Coding365 2018/12/01

1. CoAP 與 LwM2M 應用實作
易弼仁

2. 目標
1
ATMega32u4
UART
MT7688
節點開發環境準備1
LwM2M Client (coap-node)
LwM2M Server (coap-shepherd)
register() ind
readReq()
writeReq()
組織機器網路與操作遠端節點3
LwM2M Client (coap-node)
SmartObject
設計機器節點2
LwM2M
Server Client
確認 Linkit 7688 Duo 中已有程式碼與 fermata、smartobject 和 coap-node模組

3. Reset 按鈕與狀態燈號參照表
2

4. 智慧物件
3

5. 應用層統一資料模型
4
訊息／數據
的意義是什麼？
屬性 命令 行為
Physical
Data Link
Network
Transport
> 230 models
2016 (OIC@2014)
51 models
2008
5 Schemas
2015

6. 智慧物件 Smart Object
5
Object
oid = 3303
rid = 5700
Resources
rid = 5701
rid = 5605
Temperature Sensor
Boilerplate
Create instance with an iid
Temperature Sensor
Entity #1
oid = 3303
rid = 5700
rid = 5701
rid = 5605
iid = 1
Object Instance
value
value
value
oid = 3303
rid = 5700
rid = 5701
rid = 5605
iid = 0
Object Instance
value
value
value
Temperature Sensor
Entity #0
IPSO Alliance & IPSO Model
└ 對真實世界的物件資料模型進行標準化
└ 已定義 51 種 Smart Objects，增加中
└ 採用階層化資料模型
└ Object, Object Instance, Resource

7. 請花幾分鐘閱讀
6
溫度感測器的模型
└ https://github.com/AllSmartObjects/smartobject/blob/master/docs/templates.md#tmpl_temperature
電燈的模型
└ https://github.com/AllSmartObjects/smartobject/blob/master/docs/templates.md#tmpl_lightCtrl
SmartObject 模組使用入門
└ Overview: https://github.com/AllSmartObjects/smartobject#1-overview
└ Usage: https://github.com/AllSmartObjects/smartobject#3-usage
SmartObject 的存取介面
└ Read: https://github.com/AllSmartObjects/smartobject#API_read
└ Write: https://github.com/AllSmartObjects/smartobject#API_write
1 mins
1 mins
6 mins
5 mins

8. smartobject 模組
7
APIs 說 明
new SmartObject() 建立 SmartObject 實例
.init() 建立並初始化一個物件實例 (Object Instance)
.read() 讀取 SmartObject 實例中資源的值
.write() 寫入 SmartObject 實例中資源的值
.dump() 讀取 SmartObject 實例中所有資源的值
smartobject 模組重要 APIs 說明

9. 初始化你的智慧物件專案
8
開一個專案資料夾
進入資料夾
npm init 初始化專案
安裝所需的第三方模組
$ mkdir smart-iot-app
$ cd smart-iot-app
$ npm init
$ npm install smartobject --save
啟動新專案的制式步驟
Smart Object 專案
/smart-iot-app
/node_modules
/lib
- rboard.js
- vboard.js
- smart-obj.js
- package.json
- index.js
(前面已經做好)

10. 製作 Smart Object
9
var rboard = require('./rboard'),
vboard = require('./vboard'),
SmartObject = require('smartobject');
var so = new SmartObject({
arduino: rboard.arduino
});
so.init('temperature', 0, {
// < rid = 5700, R, Float >
sensorValue: {
read: function (cb) {
return vboard.fooBus.read(cb);
}
},
// < rid = 5701, R, String >
units: 'C'
});
so.init('lightCtrl', 0, {
// < rid = 5850, RW, Boolean { 0: off, 1: on } >
onOff: {
read: function (cb) {
return rboard.gpio.read(13, cb);
},
write: function (value, cb) {
return rboard.gpio.write(13, value, cb);
}
}
});
module.exports = so;
6 mins/lib/smart-obj.js
請在專案資料夾底下開新檔 /lib/smart-obj.js

