Skip to content

Latest commit

 

History

History
executable file
·
223 lines (151 loc) · 10.1 KB

helper_BLE.md

File metadata and controls

executable file
·
223 lines (151 loc) · 10.1 KB
Raw

BLE

GitHub license GitHub stars GitHub forks GitHub issues GitHub watchers

1. Overview

You can call Bluetooth Low Energy, Bluetooth LE, BLE.

Bluetooth Low Energy is a wireless, low-power personal area network that operates in the 2.4 GHz ISM band. Its goal is to connect devices over a relatively short range. BLE was created with IoT applications in mind, which has particular implications for its design. For example, IoT devices tend to be constrained and require extended battery use, so BLE favors low power consumption over continuous data transfer. In other words: when not in use, it goes into sleep mode to conserve energy.

1.1. Device rules

It is asymmetry.

Neither two central nor two peripheral devices can talk to each other. Communication is only possible between a central and a peripheral device.

A. Central Device

B. Peripheral Device

which has limited functionality.

1.2. Server or Client

The device mode should not be confused with its Generic Attribute Profile (GATT), where a device can either act as a server or a client.

這邊提到的就是在設備定義中有 Central 和 Peripheral 兩種。但是在功能面中，GATT 可以讓每一個設備同時具備 Server 和 Client 的 “功能”（為什麼不用“角色”這名詞，最近常發生與非理工的人討論 Server 和 Client時，他們常常搞不清傳輸是雙向的，只是觸發的時間有先後。 ）。

1.3. BLE vs Bluetooth Classic

SIG introduced Bluetooth Low Energy in its 2010 Bluetooth 4.0 specification (with later, 2016 Bluetooth 5 specification, being devoted exclusively to BLE).

Its main focus was on the growing market of health- and fitness-related devices and smart home and indoor location.

Bluetooth Classic BLE
傳輸 連續且長時間傳輸 短時間的小封包傳輸
功耗 1
1 W		 1/100
0.01~0.50 W
傳輸速率 1~3 Mbit/s 125 Kbit/s~2 Mbit/s
距離 100m <100m

2. Software Architecture

flowchart TD
	subgraph OS
    subgraph Host[Host]
     GAP[GAP - Generic Access Profile]
     SM[SM - Security Manager]
     GATT[GATT - Generic Attribute Profile]
     ATT[ATT - Attribute Protocol]
     L2CAP[L2CAP - Logical Link Control and Adaption Protocol]
    end
		subgraph HCI[HCI - Host Controller Interface]
			HCIDriver[Driver - UART / USB / SDIO / 3-Wire UART]
		end
	end

	subgraph Controller[Controller]
		LL[LL - Link Layer]
		PHY[PHY - Physical Layer]
	end

	classDef yellow fill:#FFFFCC
	classDef pink fill:#FFCCCC
	classDef blue fill:#0000FF
	classDef lightblue fill:#ADD8E6

	Host <--> HCI <--> Controller
Loading

這邊為什麼多加一個 OS group，因為所有模組或是晶片都是嫁接在一個作業系統上，不管是 Linux 或是 RTOS，才會生出一個 UART 或 USB 接口。

很多文件和網頁都省略了作業系統，其實 HCI 這層就等同於 Driver；當我們看不到連上任何接口時，是要往那個地方送資料啊。另外 Host 也是一個麻煩處，裏面包含了加解密、資料格式定義等，是要每位設備開發者都要先把 BLE 規格讀過一遍才去開發嗎？

這邊就有些微詞，當你身為一個設備的開發者，拿到晶片廠的晶片，還要去幫晶片廠寫 HCI 和 Host Layer嗎？

在 Linux 之上有 BlueZ，這真的是造福大眾，由衷的感謝！

3. Network Topology

在此網頁內容中，可以很簡單的知道相關訊息。

3.1. Advertising and Scan Response Data

3.2. Broadcast

3.2. Connected

3.2.1. GATT Transactions

A. Profile - Services and Characteristics (Profiles Overview)

Appendix

I. Study

I.1. BLE（16）—— BLE 层次（HOST/HCI/Controller）

I.2. Everyone is using Bluetooth Low Energy – should you?

I.3. [Day 16] BLE 封包監聽工具(Packet Sniffer)

I.4. 藍芽低功耗介紹

I.5. iBeacon詳細指南

I.6. BluetoothProfile

I.7. 查看電腦使用哪個藍牙版本

連結管理員通訊協定版本 (LMP) 藍牙核心規格
LMP 0 藍牙核心規格 1.0b (已淘汰)
LMP 1 藍牙核心規格 1.1 (已淘汰)
LMP 2 藍牙核心規格 1.2 (已淘汰)
LMP 3 藍牙核心規格 2.0 + EDR (已淘汰)
LMP 4 藍牙核心規格 2.1 + EDR (已過時，將淘汰)
LMP 5 藍牙核心規格 3.0 + HS (已過時，將淘汰)
LMP 6 藍牙核心規格 4.0
LMP 7 藍牙核心規格 4.1
LMP 8 藍牙核心規格 4.2
LMP 9 藍牙核心規格 5.0
LMP 10 藍牙核心規格 5.1
LMP 11 藍牙核心規格 5.2

II. Debug

III. Glossary

ADV, Advertising

BLE 裝置透過 Advertising 告知周邊 BLE 裝置自己的存在。

所使用的頻率 channel 37 (2402 MHz)、channel 38 (2426 MHz)、 和 channel 39 (2480 MHz)。

BAS, Battery Service

The Battery Service exposes the battery level and other information for a battery within a device.

Core Specification

This specification defines the technologies required to create interoperable Bluetooth devices.

DIS, Device Information Service

This service exposes manufacturer and/or vendor information about a device.

DIS_SPEC_V11r00.pdf

HIDS, Human Interface Service

This service exposes HID reports and other HID data intended for HID Hosts and HID Devices.

HIDS_SPEC_V10.pdf

HOGP, HID OVER GATT PROFILE

This profile defines how a device with Bluetooth low energy wireless communications can support HID services over the Bluetooth low energy protocol stack using the Generic Attribute Profile.

HRS, Heart Rate Service

This profile enables a Collector device to connect and interact with a Heart Rate Sensor for use in fitness applications.

HRP_V10.pdf

HRS_SPEC_V10.pdf

GAP, Generic Access Profile

設備的的配置文件。定義設備的角色 Central or Peripheral。用於 Advertising之中。

BLUETOOTH SPECIFICATION Version 5.0 | Vol 3, Part C

GATT, Generic Attribute Profile

定義了設備的主/從關係。

BLUETOOTH SPECIFICATION Version 5.0 | Vol 3, Part G

iBeacon

From welcoming people as they arrive at a sporting event to providing information about a nearby museum exhibit, iBeacon opens a new world of possibilities for location awareness, and countless opportunities for interactivity between iOS devices and iBeacon hardware.

IV. Tool Usage

Author

Created and designed by Lanka Hsu.

License

HelperX is available under the BSD-3-Clause license. See the LICENSE file for more info.