Node-REDで温度などの時系列データをCSVファイルに保存する

はじめに

今回はTibbo-Piを使用して、温度や照度を取得します。
Node-REDを使い、そのデータを時系列でCSVファイルに保存していきます。

例えば、そのローカルに保存したCSVファイルをクラウド(Dropboxなど)へアップすると、
遠隔やスマホからデータを確認したり、ユーザと共有したりすることができます。
記事参考：Node-REDでCSVファイルをDropboxで共有する

温度情報をCSVファイルに保存する

まずはTibbo-Piから温度の情報を取得し、時系列にCSVファイルを保存します。
Tibbo-Piに温度センサー(#29)を設置します。

Node-REDで温度情報が取れるか、まずは確認してみましょう。
以下のようにデバッグタブに温度を出力するようにしてみます。

injectノードをクリックすると、デバッグタブに温度が表示されます。

この情報をCSV出力してみます。
CSVノードを配置します。

設定はそのままにします。

次にfileノードを使用します。

設定は以下のようにしました。
ファイル名は可変でも指定はできますが、ここでは固定で設定しました。（後述）
また、「メッセージの入力のたびに改行を追加」のチェックを外します。

フロー全体は以下のような感じです。
functionノードも使用し、CSVのデータに日付を追加します。

CSVデータ作成というfunctionノードの中身は以下になります。
現在日付を追加しているだけです。

var now = new Date();
var nowStr =
    "" + now.getFullYear() +
    "/" + ('0' + (now.getMonth() + 1)).slice(-2) +
    "/" + ('0' + now.getDate()).slice(-2) +
    " " + ('0' + now.getHours()).slice(-2) +
    ":" + ('0' + now.getMinutes()).slice(-2) +
    ":" + ('0' + now.getSeconds()).slice(-2);

msg.payload = {
    // 日付
    date: nowStr,
    // 温度
    temp:msg.payload
}

return msg;

var now = new Date();

var nowStr =

"" + now.getFullYear() +

"/" + ('0' + (now.getMonth() + 1)).slice(-2) +

"/" + ('0' + now.getDate()).slice(-2) +

" " + ('0' + now.getHours()).slice(-2) +

":" + ('0' + now.getMinutes()).slice(-2) +

":" + ('0' + now.getSeconds()).slice(-2);

msg.payload = {

// 日付

date: nowStr,

// 温度

temp:msg.payload

}

return msg;

これで完成です。実行してみましょう。
以下のファイルが作成され、中身は「日付」「温度」のようになっていることを確認してください。
クリックするたびにデータが追記されていきます。

/home/pi/csv_sample/20180901.csv

複数のセンサー情報を取得する方法

今度は、温度と照度、湿度のデータを同時に３つ取得し、時系列にCSVに出力します。
まずはTibbo-Piに、#28 照度センサ、#29 温度センサ、#30 温度/湿度センサを配置します。

Node-REDで、３つのデータが揃ったら、１行のCSVを出力します。
Node-REDのノードはこのように配置します。

詳しくは、最後にフローをjsonで公開していますので、読み込んで確認してください。
各センサーのデータを取得し、すべてのデータが揃った場合に、CSVデータ作成へ進みます。

フラグセット

msg.num = 1;
return msg;

1 2	msg.num = 1; return msg;

msg.num = 2;
return msg;

1 2	msg.num = 2; return msg;

msg.num = 3;
return msg;

1 2	msg.num = 3; return msg;

センサーデータ取得

var light = context.get("ctx_light")||"";
var temp = context.get("ctx_temp")||"";
var humd = context.get("ctx_humd")||"";

if(msg.num === 1){
    light = msg.payload;
}else if(msg.num === 2){
    temp = msg.payload;
}else if(msg.num === 3){
    humd = msg.payload.humd;
}

if(light !== "" && temp !== "" && humd !== ""){
    msg.payload = {
        temp: temp,
        light: light,
        humd: humd
    };
    
    context.set("ctx_light","");
    context.set("ctx_temp","");
    context.set("ctx_humd","");
    return msg;
    
