |
| 17 | DIS_IDX_IEEE_VAL | IEEE 11073-20601 Regulatory Certification Data List Characteristic Value |
| 18 | DIS_IDX_PNP_ID_CHAR | PnP ID Characteristic Declaration |
| 19 | DIS_IDX_PNP_ID_VAL | PnP ID Characteristic Value |
这个变量非常重要，本文我们就围绕着它来一步步来分析。
diss_att_db结构体数组索引
首先这是一个结构体数组的索引，该索引采取的是枚举类型，方便阅读和理解。
///Attributes State Machine
enum
{
DIS_IDX_SVC,
DIS_IDX_MANUFACTURER_NAME_CHAR,
DIS_IDX_MANUFACTURER_NAME_VAL,
DIS_IDX_MODEL_NB_STR_CHAR,
DIS_IDX_MODEL_NB_STR_VAL,
DIS_IDX_SERIAL_NB_STR_CHAR,
DIS_IDX_SERIAL_NB_STR_VAL,
DIS_IDX_HARD_REV_STR_CHAR,
DIS_IDX_HARD_REV_STR_VAL,
DIS_IDX_FIRM_REV_STR_CHAR,
DIS_IDX_FIRM_REV_STR_VAL,
DIS_IDX_SW_REV_STR_CHAR,
DIS_IDX_SW_REV_STR_VAL,
DIS_IDX_SYSTEM_ID_CHAR,
DIS_IDX_SYSTEM_ID_VAL,
DIS_IDX_IEEE_CHAR,
DIS_IDX_IEEE_VAL,
DIS_IDX_PNP_ID_CHAR,
DIS_IDX_PNP_ID_VAL,
DIS_IDX_NB,
};接下来我们看下attm_desc这个结构体的定义
struct attm_desc 结构体的定义
这个结构体的定义如下
/// Attribute description (used to create database)
struct attm_desc
{
/// Element UUID
uint16_t uuid;
/// Attribute permission
uint16_t perm;
/// Maximum length of the element
att_size_t max_length;
/// Current length of the element
att_size_t length;
/// Element value array
uint8_t* value;
};我们可以看到，第一个成员是16位UUID，用来记录这个Attribute（属性）的UUID；
第二个成员是Attribute permission（属性权限）；
第三个成员是Maximum length of the element（元素的最大长度）；
第四个成员是Current length of the element（当前元素的长处）；
第五个成员是Element Value array（元素数组）。
uuid和perm为16bit无符号整型变量，value为uint8_t数组指针，att_size_t类型其实uint16_t
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/// Attribute length type
typedef uint16_t att_size_t;diss_att_db定义
定义如下（diss.c文件中）
/*
* DIS ATTRIBUTES
****************************************************************************************
*/
/// Full DIS Database Description - Used to add attributes into the database
const struct attm_desc diss_att_db[DIS_IDX_NB] =
{
// Device Information Service Declaration
[DIS_IDX_SVC] = {ATT_DECL_PRIMARY_SERVICE, PERM(RD, ENABLE), sizeof(diss_dis_svc),
sizeof(diss_dis_svc), (uint8_t *)&diss_dis_svc},
// Manufacturer Name Characteristic Declaration
[DIS_IDX_MANUFACTURER_NAME_CHAR] = {ATT_DECL_CHARACTERISTIC, PERM(RD, ENABLE), sizeof(diss_manufacturer_name_char),
sizeof(diss_manufacturer_name_char), (uint8_t *)&diss_manufacturer_name_char},
// Manufacturer Name Characteristic Value
[DIS_IDX_MANUFACTURER_NAME_VAL] = {ATT_CHAR_MANUF_NAME, PERM(RD, ENABLE), DIS_VAL_MAX_LEN, 0, NULL},
// Model Number String Characteristic Declaration
[DIS_IDX_MODEL_NB_STR_CHAR] = {ATT_DECL_CHARACTERISTIC, PERM(RD, ENABLE), sizeof(diss_model_nb_str_char),
sizeof(diss_model_nb_str_char), (uint8_t *)&diss_model_nb_str_char},
// Model Number String Characteristic Value
[DIS_IDX_MODEL_NB_STR_VAL] = {ATT_CHAR_MODEL_NB, PERM(RD, ENABLE), DIS_VAL_MAX_LEN, 0, NULL},
// Serial Number String Characteristic Declaration
[DIS_IDX_SERIAL_NB_STR_CHAR] = {ATT_DECL_CHARACTERISTIC, PERM(RD, ENABLE), sizeof(diss_serial_nb_str_char),