11. index.js
10
var mySo = require('./lib/smart-obj');
mySo.hal.arduino.on('ready', function () {
console.log('rboard ready!');
// toggle the LED
setInterval(function () {
mySo.read('lightCtrl', 0, 'onOff', function (err, onOff) {
mySo.write('lightCtrl', 0, 'onOff', onOff ? 0 : 1, function (err, status) {
console.log('LED Status: ' + (status ? 'ON' : 'OFF'));
});
});
}, 2000);
// poll the sensor
setInterval(function () {
mySo.read('temperature', 0, 'sensorValue', function (err, value) {
console.log('Sensor value: ' + value + ' C');
});
}, 3000);
});
6 minsindex.js
# node index.js // 觀察結果是否與上個應用相同
應用程式的進入點 (其他常見的進入點名稱還有 main.js 或 app.js)

12. 當溫度超過 25 度就亮燈
11
var mySo = require('./lib/smart-obj');
// poll the sensor
mySo.hal.arduino.on('ready', function () {
console.log('rboard ready!');
setInterval(function () {
mySo.read('temperature', 0, 'sensorValue', function (err, value) {
console.log('Sensor value: ' + value + ' C');
if (value > 25) {
mySo.write('lightCtrl', 0, 'onOff', 1, function (err, status) {
console.log('Temp > 25 C, LED ON');
});
} else {
mySo.write('lightCtrl', 0, 'onOff', 0, function (err, status) {
console.log('Temp <= 25 C, LED OFF');
});
}
});
}, 3000);
});
3 minsindex.js
# node index.js

13. CoAP
12

14. CoAP
13
特性
└ The Constrained Application Protocol
└ 封包 overhead 較輕，標頭僅有 4 bytes
└ 專為 M2M 應用打造
└ 使用 coap:// 協定，易於和 HTTP 結合
└ 基於 UDP
└ 支援 GET, POST, PUT, DELETE 請求方法
└ 支援 URI、加解密與認證、discovery 功能
Proxy
HTTP
HTTP
CoAP
CoAP
Internet Constrained Environment
REST
Constrained Link
IP
UDP
CoAP
Web Resources
CoAP Stack
為資源受限的裝置所量身訂製的 RESTful 協定

15. Web 世界的資源命名
14
Universal Resource Locator (URL)
http:// www.example.com :8080 /sensors ?id=light
PortScheme Authority Path Query
Resource
HTTP
TCP
IP
Ethernet Link
DNS
2001:dead:beef::1

16. Web 世界的資源命名
15
Universal Resource Locator (URL)
coap:// www.example.com :5683 /sensors ?id=light
PortScheme Authority Path Query
Web Resources
CoAP
UDP
IP
Constrained Link
DNS
2001:dead:beef::1

17. LwM2M
16

18. LwM2M
17
輕量型機器對機器協定：統一管理介面
Machine ServerBootstrap Server
Machine Network Management Layer (REST Interface)
register deregister update read write
write attrs execute create delete observe
bootstrap
notify
end-nodes

19. LWM2M URLs
18
是不是覺得很眼熟呢?
/{object}/{instance}/{resource}
/3303/0/5700 (= /temperature/0/sensorValue)
http://www.example.com/myhouse/{object}/{instance}/{resource}
http://www.example.com/myhouse/3303/0/5700
http://www.example.com/myhouse/temperature/0/sensorValue

20. coap-shepherd 與 coap-node
19
提供簡單的方式建立和管理 LwM2M 網路

21. 實作：CoAP 機器節點
20

22. 應用架構
21
ATMega32u4
UART
MT7688
節點開發環境準備1
LwM2M Client (coap-node)
LwM2M Server (coap-shepherd)
register() ind
readReq()
writeReq()
組織機器網路與操作遠端節點3
LwM2M Client (coap-node)
SmartObject
設計機器節點2
LwM2M
Server Client

23. 機器網路架構
•
22
CoAP Machine Nodes
CoAP Machine Server
Temperature Sensor Light Control
REST, CoAP, WS, TCP/IP, …

