Android手機與BLE終端通信是如何進行的

這是我們為大家提供的一篇介紹Android手機與BLE終端通信是如何進行的的文章，接下來就讓我們一起來了解一下吧!

最近穿戴設備發展得很火，把相關技術也帶旺了，其中一項是BLE(Bluetooth Low Energy)。BLE是藍牙4.0的核心Profile，主打功能是快速搜索，快速連接，超低功耗保持連接和傳輸數據，弱點是數據傳輸速率低，由於BLE的低功耗特點，因此普遍用於穿戴設備。Android 4.3才開始支持BLE API，所以請各位客官把本文代碼運行在藍牙4.0和Android 4.3及其以上的系統，另外本文所用的BLE終端是一個藍牙4.0的串口藍牙模塊。

PS：我的i9100刷了4.4系統後，竟然也能跟BLE藍牙模塊通信。

BLE分為三部分Service、Characteristic、Descriptor，這三部分都由UUID作為唯一標示符。一個藍牙4.0的終端可以包含多個Service，一個Service可以包含多個Characteristic，一個Characteristic包含一個Value和多個Descriptor，一個Descriptor包含一個Value。一般來說，Characteristic是手機與BLE終端交換數據的關鍵，Characteristic有較多的跟權限相關的字段，例如PERMISSION和PROPERTY，而其中最常用的是PROPERTY，本文所用的BLE藍牙模塊竟然沒有標准的Characteristic的PERMISSION。Characteristic的PROPERTY可以通過位運算符組合來設置讀寫屬性，例如READ|WRITE、READ|WRITE_NO_RESPONSE|NOTIFY，因此讀取PROPERTY後要分解成所用的組合(本文代碼已含此分解方法)。

本文代碼改自Android 4.3 Sample的BluetoothLeGatt，把冗余代碼去掉，獲取的BLE設備信息都通過Log，還有一些必要的讀寫藍牙方法，應該算是簡化到大家一看就可以懂了。本文代碼可以到http://download.csdn.net/detail/hellogv/7228819下載。接下來貼出本文運行的結果，首先是連接BLE設備後，枚舉出設備所有Service、Characteristic、Descriptor，並且手機會往Characteristic uuid=0000ffe1-0000-1000-8000-00805f9b34fb寫入“send data->”字符串，BLE終端收到數據通過串口傳到PC串口助手(見PC串口助手的截圖)：

04-21 18:28:25.465: E/DeviceScanActivity(12254): -->service type:PRIMARY

04-21 18:28:25.465: E/DeviceScanActivity(12254): -->includedServices size:0

04-21 18:28:25.465: E/DeviceScanActivity(12254): -->service uuid:00001800-0000-1000-8000-00805f9b34fb

04-21 18:28:25.465: E/DeviceScanActivity(12254): ---->char uuid:00002a00-0000-1000-8000-00805f9b34fb

04-21 18:28:25.465: E/DeviceScanActivity(12254): ---->char permission:UNKNOW

04-21 18:28:25.465: E/DeviceScanActivity(12254): ---->char property:READ

04-21 18:28:25.465: E/DeviceScanActivity(12254): ---->char uuid:00002a01-0000-1000-8000-00805f9b34fb

04-21 18:28:25.470: E/DeviceScanActivity(12254): ---->char permission:UNKNOW

04-21 18:28:25.470: E/DeviceScanActivity(12254): ---->char property:READ

04-21 18:28:25.470: E/DeviceScanActivity(12254): ---->char uuid:00002a02-0000-1000-8000-00805f9b34fb

04-21 18:28:25.470: E/DeviceScanActivity(12254): ---->char permission:UNKNOW

04-21 18:28:25.470: E/DeviceScanActivity(12254): ---->char property:READ|WRITE|

04-21 18:28:25.470: E/DeviceScanActivity(12254): ---->char uuid:00002a03-0000-1000-8000-00805f9b34fb

04-21 18:28:25.470: E/DeviceScanActivity(12254): ---->char permission:UNKNOW

04-21 18:28:25.475: E/DeviceScanActivity(12254): ---->char property:READ|WRITE|

04-21 18:28:25.475: E/DeviceScanActivity(12254): ---->char uuid:00002a04-0000-1000-8000-00805f9b34fb

04-21 18:28:25.475: E/DeviceScanActivity(12254): ---->char permission:UNKNOW

04-21 18:28:25.475: E/DeviceScanActivity(12254): ---->char property:READ

04-21 18:28:25.475: E/DeviceScanActivity(12254): -->service type:PRIMARY

04-21 18:28:25.475: E/DeviceScanActivity(12254): -->includedServices size:0

04-21 18:28:25.475: E/DeviceScanActivity(12254): -->service uuid:00001801-0000-1000-8000-00805f9b34fb

