Use Node.js DDP Client on Arduino Yun to Access Meteor Server
概述
在Arduino Yun上安装 Node.js, 并测试与 Meteor 通过 DDP Client 通讯。
所用硬件
- Arduino Yun
- SD Card（至少 2GB，我使用的是 8G ）
所用软件
PC 软件：
- Arduino IDE
- SSH Terminal（Putty / Screen）
升级 Arduino Yun固件
从网站上下载 Arduino Yun 最新的 openWRT 固件, 当前升级包的版本是 YunSysupgradeImage_v1.5.3.zip。
选用 MS-DOS 方式格式化 SD Card，将所下载的 ZIP 文件展开出的 bin 文件拷贝到 SD Card 的根目录下。
将 SD Card 插入 Arduino Yun, 并重启 Arduino Yun。正常情况下，应该能够在 Web Page 点按 “RESET” 按钮执行升级。
也可以用 SSH 登陆后，先检查一下 /mnt/sda1 目录下是否有升级文件，并执行以下命令。
# ls /mnt/sda1
openwrt-ar71xx-generic-yun-16M-squashfs-sysupgrade.bin
# run-sysupgrade /mnt/sda1/openwrt-ar71xx-generic-yun-16M-squashfs-sysupgrade.bin
- 升级完成后，选择 ArduinoYun 的初始 WIFI，并通过 Web 页面访问 192.168.240.1，设置 Arduino Yun 的网络连接。
利用 SD Card 扩展 Arduino Yun 空间
Arduino Yun 的板上存储仅有 16M，要想安装更多地东西就必须利用 SD Card 扩展磁盘空间。参考链接
重启后，通过本地局域网，SSH 到 Arduino Yun上，检查现有的分区情况。
# df Filesystem 1K-blocks Used Available Use% Mounted on rootfs 7104 364 6740 5% / /dev/root 7680 7680 0 100% /rom tmpfs 30560 148 30412 0% /tmp tmpfs 512 0 512 0% /dev /dev/mtdblock3 7104 364 6740 5% /overlay overlayfs:/overlay 7104 364 6740 5% / /dev/sda1 7746772 1008 7745764 0% /mnt/sda1通过 USB 连接 Arduino Yun，打开 Arduino IDE 上传此 ino 文件, 然后打开 Serial Monitor，在屏幕右下方选择 “Newline”, 并按照提示进行操作。下面的操作记录了我为分区方式，供参考。需要注意的是，此处输入的 4096 的意思是，将 4G 的空间保留为 /mnt/sda1 下的数据存储，剩下的空间留给根目录。整个过程需要等待几分钟。
Open the Serial Monitor and double check the dropdown menu "Newline" has been selected. This sketch will format your micro SD card and use it as additional disk space for your Arduino Yun. Please ensure you have ONLY your micro SD card plugged in: no pen drives, hard drives or whatever. Do you wish to proceed (yes/no)? yes Starting Bridge... Ready to install utility software. Please ensure your Arduino Yun is connected to internet. Ready to proceed (yes/no)? yes Updating software list... Software list updated. Installing software (this will take a while)... e2fsprogs mkdosfs fdisk rsync installed Proceed with partitioning micro SD card (yes/no)? yes Enter the size of the data partition in MB: 4096 Partitioning (this will take a while)... Micro SD card correctly partitioned Creating 'arduino' folder structure... Copying files from Arduino Yun flash to micro SD card... Enabling micro SD as additional disk space... enabled We are done! Yeah! Now press the YUN RST button to apply the changes.按下 YUN RST 后等待系统完全重启，再次检查分区情况，可以看到，Root 目录已经被放置在 /dev/sda2 下了，大小已经被扩大。
# df Filesystem 1K-blocks Used Available Use% Mounted on rootfs 3556712 120920 3257464 4% / /dev/root 7680 7680 0 100% /rom tmpfs 30560 100 30460 0% /tmp tmpfs 512 0 512 0% /dev /dev/sda2 3556712 120920 3257464 4% /overlay overlayfs:/overlay 3556712 120920 3257464 4% / /dev/sda1 4186104 12 4186092 0% /mnt/sda1
安装 Node.js
确认 Arduino Yun 可以正常联网，然后执行以下安装 Node.js， 原文参考链接
# opkg update
# opkg install node
安装完成之后，可以用以下命令检查 Node.js 安装成功
# node -e "console.log('Hello_Yun')"
Hello_Yun
Arduino Yun 可用的所有 Package 可以在这里找到。您还可以根据需要，安装更多的 Node.js 基础包，例如：
# opkg install node-serialport
# opkg install node-noble
设置 Swap 区
Arduino Yun 提供的 Node.js 包很有限，还需要通过 npm 安装更多可扩展包。但是因为 npm 所需的内存比较大，我们必须打开 Swap 才能够顺利执行，否则会报内存不足。
检查现有的 Swap 设置