}else{
    
    context.set("ctx_light", light);
    context.set("ctx_temp", temp);
    context.set("ctx_humd", humd);
    return null;
    
}

var light = context.get("ctx_light")||"";

var temp = context.get("ctx_temp")||"";

var humd = context.get("ctx_humd")||"";

if(msg.num === 1){

light = msg.payload;

}else if(msg.num === 2){

temp = msg.payload;

}else if(msg.num === 3){

humd = msg.payload.humd;

}

if(light !== "" && temp !== "" && humd !== ""){

msg.payload = {

temp: temp,

light: light,

humd: humd

};

context.set("ctx_light","");

context.set("ctx_temp","");

context.set("ctx_humd","");

return msg;

}else{

context.set("ctx_light", light);

context.set("ctx_temp", temp);

context.set("ctx_humd", humd);

return null;

}

CSVデータ作成

var now = new Date();
var nowStr =
    "" + now.getFullYear() +
    "/" + ('0' + (now.getMonth() + 1)).slice(-2) +
    "/" + ('0' + now.getDate()).slice(-2) +
    " " + ('0' + now.getHours()).slice(-2) +
    ":" + ('0' + now.getMinutes()).slice(-2) +
    ":" + ('0' + now.getSeconds()).slice(-2);

msg.payload = {
    // 日付
    date: nowStr,
    // 温度
    temp:msg.payload.temp,
    // 湿度
    humd:msg.payload.humd,
    // 照度
    light:msg.payload.light
}

return msg;

var now = new Date();

var nowStr =

"" + now.getFullYear() +

"/" + ('0' + (now.getMonth() + 1)).slice(-2) +

"/" + ('0' + now.getDate()).slice(-2) +

" " + ('0' + now.getHours()).slice(-2) +

":" + ('0' + now.getMinutes()).slice(-2) +

":" + ('0' + now.getSeconds()).slice(-2);

msg.payload = {

// 日付

date: nowStr,

// 温度

temp:msg.payload.temp,

// 湿度

humd:msg.payload.humd,

// 照度

light:msg.payload.light

}

return msg;

実行すると、先程同様にCSVデータが出力されます。
出力されたCSVファイルをエクセルで開いてみました。
左から順に、日付、温度、湿度、照度の順で出力されています。

CSVファイル名を動的に変えたい場合は、functionノードを使用しましょう。

以下のように指定します。もちろん、日付をファイル名にすることも可能かと思います。
(fileノードで設定した「ファイル名」は空白にします)

msg.filename = '/home/pi/csv_sample/20180901-test.csv';
return msg;

1 2	msg.filename = '/home/pi/csv_sample/20180901-test.csv'; return msg;

