Mit Node-Red ist eine schnelle Umsetzung von getriggerten Ereignissen eine Prozedur auszulösen, möglich. In diesem Fall werden alle 30 Minuten lokale Temperatur- und Luftdruckwerte erfasst. Dieser Werte werden dann in Echtzeit auf einen Twitterkanal getwittert https://twitter.com/123iot .
Voraussetzung ist eine Datenquelle mit einem Kleincomputer , wie z.B
https://github.com/unixweb/myweather und einem Raspberry Pi. Dieser liefert mit den abgebildeten Sensoren die nötigen Werte für „Temperatur“ und „Luftdruck“. Die Werte werden via MQTT Protokoll an einen MQTT-Broker gesendet : https://blog.unixweb.de/public-mqtt-server-liste/
Die Programmierung ist sehr einfach gehalten und ist wie folgt für Temperatur.
[{"id":"5dded134.3d1928","type":"debug","z":"948902c9.9fe68","name":"","active":true,"console":"false","complete":"false","x":786.199951171875,"y":145,"wires":[]},{"id":"df167b84.8c6f38","type":"function","z":"948902c9.9fe68","name":"Parse Temperature","func":"var now = Date();\n// JSON Antwort parsen\nvar weather=JSON.parse(msg.payload);\n \n// Neue Nachricht mit Payload erstellen\nvar newMsg = { payload: \"Die aktuelle Temperatur in München ist \"+weather + \" Grad.\\r\" +now};\n \n// Zurückgeben der Nachricht\nreturn [newMsg];","outputs":1,"x":477.199951171875,"y":146,"wires":[["5dded134.3d1928","4dfe29e4.80a488"]]},{"id":"4dfe29e4.80a488","type":"twitter out","z":"948902c9.9fe68","twitter":"","name":"Tweet","x":765,"y":96.79998779296875,"wires":[]},{"id":"40358761.03258","type":"mqtt in","z":"948902c9.9fe68","name":"Temperature","topic":"temp/munich","qos":"2","broker":"3e3899a1.59ea96","x":187.00003051757812,"y":145.79995727539062,"wires":[["df167b84.8c6f38"]]},{"id":"3e3899a1.59ea96","type":"mqtt-broker","z":"","broker":"mqtt.unixweb.de","port":"1883","clientid":"","usetls":false,"compatmode":true,"keepalive":"15","cleansession":true,"willTopic":"","willQos":"0","willPayload":"","birthTopic":"","birthQos":"0","birthPayload":""}]
Text einfach kopieren und in Node-Red in das Clipboard importieren:
[{"id":"a7852095.3505f","type":"debug","z":"948902c9.9fe68","name":"","active":true,"console":"false","complete":"false","x":775.199951171875,"y":243.20001220703125,"wires":[]},{"id":"10a7f9f5.690e3e","type":"function","z":"948902c9.9fe68","name":"Parse Pressure","func":"var now = Date();\n// JSON Antwort parsen\nvar weather=JSON.parse(msg.payload);\n \n// Neue Nachricht mit Payload erstellen\nvar newMsg = { payload: \"Der aktuelle Luftdruck in München ist \"+weather + \" hPa.\\r\" +now};\n \n// Zurückgeben der Nachricht\nreturn [newMsg];","outputs":1,"noerr":0,"x":476.199951171875,"y":241.20001220703125,"wires":[["a7852095.3505f","36d2eda1.2a01aa"]]},{"id":"8aca9b98.2d33f8","type":"mqtt in","z":"948902c9.9fe68","name":"Air Pressure","topic":"press/pX","qos":"2","broker":"3e3899a1.59ea96","x":161,"y":240.99996948242188,"wires":[["10a7f9f5.690e3e"]]},{"id":"36d2eda1.2a01aa","type":"twitter out","z":"948902c9.9fe68","twitter":"","name":"Tweet","x":758,"y":197,"wires":[]},{"id":"3e3899a1.59ea96","type":"mqtt-broker","z":"","broker":"mqtt.unixweb.de","port":"1883","clientid":"","usetls":false,"compatmode":true,"keepalive":"15","cleansession":true,"willTopic":"","willQos":"0","willPayload":"","birthTopic":"","birthQos":"0","birthPayload":""}]
Das Ergebnis sieht dann auf Twitter wie folgt aus:
Viel Spaß beim twittern wünscht , Joachim