# free -m total used free shared buffers Mem: 61116 31712 29404 0 8364 -/+ buffers: 23348 37768 Swap: 0 0 0SSH 登陆后，创建 Swap 分区，这一步要等比较长的时间。
# mkdir /swap # dd if=/dev/zero of=/swap/yunswapfile bs=1M count=1024 1024+0 records in 1024+0 records out设置 Swapon，此时已经可以看到 Swap 区正确创建了。
# mkswap /swap/yunswapfile # swapon /swap/yunswapfile # free -m total used free shared buffers Mem: 61116 59704 1412 0 7676 -/+ buffers: 52028 9088 Swap: 1048572 0 1048572设置启动时自动加载 Swap。重启 Arduino Yun 后，Swap 区应该正常。
# uci add fstab swap # uci set fstab.@swap[0].device=/swap/yunswapfile # uci set fstab.@swap[0].enabled=1 # uci set fstab.@swap[0].fstype=swap # uci set fstab.@swap[0].options=default # uci set fstab.@swap[0].enabled_fsck=0 # uci commit
安装 DDP Client
此时，我们再使用 npm 安装 DDP Client。我使用的 DDP Client 是 https://www.npmjs.com/package/ddp
# npm install ddp
# npm install underscore
# npm list
/root
├─┬ [email protected]
│ ├── [email protected]
│ ├── [email protected]
│ ├─┬ [email protected]
│ │ └─┬ [email protected]
│ │ └── [email protected]
│ └─┬ [email protected]
│ ├── [email protected]
│ ├─┬ [email protected]
│ │ └─┬ [email protected]
│ │ ├── [email protected]
│ │ ├── [email protected]
│ │ ├── [email protected]
│ │ └── [email protected]
│ ├── [email protected]
│ ├─┬ [email protected]
│ │ └── [email protected]
│ ├── [email protected]
│ ├─┬ [email protected]
│ │ └── [email protected]
│ ├─┬ [email protected]
│ │ ├── [email protected]
│ │ ├── [email protected]
│ │ ├── [email protected]
│ │ └── [email protected]
│ ├─┬ [email protected]
│ │ ├── [email protected]
│ │ ├── [email protected]
│ │ └── [email protected]
│ ├── [email protected]
│ ├── [email protected]
│ ├─┬ [email protected]
│ │ └── [email protected]
│ ├── [email protected]
│ ├── [email protected]
│ ├── [email protected]
│ ├── [email protected]
│ ├── [email protected]
│ └── [email protected]
└── [email protected]
使用 DDP Client 访问 Meteor
下面的参考实现展示了如何用 DDP Client 与 Meteor 交互。
var DDPClient = require("ddp"),
_ = require('underscore');
var ddpclient = new DDPClient({
// url: 'ws://192.168.199.240:3000/websocket'
url: 'ws://mcotton-01.chinacloudapp.cn/websocket'
});
var useremail = "[email protected]";
var pwd = "123456";
var user_id = null, token = null;
var appkit_weather_station, myappkit_weather_station, my_app_kit_id;
var data_observer, control_observer;
/*
* Connect to the Meteor Server
*/
ddpclient.connect(function (error, wasReconnect) {
// If autoReconnect is true, this callback will be invoked each time
// a server connection is re-established
if (error) {
console.log("DDP connection error!");
return;
}
if (wasReconnect) {
console.log("Reestablishment of a connection.");
}
console.log("connected!");
ddpclient.call("login", [
{user: {email: useremail}, password: pwd}
], function (err, result) {
console.log(result);
user_id = result.id;
token = result.token;
if (token) {
console.log("Logined!", user_id, token);
//var observer = ddpclient.observe("appkits");
/*
* Subscribe to a Meteor Collection
*/
ddpclient.subscribe(
"appkits", // name of Meteor Publish function to subscribe to
[], // any parameters used by the Publish function
function () { // callback when the subscription is complete
console.log("appkits all ==> ", ddpclient.collections.appkits);
