Eric Liang #
Date:2015/06/16
Outline
 M2M Communication for ptt 地震文
 MQTT
 mbed (client ) + Raspberry pi (broker)
 HTTP
 Mbed (client ) + MCS (MediaTek Cloud Sandbox )
 CoAP
 Mbed ( CoAP Server ) + Firefox ( Copper client )
M2M Communication for PTT 地震文
Raspberry Pi 2
mbed K64F + FXOS8700
mbde Arch Pro + MPU 6050
mbde Arch Pro + MPU 6050
MQTT
 輕量級訊息佇列 ( message queueing ) 傳輸協定
 非同步訊息(事件) 通訊模式
 Low overhead ( 2 bytes header) 適合應用於低頻寬網路
 支持各種流行編程語言（包括 C，Java，Ruby，Python...）& Client 容易使用
 發佈 (Publish) / 訂閱 (Subscribe) 模式，簡化應用程序的開發
 發佈 和 訂閱 傳送資料透過 標題 (Topics) 訊息佇列( message queues )
 底層協定為TCP/IP
 提供三種不同消息傳遞等級，讓消息能按需到達目的地，適應在不穩定工作的
網絡傳輸 (Wireless Network disruptions)
MQTT (Cont’d)
Client C
“temperature”
= “22.5”
subscribe “temperature”
Broker
publish “temperature” “22.5”
Client A
“temperature”
subscribe “temperature”
= “22.5”
Client B
Refer to:
http://isplanet.dyndns-office.com:8081/wiki/index.php/Message_Queuing_Telemetry_Transport
MQTT Client + mbed
MQTT Client + mbed (Cont’d)
MQTT Client + mbed (Cont’d)
MQTT + RPi
 Install the mosquitto 1.4.1 on Raspberry Pi
 Run the Broker Server
 Subscribe – by Python-mosquitto
 Refer to
http://isplanet.dyndns-office.com:8081/wiki/index.php/Message_Queuing_Telemetry_Transport
MQTT Demo ( mbed + RPi )
 Topic: sen/g-sensor
 Message: Name X Y Z G
 Eric 0.0012 0.002 0.0001 0.001
HTTP ( Cont’d )
 Web Open IoT Cloud Architecture
 Physical Web: WoT ( Web of Things ) + REST API
 https://www.mokoversity.com/post/%E5%BE%9E%20Google%20%E7%9A%84%20
Physical%20Web%20%E8%A8%88%E7%95%AB%E8%A7%A3%E8%AE%80%20IoT
%20%E6%8A%80%E8%A1%93%E8%B6%A8%E5%8B%A2
HTTP
 Apache / IIS / nginx / Tomcat / Node.js
 GET / POST / PUT / DELETE
 200 OK / 201 Create /
 400 Bad Request / 401 Unauthorized / 404 Not Found
 500 Internal Server Error / 501 Not Implemented
HTTP Client + mbed
HTTP Client + mbed / MCS
 mediaTek Cloud Sandbox
 mbed HTTP Client
 Demo
CoAP ( Constrained Application Protocol )
 M2M Protocol
 CoAP over UDP ( Sever default port: 5683 )
 The smallest size is 4 Bytes ( Header only )
 Suit for Small Device ( 256KB Flash 32KB RAM CPU 20MHz)
 Request / Response ( like HTTP )
 Resource Discover ( by URI: .well-known/core )
 GET /.well-known/core
 Response:
<sensors/temp>;sz=512;title=Temperature Sensor;ct=50
CoAP Header
 Ver: CoAP version, 01 ( like HTTP1.0 / HTTP1.1 )
 T: Confirmable (0), Non-confirmable (1), Acknowledgement (2), or Reset (3)
 TKL: Token Length (0-8 bytes)
 Code: Request / Reply Code. 2.xx, 4.xx, 5.xx
 Message ID: Used to detect message duplication.
 Token: is used to match a response with a request.
 Options: like HTTP Header. Host: xx, URI, Request parameter or content-type
 11111111: (0xFF) indicates the end of options and the start of the payload.
 Payload: Data Content
CoAP Request /Response Code
 Request
 0.01 GET
 0.02 POST
 0.03 PUT
 0.04 DELETE
 Response
 2.04 Changed
 2.05 Content (HTTP 200 OK )
 4.00 Bad Request ( HTTP 400 )
 4.01 Unauthorized ( HTTP 401)
 5.00 Internal Server Error ( HTTP 500 )
 5.01 Not Implemented ( HTTP 501 )
CoAP Option Format
 1’s Option Delta = 11 => Uri-Path (11), \sen\temperature
 2’s Option Delta = 1, => 1+11 Content-Format (12), text/plain, application/json
 3’s Option Delta = 3, => 3+1+11 Uri-Query (15), ?value1=1&value2=2
Example of CoAP
 CoAP Client “GET” the temperature value from Server
 CoAP URI: coap://www.server.com/temperature
GET
Reply
CoAP ( WebIOPi + Copper )
 Installer the WebIOPi on Rpi
 Download the WebIOPi (WebIOPi-0.7.1.tar.gz)
http://sourceforge.net/projects/webiopi/files/
 $ tar xvzf WebIOPi-x.y.z.tar.gz
 $ cd WebIOPi-x.y.z
 $ sudo ./setup.sh
 $ sudo webiopi -d -c /etc/webiopi/config
 Web’s id:password: webiopi/raspberry
 Copper ( Mozilla Plug-in Module )
 Refer to
http://blog.csdn.net/xukai871105/article/details/20799551
WebIOPi + Copper ( Demo)
 Set the Pin4 as digital out
 http://ip:port/GPIO/4/function/out
 Set GPIO 4 by CoAP protocol
 coap://ip:5683/GPIO/4/value/1
WebIOPi + Copper ( Cont’d)