co2monitor/co2Monitor.js

Node for the Dostmann CO2 Monitor mini. If there are permission errors on LIBUSB, you have to add a new file to '/etc/udev/rules.d' with the following record SUBSYSTEM=="usb", MODE="0660", GROUP="plugdev"

module.exports = function(RED) {
	function co2Monitor(config) {

        RED.nodes.createNode(this,config);

		let info = { sensorid: config.sensorid, room: config.room, desc: config.desc };
		
        let node = this;

		let msg = {
			payload : {
				sensorid : info.sensorid,
				room : info.room,
				description : info.desc,
				tempC : null,
				tempF : null,
				co2 : null,
				airQuailty : null,
				humidity : null
			}
		};

		const airCo2ntrol = require('./airCo2ntrol');

		const device = new airCo2ntrol();

		device.connect((err) => {
			if (err) {
				node.error("Error connect HID interface: " + err);
			}
			node.log("device connected");
		
			device.transfer();
		});

		device.on('tempC', (temperature) => {
			if(msg.payload.tempC != temperature) {
				msg.payload.tempC = temperature;
				msg.payload.tempF = parseFloat(((temperature * 1.8) + 32).toFixed(2));
				node.send([null, msg.payload.tempC, msg.payload.tempF, null, msg]);
			}
			node.status({fill:msg.payload.airQuailty,shape:"dot",text: "CO2 = " + msg.payload.co2 + "ppm / Temperature = " + msg.payload.tempC + "°C / " + msg.payload.tempF + "°F"});
		});

		device.on('co2', (co2) => {
			if(msg.payload.co2 != co2) {
				msg.payload.co2 = co2;
				msg.payload.airQuailty = _air_quality(msg.payload.co2);
				node.send([msg.payload.co2, null, null, null, msg]);
			}
			node.status({fill:msg.payload.airQuailty,shape:"dot",text: "CO2 = " + msg.payload.co2 + "ppm / Temperature = " + msg.payload.tempC + "°C / " + msg.payload.tempF + "°F"});
		});

		device.on('hum', (humidity) => {
			if(msg.payload.humidity != humidity) {
				msg.payload.humidity = humidity;
				node.send([null, null, null, msg.payload.humidity, msg]);
			}
		});

	function _air_quality(co2Value) {
		if(co2Value <= 800) {
			return "green";
		}
		else if(co2Value > 800 && co2Value <= 1200) {
			return "yellow";	
		}
		else  {
			return "red";
		}
	}
	}

	RED.nodes.registerType("co2Monitor",co2Monitor);
}