appkit_weather_station = _(ddpclient.collections.appkits).findWhere({name: 'Weather Station'});
console.log("appkits weather_station ==> ", appkit_weather_station);
console.log("appkits weather_station id ==> ", appkit_weather_station._id);
// Create myAppKit
var myAppKit = ddpclient.call(
'myAppKitInsert',
[{
name: 'My Weather Station',
app_kit_id: appkit_weather_station._id
}],
function (err, result) {
console.log('myAppKitInsert, error: ' + error);
console.log('myAppKitInsert, result: ' + result._id);
my_app_kit_id = result._id;
/*
* Subscribe to a Meteor Collection
*/
ddpclient.subscribe(
"myappkits", // name of Meteor Publish function to subscribe to
[user_id], // any parameters used by the Publish function
function () { // callback when the subscription is complete
console.log("myappkits all ==> ", ddpclient.collections.myappkits);
console.log("appkit_weather_station id ==> ", appkit_weather_station._id);
myappkit_weather_station = _(ddpclient.collections.myappkits).filter({_id: my_app_kit_id});
console.log("myappkits weather_station ==> ", myappkit_weather_station);
}
);
ddpclient.subscribe(
"dataevents", // name of Meteor Publish function to subscribe to
[user_id], // any parameters used by the Publish function
function () { // callback when the subscription is complete
console.log("dataevents all ==> ", ddpclient.collections.dataevents);
}
);
ddpclient.subscribe(
"controlevents", // name of Meteor Publish function to subscribe to
[user_id], // any parameters used by the Publish function
function () { // callback when the subscription is complete
console.log("controlevents all ==> ", ddpclient.collections.controlevents);
}
);
/*
* observe DataEvents
*/
data_observer = ddpclient.observe("dataevents");
data_observer.added = function (id) {
console.log("[ADDED] to " + data_observer.name + ": " + id);
var event = _(ddpclient.collections.dataevents).findWhere({_id: id});
console.log("[ADDED] dataevents ", event)
};
/*
* observe ControlEvents
*/
control_observer = ddpclient.observe("controlevents");
control_observer.added = function (id) {
console.log("[ADDED] to " + control_observer.name + ": " + id);
var event = _(ddpclient.collections.controlevents).findWhere({_id: id});
console.log("[ADDED] controlevents ", event)
};
/*
* Send new Control Event to Server
* */
var newControlEvent = ddpclient.call(
'controlEventInsert',
[{
my_app_kit_id: my_app_kit_id,
control_name: "Status",
control_value: "true"
}],
function (err, result) {
console.log('controlEventInsert, error: ' + error);
console.log('controlEventInsert, result: ' + result._id);
});
}
);
}
);
}
});
////Debug information
//
//ddpclient.on('message', function (msg) {
// console.log("ddp message: " + msg);
//});
/*
ddpclient.on('socket-close', function (code, message) {
console.log("Close: %s %s", code, message);
});
ddpclient.on('socket-error', function (error) {
console.log("Error: %j", error);
});
*/
// close
setTimeout(function () {
// observer.stop();
ddpclient.close();
}, 5000);
});
代码地址
https://github.com/iascchen/arduino_study/tree/master/src/yun_ddp
转载请注明出处
Author : iascchen(at)gmail(dot)com
Date : 2015-6-3
Github : https://github.com/iascchen/arduino_study
新浪微博 : @问天鼓