sizeof(diss_serial_nb_str_char), (uint8_t *)&diss_serial_nb_str_char},
// Serial Number String Characteristic Value
[DIS_IDX_SERIAL_NB_STR_VAL] = {ATT_CHAR_SERIAL_NB, PERM(RD, ENABLE), DIS_VAL_MAX_LEN, 0, NULL},
// Hardware Revision String Characteristic Declaration
[DIS_IDX_HARD_REV_STR_CHAR] = {ATT_DECL_CHARACTERISTIC, PERM(RD, ENABLE), sizeof(diss_hard_rev_str_char),
sizeof(diss_hard_rev_str_char), (uint8_t *)&diss_hard_rev_str_char},
// Hardware Revision String Characteristic Value
[DIS_IDX_HARD_REV_STR_VAL] = {ATT_CHAR_HW_REV, PERM(RD, ENABLE), DIS_VAL_MAX_LEN, 0, NULL},
// Firmware Revision String Characteristic Declaration
[DIS_IDX_FIRM_REV_STR_CHAR] = {ATT_DECL_CHARACTERISTIC, PERM(RD, ENABLE), sizeof(diss_firm_rev_str_char),
sizeof(diss_firm_rev_str_char), (uint8_t *)&diss_firm_rev_str_char},
// Firmware Revision String Characteristic Value
[DIS_IDX_FIRM_REV_STR_VAL] = {ATT_CHAR_FW_REV, PERM(RD, ENABLE), DIS_VAL_MAX_LEN, 0, NULL},
// Software Revision String Characteristic Declaration
[DIS_IDX_SW_REV_STR_CHAR] = {ATT_DECL_CHARACTERISTIC, PERM(RD, ENABLE), sizeof(diss_sw_rev_str_char),
sizeof(diss_sw_rev_str_char), (uint8_t *)&diss_sw_rev_str_char},
// Software Revision String Characteristic Value
[DIS_IDX_SW_REV_STR_VAL] = {ATT_CHAR_SW_REV, PERM(RD, ENABLE), DIS_VAL_MAX_LEN, 0, NULL},
// System ID Characteristic Declaration
[DIS_IDX_SYSTEM_ID_CHAR] = {ATT_DECL_CHARACTERISTIC, PERM(RD, ENABLE), sizeof(diss_system_id_char),
sizeof(diss_system_id_char), (uint8_t *)&diss_system_id_char},
// System ID Characteristic Value
[DIS_IDX_SYSTEM_ID_VAL] = {ATT_CHAR_SYS_ID, PERM(RD, ENABLE), DIS_SYS_ID_LEN, 0, NULL},
// IEEE 11073-20601 Regulatory Certification Data List Characteristic Declaration
[DIS_IDX_IEEE_CHAR] = {ATT_DECL_CHARACTERISTIC, PERM(RD, ENABLE), sizeof(diss_ieee_char),
sizeof(diss_ieee_char), (uint8_t *)&diss_ieee_char},
// IEEE 11073-20601 Regulatory Certification Data List Characteristic Value
[DIS_IDX_IEEE_VAL] = {ATT_CHAR_IEEE_CERTIF, PERM(RD, ENABLE), DIS_VAL_MAX_LEN, 0, NULL},
// PnP ID Characteristic Declaration
[DIS_IDX_PNP_ID_CHAR] = {ATT_DECL_CHARACTERISTIC, PERM(RD, ENABLE), sizeof(diss_pnp_id_char),
sizeof(diss_pnp_id_char), (uint8_t *)&diss_pnp_id_char},
// PnP ID Characteristic Value
[DIS_IDX_PNP_ID_VAL] = {ATT_CHAR_PNP_ID, PERM(RD, ENABLE), DIS_PNP_ID_LEN, 0, NULL},
};由上述定义我们来一个个分析bas_att_db的五个成员变量。
[DIS_IDX_SVC]
首先是[DIS_IDX_SVC]成员变量。
DIS_IDX_SVC的value是diss_dis_svc变量，具体如下：
const att_svc_desc_t diss_dis_svc = ATT_SVC_BATTERY_SERVICE;我们可以看到diss_dis_svc被赋值为一个枚举类型变量，具体值为0x180A。
类似的还有ATT_SVC_GENERIC_ACCESS、ATT_SVC_GENERIC_ATTRIBUTE、ATT_SVC_BATTERY_SERVICE、ATT_SVC_HID等。
具体定义如下：
/// Common 16-bit Universal Unique Identifier
enum {
ATT_INVALID_UUID = 0,
/*----------------- SERVICES ---------------------*/
/// Generic Access Profile
ATT_SVC_GENERIC_ACCESS = 0x1800,
/// Attribute Profile
ATT_SVC_GENERIC_ATTRIBUTE,
...