Device Tier
(Edge Nodes)
Gateway Tier
User Tier
Cloud Tier
HTTP Server (Proxy)
REST, MQTT,
WS, TCP/IP, …

24. CoAP Machine Server：Leshan
23
借用 CaAP Machine Server JAVA 的實作來測試：Leshan Server Demo
待會 CoAP 要註冊的位址：
leshan.eclipse.org

25. 節點專案看起來的樣子
24
CoAP 機器節點
/coap-devices
/node_modules
/lib
- rboard.js
- vboard.js
- package.json
- cnode1.js
- cnode2.js
(前面已經做好)

26. coap-node 模組
25
APIs 說 明
new cnode(deviceName, smartobject) 建立一個 Cnode 實例
.register(address, port, callback) 發送註冊請求給 server
.deregister(callback) 發送取消註冊請求給 server
Events 說 明
'registered’ registered 事件監聽器，接收 Cnode 註冊完成通知
coap-node 模組重要 APIs 說明

27. 準備 CoAP Machine Nodes
26
我們有一個溫度感測器跟一顆 LED 燈，這裡先做溫度感測器的節點 cnode1.js
var vboard = require('./lib/vboard')
CoapNode = require('coap-node'),
SmartObject = require('smartobject');
var cnode1,
soTemp = new SmartObject({
arduino: vboard.arduino
});
soTemp.init('temperature', 0, {
sensorValue: {
read: function (cb) {
return vboard.fooBus.read(cb);
}
},
units: 'C'
});
cnode1 = new CoapNode('my_client_id_cnode001', soTemp);
cnode1.on('registered', function () {
console.log('registered');
});
cnode1.register('leshan.eclipse.org', 5683, function (err, msg)
{
if (err) {
console.log(err);
} else {
if (msg.status !== '2.01') {
setTimeout(startRegister, 5000);
}
}
});
module.exports = cnode1;
cnode1.js
Ref: https://github.com/PeterEB/coap-node/wiki#4-usage

28. 讓節點加入網路
27
設定 7688 為 Station Mode，連上網際網路
執行 $ node cnode1.js，並測試看看是否讀到溫度值

29. 製作另一個節點：cnode2.js(I)
28
var rboard = require('./lib/rboard'),
CoapNode = require('coap-node'),
SmartObject = require('smartobject');
var cnode2,
soLight = new SmartObject({
arduino: rboard.arduino,
ledPinNum: 13
});
soLight.init('lightCtrl', 0, {
onOff: {
read: function (cb) {
var hal = this.parent.hal;
return rboard.gpio.read(hal.ledPinNum, cb);
},
write: function (value, cb) {
var hal = this.parent.hal;
return rboard.gpio.write(hal.ledPinNum, value, cb);
}
}
});
cnode2.js

30. 製作另一個節點：cnode2.js(II)
29
cnode2 = new CoapNode('my_client_id_cnode002', soLight);
cnode2.on('registered', function () {
console.log('registered');
});
soLight.hal.arduino.on('ready', function () {
console.log('rboard ready!');
cnode2.register('leshan.eclipse.org', 5683, function (err, msg) {
if (err) {
console.log(err);
} else {
if (msg.status !== '2.01') {
setTimeout(startRegister, 5000);
}
}
});
});
module.exports = cnode2;
cnode2.js
Ref: https://github.com/PeterEB/coap-node/wiki#4-usage

31. 讓節點加入網路
30
執行 $ node cnode2.js，測試看看除了讀取到 LED 狀態外，還可以做什麼…

32. 實作：CoAP 伺服器
31

33. 機器網路架構
•
32
CoAP Machine Nodes
CoAP Machine Server
Temperature Sensor Light Control
REST, CoAP, WS, TCP/IP, …

Device Tier
(Edge Nodes)
Gateway Tier
User Tier
Cloud Tier
HTTP Server (Proxy)
REST, MQTT,
WS, TCP/IP, …

34. 33
ATMega32u4
UART
MT7688
節點開發環境準備1
LwM2M Client (coap-node)
LwM2M Server (coap-shepherd)
register() ind
readReq()
writeReq()
組織機器網路與操作遠端節點3
LwM2M Client (coap-node)
SmartObject
設計機器節點2
LwM2M
Server Client

