gatttool --help-all 命令的说明如下:
Usage:
gatttool [OPTION...]
Help Options:
-h, --help Show help options
--help-all Show all help options
--help-gatt Show all GATT commands
--help-params Show all Primary Services/Characteristics arguments
--help-char-read-write Show all Characteristics Value/Descriptor Read/Write arguments
GATT commands
--primary Primary Service Discovery
--characteristics Characteristics Discovery
--char-read Characteristics Value/Descriptor Read
--char-write Characteristics Value Write Without Response (Write Command)
--char-write-req Characteristics Value Write (Write Request)
--char-desc Characteristics Descriptor Discovery
--listen Listen for notifications and indications
Primary Services/Characteristics arguments
-s, --start=0x0001 Starting handle(optional)
-e, --end=0xffff Ending handle(optional)
-u, --uuid=0x1801 UUID16 or UUID128(optional)
Characteristics Value/Descriptor Read/Write arguments
-a, --handle=0x0001 Read/Write characteristic by handle(required)
-n, --value=0x0001 Write characteristic value (required for write operation)
Application Options:
-i, --adapter=hciX Specify local adapter interface
-b, --device=MAC Specify remote Bluetooth address
-t, --addr-type=[public | random] Set LE address type. Default: public
-m, --mtu=MTU Specify the MTU size
-p, --psm=PSM Specify the PSM for GATT/ATT over BR/EDR
-l, --sec-level=[low | medium | high] Set security level. Default: low
-I, --interactive Use interactive mode
--characteristics指的是“特征发现”，而--char-desc指的是“特征描述符”，它们有什么区别呢？
如果我对同一个BLE设备运行它们两个，我会得到相同UUID的不同句柄吗？例如：
gatttool --device=C4:7C:8D:62:D3:19 --characteristics
...
handle = 0x0032, char properties = 0x0a, char value handle = 0x0033, uuid = 00001a00-0000-1000-8000-00805f9b34fb
...
gatttool --device=C4:7C:8D:62:D3:19 --char-desc
...
handle = 0x0033, uuid = 00001a00-0000-1000-8000-00805f9b34fb
...
在使用read/write（-a参数）时，我应该使用来自--characteristics还是--char-desc的句柄？