/// Device Information Service
ATT_SVC_DEVICE_INFO = 0x180A,
...
/// Battery Service
ATT_SVC_BATTERY_SERVICE,
/// Blood Pressure Service
ATT_SVC_BLOOD_PRESSURE = 0x1810,
/// Alert Notification Service
ATT_SVC_ALERT_NTF = 0x1811,
/// HID Service
ATT_SVC_HID = 0x1812,
...
}
小结
DISS Database类型总结
| No. | Index | enum | 类型 | UUID |
|---|---|---|---|---|
| 1 | DIS_IDX_SVC | ATT_DECL_PRIMARY_SERVICE | DECLARATIONS | 0x2800 |
| 2 | DIS_IDX_MANUFACTURER_NAME_CHAR | ATT_DECL_CHARACTERISTIC | DECLARATIONS | 0x2803 |
| 3 | DIS_IDX_MANUFACTURER_NAME_VAL | ATT_CHAR_MANUF_NAME | CHARACTERISTICS | 0x2A29 |
| 4 | DIS_IDX_MODEL_NB_STR_CHAR | ATT_DECL_CHARACTERISTIC | DECLARATIONS | 0x2803 |
| 5 | DIS_IDX_MODEL_NB_STR_VAL | ATT_CHAR_MODEL_NB | CHARACTERISTICS | 0x2A24 |
| 6 | DIS_IDX_SERIAL_NB_STR_CHAR | ATT_DECL_CHARACTERISTIC | DECLARATIONS | 0x2803 |
| 7 | DIS_IDX_SERIAL_NB_STR_VAL | ATT_CHAR_SERIAL_NB | CHARACTERISTICS | 0x2A25 |
| 8 | DIS_IDX_HARD_REV_STR_CHAR | ATT_DECL_CHARACTERISTIC | DECLARATIONS | 0x2803 |
| 9 | DIS_IDX_HARD_REV_STR_VAL | ATT_CHAR_HW_REV | CHARACTERISTICS | 0x2A27 |
| 10 | DIS_IDX_FIRM_REV_STR_CHAR | ATT_DECL_CHARACTERISTIC | DECLARATIONS | 0x2803 |
| 11 | DIS_IDX_FIRM_REV_STR_VAL | ATT_CHAR_FW_REV | CHARACTERISTICS | 0x2A26 |
| 12 | DIS_IDX_SW_REV_STR_CHAR | ATT_DECL_CHARACTERISTIC | DECLARATIONS | 0x2803 |
| 13 | DIS_IDX_SW_REV_STR_VAL | ATT_CHAR_SW_REV | CHARACTERISTICS | 0x2A28 |
| 14 | DIS_IDX_SYSTEM_ID_CHAR | ATT_DECL_CHARACTERISTIC | DECLARATIONS | 0x2803 |
| 15 | DIS_IDX_SYSTEM_ID_VAL | ATT_CHAR_SYS_ID | CHARACTERISTICS | 0x2A23 |
| 16 | DIS_IDX_IEEE_CHAR | ATT_DECL_CHARACTERISTIC | DECLARATIONS | 0x2803 |
| 17 | DIS_IDX_IEEE_VAL | ATT_CHAR_IEEE_CERTIF | CHARACTERISTICS | 0x2A2A |
| 18 | DIS_IDX_PNP_ID_CHAR | ATT_DECL_CHARACTERISTIC | DECLARATIONS | 0x2803 |
| 19 | DIS_IDX_PNP_ID_VAL | ATT_CHAR_PNP_ID | CHARACTERISTICS | 0x2A50 |