フロー

[{"id":"60e04e8f.e32678","type":"tp-initialize","z":"756369ef.692528","name":"","make":"true","x":140,"y":560,"wires":[]},{"id":"5733eccd.906144","type":"Tibbit-#29","z":"756369ef.692528","name":"","tpSlot":"S02","communication":"I2C","connectedStatus":"start","host":"","x":400,"y":600,"wires":[["e1955500.c25f18"]]},{"id":"1f1ba4b3.2ee613","type":"csv","z":"756369ef.692528","name":"","sep":",","hdrin":"","hdrout":false,"multi":"one","ret":"\\n","temp":"","skip":"0","x":730,"y":740,"wires":[["aa11c4f2.2a9e08"]]},{"id":"aa11c4f2.2a9e08","type":"file","z":"756369ef.692528","name":"","filename":"/home/pi/csv_sample/20180901.csv","appendNewline":false,"createDir":false,"overwriteFile":"false","x":830,"y":800,"wires":[]},{"id":"c626f1ff.b26928","type":"function","z":"756369ef.692528","name":"CSVデータ作成","func":"var now = new Date();\nvar nowStr = \n    \"\" + now.getFullYear() + \n    \"/\" + ('0' + (now.getMonth() + 1)).slice(-2) + \n\t\"/\" + ('0' + now.getDate()).slice(-2) + \n\t\" \" + ('0' + now.getHours()).slice(-2) + \n\t\":\" + ('0' + now.getMinutes()).slice(-2) + \n\t\":\" + ('0' + now.getSeconds()).slice(-2);\n\nmsg.payload = {\n    // 日付\n    date: nowStr,\n    // 温度\n    temp:msg.payload.temp,\n    // 湿度\n    humd:msg.payload.humd,\n    // 照度\n    light:msg.payload.light\n}\n\nreturn msg;\n","outputs":1,"noerr":0,"x":560,"y":740,"wires":[["1f1ba4b3.2ee613"]]},{"id":"317d2221.d7de2e","type":"Tibbit-#28","z":"756369ef.692528","name":"","tpSlot":"S01","communication":"I2C","connectedStatus":"start","host":"","x":400,"y":540,"wires":[["fee1b120.ae6148"]]},{"id":"98fb06e7.3aa1","type":"Tibbit-#30","z":"756369ef.692528","name":"","tpSlot":"S03","communication":"I2C","connectedStatus":"start","host":"","x":400,"y":660,"wires":[["99a21d2d.e863d8"]]},{"id":"53b7f6e4.43011","type":"function","z":"756369ef.692528","name":"センサーデータ取得","func":"var light = context.get(\"ctx_light\")||\"\";\nvar temp = context.get(\"ctx_temp\")||\"\";\nvar humd = context.get(\"ctx_humd\")||\"\";\n\nif(msg.num === 1){\n    light = msg.payload;\n}else if(msg.num === 2){\n    temp = msg.payload;\n}else if(msg.num === 3){\n    humd = msg.payload.humd;\n}\n\nif(light !== \"\" && temp !== \"\" && humd !== \"\"){\n    msg.payload = {\n        temp: temp, \n        light: light, \n        humd: humd\n    };\n    \n    context.set(\"ctx_light\",\"\");\n    context.set(\"ctx_temp\",\"\");\n    context.set(\"ctx_humd\",\"\");\n    return msg;\n    \n}else{\n    \n    context.set(\"ctx_light\", light);\n    context.set(\"ctx_temp\", temp);\n    context.set(\"ctx_humd\", humd);\n    return null;\n    \n}","outputs":1,"noerr":0,"x":820,"y":600,"wires":[["c626f1ff.b26928"]]},{"id":"fee1b120.ae6148","type":"function","z":"756369ef.692528","name":"フラグセット","func":"\nmsg.num = 1;\nreturn msg;","outputs":1,"noerr":0,"x":600,"y":540,"wires":[["53b7f6e4.43011"]]},{"id":"e1955500.c25f18","type":"function","z":"756369ef.692528","name":"フラグセット","func":"\nmsg.num = 2;\nreturn msg;","outputs":1,"noerr":0,"x":600,"y":600,"wires":[["53b7f6e4.43011"]]},{"id":"99a21d2d.e863d8","type":"function","z":"756369ef.692528","name":"フラグセット","func":"\nmsg.num = 3;\nreturn msg;","outputs":1,"noerr":0,"x":600,"y":660,"wires":[["53b7f6e4.43011"]]},{"id":"785818c0.e1a278","type":"inject","z":"756369ef.692528","name":"","topic":"","payload":"","payloadType":"date","repeat":"60","crontab":"","once":false,"onceDelay":0.1,"x":170,"y":620,"wires":[["5733eccd.906144","317d2221.d7de2e","98fb06e7.3aa1"]]}]