04-21 18:28:25.480: E/DeviceScanActivity(12254): ---->char uuid:00002a05-0000-1000-8000-00805f9b34fb

04-21 18:28:25.480: E/DeviceScanActivity(12254): ---->char permission:UNKNOW

04-21 18:28:25.480: E/DeviceScanActivity(12254): ---->char property:INDICATE

04-21 18:28:25.480: E/DeviceScanActivity(12254): -------->desc uuid:00002902-0000-1000-8000-00805f9b34fb

04-21 18:28:25.480: E/DeviceScanActivity(12254): -------->desc permission:UNKNOW

04-21 18:28:25.480: E/DeviceScanActivity(12254): -->service type:PRIMARY

04-21 18:28:25.480: E/DeviceScanActivity(12254): -->includedServices size:0

04-21 18:28:25.480: E/DeviceScanActivity(12254): -->service uuid:0000ffe0-0000-1000-8000-00805f9b34fb

04-21 18:28:25.480: E/DeviceScanActivity(12254): ---->char uuid:0000ffe1-0000-1000-8000-00805f9b34fb

04-21 18:28:25.480: E/DeviceScanActivity(12254): ---->char permission:UNKNOW

04-21 18:28:25.480: E/DeviceScanActivity(12254): ---->char property:READ|WRITE_NO_RESPONSE|NOTIFY|

04-21 18:28:25.490: E/DeviceScanActivity(12254): -------->desc uuid:00002902-0000-1000-8000-00805f9b34fb

04-21 18:28:25.490: E/DeviceScanActivity(12254): -------->desc permission:UNKNOW

04-21 18:28:25.490: E/DeviceScanActivity(12254): -------->desc uuid:00002901-0000-1000-8000-00805f9b34fb

04-21 18:28:25.490: E/DeviceScanActivity(12254): -------->desc permission:UNKNOW

04-21 18:28:26.025: E/DeviceScanActivity(12254): onCharRead BLE DEVICE read 0000ffe1-0000-1000-8000-00805f9b34fb -> 00

這裡紅字是由BluetoothGattCallback的onCharacteristicRead()回調而打出Log

以下Log是PC上的串口工具通過BLE模塊發送過來，由BluetoothGattCallback的 onCharacteristicChanged()打出Log

04-21 18:30:18.260: E/DeviceScanActivity(12254): onCharWrite BLE DEVICE write 0000ffe1-0000-1000-8000-00805f9b34fb -> send data to phone

04-21 18:30:18.745: E/DeviceScanActivity(12254): onCharWrite BLE DEVICE write 0000ffe1-0000-1000-8000-00805f9b34fb -> send data to phone

04-21 18:30:19.085: E/DeviceScanActivity(12254): onCharWrite BLE DEVICE write 0000ffe1-0000-1000-8000-00805f9b34fb -> send data to phone

04-21 18:30:19.350: E/DeviceScanActivity(12254): onCharWrite BLE DEVICE write 0000ffe1-0000-1000-8000-00805f9b34fb -> send data to phone

04-21 18:30:19.605: E/DeviceScanActivity(12254): onCharWrite BLE DEVICE write 0000ffe1-0000-1000-8000-00805f9b34fb -> send data to phone

04-21 18:30:19.835: E/DeviceScanActivity(12254): onCharWrite BLE DEVICE write 0000ffe1-0000-1000-8000-00805f9b34fb -> send data to phone

04-21 18:30:20.055: E/DeviceScanActivity(12254): onCharWrite BLE DEVICE write 0000ffe1-0000-1000-8000-00805f9b34fb -> send data to phone

04-21 18:30:20.320: E/DeviceScanActivity(12254): onCharWrite BLE DEVICE write 0000ffe1-0000-1000-8000-00805f9b34fb -> send data to phone

04-21 18:30:20.510: E/DeviceScanActivity(12254): onCharWrite BLE DEVICE write 0000ffe1-0000-1000-8000-00805f9b34fb -> send data to phone

04-21 18:30:20.735: E/DeviceScanActivity(12254): onCharWrite BLE DEVICE write 0000ffe1-0000-1000-8000-00805f9b34fb -> send data to phone

04-21 18:30:21.000: E/DeviceScanActivity(12254): onCharWrite BLE DEVICE write 0000ffe1-0000-1000-8000-00805f9b34fb -> send data to phone

接下來貼出本文核心代碼：

[java] view plaincopyprint?

public class DeviceScanActivity extends&