Carbon Dioxide Sensor
Updated October 15, 2021 by djiwondee, crxporter, caitken-com and ShaquuUUID: 00000097-0000-1000-8000-0026BB765291
Characteristics
| Name | Required |
|---|---|
| CarbonDioxideLevel | ✕ |
| CarbonDioxidePeakLevel | ✕ |
| Name | ✕ |
| StatusActive | ✕ |
| StatusFault | ✕ |
| StatusLowBattery | ✕ |
| StatusTampered | ✕ |
| CarbonDioxideDetected | ✓ |
Example
These examples are meant to be copied into your Node-RED system and adapted to your setup.
Please note: Different from other HomeKit services (e.g. temperature sensor) the Home.app is not showing the carbon dioxide level on the device icon. To view the current value you have to open the preferences of the device in the Home.app. This works as designed by Apple and can’t be changed with characteristics properties.
Simple CO2 Sensor
This example is a simple CO2 sensor that is only ever “triggered” or “normal”.
The msg.payload going in is either {"CarbonDioxideDetected":1} or {"CarbonDioxideDetected":0} where 1 is “carbon dioxide detected” and 0 is “normal conditions”.
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Full Featured CO2 Sensor
This is an example of a CO2 Sensor that triggers an event message in the Home.app in case the CO2 level is above a threshold level of 1000. In this example the input nodes is an inject node just for a value of an assumed carbon dioxide level. In real life the author of that example gather the current value from a Netatmo weather stations by accessing the Netatmo Connect API. The debug node will return values set in the payload as it available in the Home.app on an Apple device.
Copyable Node-RED flow:
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This example triggers a message in iOS if the carbon dioxide level raises above 1000 ppm a set the status of the device in the Home.app to peak level detected. You can now use that to create an automation in the Home.app triggered by carbon dioxide peak level. If the level would fall below the selected peak level, the Peak level detection will be deactivated. In addition to that you can now ask Siri what the carbon dioxide level in the room you assign the sensor in the Home.app. But most important, if you are using Netatmo Weather Station as the source of your in and outdoor climatic measurement you can now bridge the gap of the missing HomeKit compatibility of Netatmo.
Monitoring peak level and event handling
This is another example how to deal with the event interaction on iOS. The following flow saves the recent peak level in a context variable of the node and always updates the CarbonDioxidePeakLevel if it is larger than the previous measurement cycle.
If the level goes up a particular value (e.g. 1000ppm is set in the example) it changes the CarbonDioxideDetected property to 1 which causes an alarm in the iOS Home.app.
The alarm will be reset after 30sec based on the individual reset. Also, the recent peak level is set to null for some reasons.
Copyable Node-RED flow:
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Some credits for this example goes to crxporter for the inspiration.
Full CO2 Example from Demo
This is a copy of the Demo CO2 sensor. It has inject nodes for random “safe”, random “unsafe”, and a reset to 0 level. Additionally it has active | inactive | NO_RESPONSE handling.
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Options are:\n\n**0 ppm:** this will assume no CO2 <br/>\n**Safe level:** this will assume a level between 1 and 999 ppm, inclusive <br/>\n**Dangerous level:** this will assume a level between 1,000 and 100,000, inclusive; this will also trigger an alert"},{"id":"88892b4.8a61bd8","type":"homekit-service","z":"58d0ac22b8a060e3","g":"ab48426e.25466","isParent":true,"hostType":"0","bridge":"409001a1.3e7a78","accessoryId":"","parentService":"","name":"CO2 Sensor","serviceName":"CarbonDioxideSensor","topic":"","filter":false,"manufacturer":"Default Manufacturer","model":"Carbon","serialNo":"Default Serial