[{"id":"60e04e8f.e32678","type":"tp-initialize","z":"756369ef.692528","name":"","make":"true","x":140,"y":560,"wires":[]},{"id":"5733eccd.906144","type":"Tibbit-#29","z":"756369ef.692528","name":"","tpSlot":"S02","communication":"I2C","connectedStatus":"start","host":"","x":400,"y":600,"wires":[["e1955500.c25f18"]]},{"id":"1f1ba4b3.2ee613","type":"csv","z":"756369ef.692528","name":"","sep":",","hdrin":"","hdrout":false,"multi":"one","ret":"\\n","temp":"","skip":"0","x":730,"y":740,"wires":[["aa11c4f2.2a9e08"]]},{"id":"aa11c4f2.2a9e08","type":"file","z":"756369ef.692528","name":"","filename":"/home/pi/csv_sample/20180901.csv","appendNewline":false,"createDir":false,"overwriteFile":"false","x":830,"y":800,"wires":[]},{"id":"c626f1ff.b26928","type":"function","z":"756369ef.692528","name":"CSVデータ作成","func":"var now = new Date();\nvar nowStr = \n \"\" + now.getFullYear() + \n \"/\" + ('0' + (now.getMonth() + 1)).slice(-2) + \n\t\"/\" + ('0' + now.getDate()).slice(-2) + \n\t\" \" + ('0' + now.getHours()).slice(-2) + \n\t\":\" + ('0' + now.getMinutes()).slice(-2) + \n\t\":\" + ('0' + now.getSeconds()).slice(-2);\n\nmsg.payload = {\n // 日付\n date: nowStr,\n // 温度\n temp:msg.payload.temp,\n // 湿度\n humd:msg.payload.humd,\n // 照度\n light:msg.payload.light\n}\n\nreturn msg;\n","outputs":1,"noerr":0,"x":560,"y":740,"wires":[["1f1ba4b3.2ee613"]]},{"id":"317d2221.d7de2e","type":"Tibbit-#28","z":"756369ef.692528","name":"","tpSlot":"S01","communication":"I2C","connectedStatus":"start","host":"","x":400,"y":540,"wires":[["fee1b120.ae6148"]]},{"id":"98fb06e7.3aa1","type":"Tibbit-#30","z":"756369ef.692528","name":"","tpSlot":"S03","communication":"I2C","connectedStatus":"start","host":"","x":400,"y":660,"wires":[["99a21d2d.e863d8"]]},{"id":"53b7f6e4.43011","type":"function","z":"756369ef.692528","name":"センサーデータ取得","func":"var light = context.get(\"ctx_light\")||\"\";\nvar temp = context.get(\"ctx_temp\")||\"\";\nvar humd = context.get(\"ctx_humd\")||\"\";\n\nif(msg.num === 1){\n light = msg.payload;\n}else if(msg.num === 2){\n temp = msg.payload;\n}else if(msg.num === 3){\n humd = msg.payload.humd;\n}\n\nif(light !== \"\" && temp !== \"\" && humd !== \"\"){\n msg.payload = {\n temp: temp, \n light: light, \n humd: humd\n };\n \n context.set(\"ctx_light\",\"\");\n context.set(\"ctx_temp\",\"\");\n context.set(\"ctx_humd\",\"\");\n return msg;\n \n}else{\n \n context.set(\"ctx_light\", light);\n context.set(\"ctx_temp\", temp);\n context.set(\"ctx_humd\", humd);\n return null;\n \n}","outputs":1,"noerr":0,"x":820,"y":600,"wires":[["c626f1ff.b26928"]]},{"id":"fee1b120.ae6148","type":"function","z":"756369ef.692528","name":"フラグセット","func":"\nmsg.num = 1;\nreturn msg;","outputs":1,"noerr":0,"x":600,"y":540,"wires":[["53b7f6e4.43011"]]},{"id":"e1955500.c25f18","type":"function","z":"756369ef.692528","name":"フラグセット","func":"\nmsg.num = 2;\nreturn msg;","outputs":1,"noerr":0,"x":600,"y":600,"wires":[["53b7f6e4.43011"]]},{"id":"99a21d2d.e863d8","type":"function","z":"756369ef.692528","name":"フラグセット","func":"\nmsg.num = 3;\nreturn msg;","outputs":1,"noerr":0,"x":600,"y":660,"wires":[["53b7f6e4.43011"]]},{"id":"785818c0.e1a278","type":"inject","z":"756369ef.692528","name":"","topic":"","payload":"","payloadType":"date","repeat":"60","crontab":"","once":false,"onceDelay":0.1,"x":170,"y":620,"wires":[["5733eccd.906144","317d2221.d7de2e","98fb06e7.3aa1"]]}]

補足

injectノードの繰り返しの設定を行うと定期的に出力することができます。