gatttool的使用

1、使能hci接口

# hciconfig hci0 up

2、使用hcitool搜索BLE设备

# hcitool lescan

LE Scan ...

D0:39:72:BE:D2:26 (unknown)

D0:39:72:BE:D2:26 HMDongle

D0:39:72:BE:D2:26 (unknown)

搜索到设备后按CTRL+C停止搜索，设备名称为HMDongle，是一个蓝牙串口设备，MAC地址为D0:39:72:BE:D2:26

3、使用gatttool连接设备

先查看gatttool的help

# gattool -h

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

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

使用interactive方式连接设备

# gatttool -b D0:39:72:BE:D2:26 -I

[ ][D0:39:72:BE:D2:26][LE]>

查看help

[ ][D0:39:72:BE:D2:26][LE]> help

help Show this help

exit Exit interactive mode

quit Exit interactive mode

connect [address [address type]] Connect to a remote device

disconnect Disconnect from a remote device

primary [UUID] Primary Service Discovery

characteristics [start hnd [end hnd [UUID]]] Characteristics Discovery

char-desc [start hnd] [end hnd] Characteristics Descriptor Discovery

char-read-hnd <handle> [offset] Characteristics Value/Descriptor Read by handle

char-read-uuid <UUID> [start hnd] [end hnd] Characteristics Value/Descriptor Read by UUID

char-write-req <handle> <new value> Characteristic Value Write (Write Request)

char-write-cmd <handle> <new value> Characteristic Value Write (No response)

sec-level [low | medium | high] Set security level. Default: low

mtu <value> Exchange MTU for GATT/ATT

[ ][D0:39:72:BE:D2:26][LE]>

连接设备

[ ][D0:39:72:BE:D2:26][LE]> connect

[CON][D0:39:72:BE:D2:26][LE]>

连接成功之后命令行前面会有[CON]标识

查看设备提供的服务

[CON][D0:39:72:BE:D2:26][LE]> primary

[CON][D0:39:72:BE:D2:26][LE]>

attr handle: 0x0001, end grp handle: 0x000b uuid: 00001800-0000-1000-8000-00805f9b34fb

attr handle: 0x000c, end grp handle: 0x000f uuid: 00001801-0000-1000-8000-00805f9b34fb

attr handle: 0x0010, end grp handle: 0xffff uuid: 0000ffe0-0000-1000-8000-00805f9b34fb

查看特性

[CON][D0:39:72:BE:D2:26][LE]> characteristics

[CON][D0:39:72:BE:D2:26][LE]>

handle: 0x0002, char properties: 0x02, char value handle: 0x0003, uuid: 00002a00-0000-1000-8000-00805f9b34fb

handle: 0x0004, char properties: 0x02, char value handle: 0x0005, uuid: 00002a01-0000-1000-8000-00805f9b34fb

handle: 0x0006, char properties: 0x0a, char value handle: 0x0007, uuid: 00002a02-0000-1000-8000-00805f9b34fb

handle: 0x0008, char properties: 0x0a, char value handle: 0x0009, uuid: 00002a03-0000-1000-8000-00805f9b34fb

handle: 0x000a, char properties: 0x02, char value handle: 0x000b, uuid: 00002a04-0000-1000-8000-00805f9b34fb

handle: 0x000d, char properties: 0x20, char value handle: 0x000e, uuid: 00002a05-0000-1000-8000-00805f9b34fb

handle: 0x0011, char properties: 0x16, char value handle: 0x0012, uuid: 0000ffe1-0000-1000-8000-00805f9b34fb

其中handle是特性的句柄，char properties是特性的属性值，char value handle是特性值的句柄，uuid是特性的标识；

我想，可以把特性当作是设备特供的寄存器，寄存器会有属性，如只读、只写或可读可写，在蓝牙协议里面，还有notify的属性，当然，这个通知属性当作是寄存器的中断服务也是说得过去的；那么，第一个handle可以理解为寄存器的编号，第二个handle理解为寄存器的地址，properties即是寄存器属性，如果是可读可写，那么直接读写操作寄存器的地址即可。

上面列出了好多个特性，其中只有一个才是读写蓝牙串口的特性，很容易看得出来，它的uuid为ffe1，属性值为0x16，可读可写(without response)可通知。在这里，从蓝牙串口读取数据并不是直接去读取0x0012这个handle，而是通过notify获取数据，首先要使能notify功能，怎么使能呢，就是把特性值handle加1即0x0013，往这个0x0013handle写入0x0100，如：

[CON][D0:39:72:BE:D2:26][LE]> char-write-req 0x0013 0100

[CON][D0:39:72:BE:D2:26][LE]> Characteristic value was written successfully

往handle写入十六进制值时不要带0x，不然会出错

[CON][D0:39:72:BE:D2:26][LE]> char-write-req 0x0013 0x0100

[CON][D0:39:72:BE:D2:26][LE]> Characteristic Write Request failed: Attribute value length is invalid

如果要向设备发送串口数据就直接往0x0012写入数据即可

[CON][D0:39:72:BE:D2:26][LE]> char-write-cmd 0x0012 48

在这里我碰到了问题，始终获取不到蓝牙串口发送过来的数据，根本无法收到notify，即使加了--listen参数也不行，郁闷啊！首先设备是没问题的，使用lightblue工具都可以正常收发串口数据。