Number","firmwareRev":"22","hardwareRev":"11","softwareRev":"","cameraConfigVideoProcessor":"","cameraConfigSource":"","cameraConfigStillImageSource":"","cameraConfigMaxStreams":"","cameraConfigMaxWidth":"","cameraConfigMaxHeight":"","cameraConfigMaxFPS":"","cameraConfigMaxBitrate":"","cameraConfigVideoCodec":"","cameraConfigAudioCodec":"","cameraConfigAudio":false,"cameraConfigPacketSize":"","cameraConfigVerticalFlip":false,"cameraConfigHorizontalFlip":false,"cameraConfigMapVideo":"","cameraConfigMapAudio":"","cameraConfigVideoFilter":"","cameraConfigAdditionalCommandLine":"","cameraConfigDebug":false,"cameraConfigSnapshotOutput":"disabled","cameraConfigInterfaceName":"","characteristicProperties":"{ \"CarbonDioxideLevel\" : true, \"CarbonDioxidePeakLevel\": true, \"StatusActive\" : true}","waitForSetupMsg":false,"outputs":2,"x":790,"y":860,"wires":[[],[]]},{"id":"3611c654.8a42f2","type":"function","z":"58d0ac22b8a060e3","g":"ab48426e.25466","name":"Random values, peak value","func":"// Reset all values to 0 if 0ppm input\nif(msg.payload === 0){\n context.set('lastPeak',0);\n newMsg = {\n payload: {\n \"CarbonDioxideLevel\":0,\n \"CarbonDioxidePeakLevel\":0,\n \"CarbonDioxideDetected\":0\n }\n };\n return newMsg;\n}\n\n// Initialize vars\nvar CurrentLevel = 0;\nvar lastPeak = context.get('lastPeak');\n\n// Set random safe or dangerous levels\nif(msg.payload === \"Safe\"){\n CurrentLevel = Math.floor(Math.random() * (999 - 1 + 1) + 1);\n}\nif(msg.payload === \"Danger\"){\n CurrentLevel = Math.floor(Math.random() * (100000 - 1000 + 1) + 1000);\n}\n\n// Formulate output message\nvar newMsg = {\n payload: {\n \"CarbonDioxideLevel\" : CurrentLevel,\n \"CarbonDioxideDetected\" : 0\n }\n};\n\n// Set new peak level\nif(CurrentLevel > lastPeak){\n lastPeak = CurrentLevel;\n context.set('lastPeak',CurrentLevel);\n newMsg.payload.CarbonDioxidePeakLevel = CurrentLevel;\n}\n\n// Set warning if dangerous\nif (CurrentLevel >= 1000) {\n newMsg.payload.CarbonDioxideDetected = 1;\n} \n\nreturn newMsg;","outputs":1,"noerr":0,"initialize":"// Code added here will be run once\n// whenever the node is deployed.\ncontext.set('lastPeak',0);\n","finalize":"","x":520,"y":860,"wires":[["88892b4.8a61bd8"]]},{"id":"62cafcb0.8ade9c","type":"inject","z":"58d0ac22b8a060e3","g":"ab48426e.25466","name":"Active","repeat":"","crontab":"","once":false,"onceDelay":0.1,"topic":"","payload":"{\"StatusActive\":true}","payloadType":"json","x":590,"y":900,"wires":[["88892b4.8a61bd8"]]},{"id":"a0171cdb.f209b","type":"inject","z":"58d0ac22b8a060e3","g":"ab48426e.25466","name":"Inactive","repeat":"","crontab":"","once":false,"onceDelay":0.1,"topic":"","payload":"{\"StatusActive\":false}","payloadType":"json","x":590,"y":940,"wires":[["88892b4.8a61bd8"]]},{"id":"6f7de764.a6a688","type":"inject","z":"58d0ac22b8a060e3","g":"ab48426e.25466","name":"NO RESPONSE","repeat":"","crontab":"","once":false,"onceDelay":0.1,"topic":"","payload":"{\"CarbonDioxideLevel\":\"NO_RESPONSE\"}","payloadType":"json","x":560,"y":980,"wires":[["88892b4.8a61bd8"]]},{"id":"8758b463.afb0f","type":"inject","z":"58d0ac22b8a060e3","g":"ab48426e.25466","name":"0 ppm","props":[{"p":"payload"}],"repeat":"","crontab":"","once":false,"onceDelay":0.1,"topic":"","payload":"0","payloadType":"num","x":230,"y":860,"wires":[["3611c654.8a42f2"]]},{"id":"69e8161b.74b7a","type":"inject","z":"58d0ac22b8a060e3","g":"ab48426e.25466","name":"Safe Level","props":[{"p":"payload"}],"repeat":"","crontab":"","once":false,"onceDelay":0.1,"topic":"","payload":"Safe","payloadType":"str","x":240,"y":900,"wires":[["3611c654.8a42f2"]]},{"id":"40010b09.c73cdc","type":"inject","z":"58d0ac22b8a060e3","g":"ab48426e.25466","name":"Dangerous level","props":[{"p":"payload"}],"repeat":"","crontab":"","once":false,"onceDelay":0.1,"topic":"","payload":"Danger","payloadType":"str","x":260,"y":940,"wires":[["3611c654.8a42f2"]]},{"id":"409001a1.3e7a78","type":"homekit-bridge","bridgeName":"Demo 1","pinCode":"153-10-538","port":"","allowInsecureRequest":false,"manufacturer":"NRCHKB","model":"Demo","serialNo":"1.1.2","customMdnsConfig":false,"mdnsMulticast":true,"mdnsInterface":"","mdnsPort":"","mdnsIp":"","mdnsTtl":"","mdnsLoopback":true,"mdnsReuseAddr":true,"allowMessagePassthrough":true}]