異なる範囲の数値をマッピングする
課題
ある範囲の数値をスケールさせたい。 たとえば、センサー値が0〜1023の範囲で取得できるものに対して、電圧として0〜5にマッピングするなど。
解決
Range ノードを使用して、定義した範囲にマッピングします。
例
[{"id":"80dae67d.b4d8f8","type":"inject","z":"535331d8.55c1f","name":"","topic":"","payload":"0","payloadType":"num","repeat":"","crontab":"","once":false,"x":130,"y":380,"wires":[["81f13534.456348"]]},{"id":"81f13534.456348","type":"range","z":"535331d8.55c1f","minin":"0","maxin":"1023","minout":"0","maxout":"5","action":"clamp","round":false,"name":"","x":350,"y":420,"wires":[["e80b61d7.4b399"]]},{"id":"cb21de23.75a2f","type":"inject","z":"535331d8.55c1f","name":"","topic":"","payload":"512","payloadType":"num","repeat":"","crontab":"","once":false,"x":130,"y":420,"wires":[["81f13534.456348"]]},{"id":"342552de.255a1e","type":"inject","z":"535331d8.55c1f","name":"","topic":"","payload":"1023","payloadType":"num","repeat":"","crontab":"","once":false,"x":130,"y":460,"wires":[["81f13534.456348"]]},{"id":"e80b61d7.4b399","type":"debug","z":"535331d8.55c1f","name":"","active":true,"console":"false","complete":"false","x":550,"y":420,"wires":[]}]
議論
Range ノードは指定した2つの値の範囲内を直線的にスケールさせるために使用します。
デフォルトでは、結果はノードで定義された範囲に制限されません。 上記の電圧の例でいうと、2046は10にマッピングされます。
このノードはターゲットとする値の範囲を設定することもできますし、 シンプルな合同算術を適用して範囲におさめることもできます。
