Hi there,
I’m sharing a simple app to monitor the level of CO2 in the office during the day using mangOH Yellow and Octave. Feel free to try it and comment below!
Prerequisites
Before starting, make sure you already followed the getting started with mangOH Yellow and Octave: https://mangoh.io/mangoh-yellow-resources-getting-started
Octave concepts used
In this application, I’m using the following Octave components:
- 2 Resources (cf. Octave documentation: https://docs.octave.dev/references/edge/concepts/resources/)
-
environment(air quality) -
imu/temp(temperature)
-
- 3 Observations (cf. Octave documentation: https://docs.octave.dev/references/edge/concepts/observations/)
-
temp_calibration(copy to another resource): initializes the ambientAirTemp value in the environment sensor from the temperature sensor -
environment(send to an Edge action): send toCO2 Alarmedge action -
co_2(send to Cloud): send CO2 value to cloud when the value is above a threashold
-
- 1 Edge Action (cf. Octave documentation: https://docs.octave.dev/references/edge/concepts/edge_actions/)
-
CO2 Alarm: switch on LEDs and buzzer depending on CO2 level in the room
-
Implementation
1. Resources
Enable the 2 resources:
-
environment/ambientAirTemp: put a first value here, like 20 (in °C). -
environment/enable: true -
imu/temp/enable: true -
imu/temp/period: 60 (we’ll be reading this value no more than once a minute)
2. Observations
3. Edge Action
function(event) {
// Check the CO2 in ambient air (measured in ppm)
// Threshold values are based on ANSES recommendations (https://www.anses.fr/fr/system/files/AIR2012sa0093Ra.pdf)
//
// LED is turned respectively:
// green: ideal conditions: CO2 < 600ppm
// blue : OK conditions: CO2 < 1000ppm
// red : warning: CO2 > 1000ppm
// The buzzer is turned respectively:
// ON : critical: CO2 > 1300ppm
// OFF : not critical: CO2 < 1300ppm
var critical = event.value.co2EquivalentValue >= 1300;
var warning = event.value.co2EquivalentValue >= 1000;
var ideal = event.value.co2EquivalentValue < 600;
return {
"dh://leds/tri/green/enable": [ideal],
"dh://leds/tri/blue/enable": [!ideal && !warning],
"dh://leds/tri/red/enable": [warning],
"dh://buzzer/enable": [critical],
"dh://buzzer/percent": [critical ? 20 : 3],
"dh://buzzer/period": [critical ? 2 : 10]
}
}
4. Device stream
Now you may receive events if co2 value is more than 1000 thanks to the observation created before.
Does this simple app run well for you? Let me know in the comments! Enhancement proposals are welcome too!