35. 節點專案看起來的樣子
34
CoAP 機器節點
/coap-server
/node_modules
- package.json
- app.js
$ npm install coap-shepherd
於電腦終端機執行指令 $ npm install coap-shepherd 安裝模組

36. 35
Server APIs 說 明
new CShepherd() 建立 CShep 實例
.start() 啟動 coap-shepherd，啟動完成後發射 ready 事件
.permitJoin() 允許或禁止周邊 client 裝置加入網路
.find() 搜尋已入網之 client device 實例，可對其進行讀寫操作
Server Events 說 明
'ready' ready 事件監聽器，接收 CShep 啟動完成通知
'ind' ind 事件監聽器，接收 client 相關事件通知 (如裝置入網、離網等)
Client APIs 說 明
.readReq() 讀取遠端 client 裝置的資源
.writeReq() 將值寫入到遠端 client 裝置的資源中
.observeReq() 訂閱遠端 client 裝置的資源
coap-shepherd 模組重要 APIs 說明

37. 36
var cserver = require('coap-shepherd');
cserver.on('ready', function () {
console.log('>> coap-shepherd server start!');
console.log('>> Permit devices joining for 180 seconds');
cserver.permitJoin(180);
});
cserver.start(function (err) {
if (err)
console.log(err);
});
app.js

38. 37
cserver.on('ind', function (msg) {
switch (msg.type) {
case 'devIncoming':
devIncomingHandler(msg);
break;
case 'devStatus':
devStatusHandler(msg);
break;
case 'devNotify':
devNotifyHandler(msg);
break;
default:
// Not deal with other msg.type in this example
break;
}
});
app.js

39. 38
function devIncomingHandler(msg) {
var cnode = msg.cnode;
if (cnode.clientName === 'my_client_id_cnode001') {
cnode.readReq('temperature/0/sensorValue', function (err, rsp) {
if (!err)
console.log('>> Current temperature value at machine: ' + rsp.data);
});
}
}
app.js

40. 39
function devStatusHandler(msg) {
var cnode = msg.cnode;
if (cnode.clientName === 'my_client_id_cnode001' && msg.data === 'online') {
// setting for notification of led state reporting
cnode.observeReq('temperature/0/sensorValue', function (err, rsp) {
console.log('>> Temperature observation starts: ' + rsp.status);
});
}
}
app.js

41. 40
function devNotifyHandler(msg) {
var data = msg.data,
node = cserver.find('my_first_node');
if (data && data.path === ‘/temperature/0/sensorValue') {
console.log(‘>> Temperature value at machine changed: ' + data.value);
}
}
app.js

42. 修改註冊 IP 位址
41
修改 cnode1.js 中的 IP 位址為 coap-shepherd 所在電腦的 IP 位置
// ...略
cnode1.register('192.168.1.196', 5683, function (err, msg) {
if (err) {
console.log(err);
} else {
if (msg.status !== '2.01') {
setTimeout(startRegister, 5000);
}
}
});
module.exports = cnode1;
cnode1.js
$ ifconfig
於電腦終端機執行指令 $ ifconfig 取得 IP 位置

43. 執行測試
於電腦終端機執行指令 $ node app.js，
於 Linkit 7688 Duo 執行指令$ node cnode1.js
觀察電腦終端機是否有印出溫度值。
42
$ node app.js
$ node cnode1.js

44. 修改溫度值回傳時間
43
function devStatusHandler(msg) {
var cnode = msg.cnode;
if (cnode.clientName === 'my_client_id_cnode001' && msg.data === 'online') {
// setting for notification of led state reporting
cnode.writeAttrsReq('temperature/0/sensorValue', { pmax: 10 }, function (err, rsp) {
console.log('>> Temperature writeAttrs starts: ' + rsp.status);
cnode.observeReq('temperature/0/sensorValue', function (err, rsp) {
console.log('>> Temperature observation starts: ' + rsp.status);
});
});
}
}
app.js

45. Thank you
44