This is an extension for the MagicMirror².

It monitors CO2 level from MH-Z19 sensor and draws a chart for a few last hours.

1. Navigate into your MagicMirror's modules folder

2. Clone repository git clone https://github.com/awitwicki/MMM-MHZ19

3. Go to newly created directory

4. Execute npm install to install the node dependencies.

If you got error, try to execute npm install chartjs

5. Connect the MH-Z19 to your Raspberry Pi

Add it to the modules array in the config/config.js file:

modules: [
	...
	{
		module:  'MMM-MHZ19',
		position:  'top_left',
		config: {
			updateInterval:  100  //seconds
			}
	},
	...
]

Configurations properties

For more details about BCM pin numbers check here

• python3 (should be installed on Raspberry Pi)

• RPi.GPIO (Python library, should be installed on Raspberry Pi )

1. Navigate into your MagicMirror folder
2. Run .sh script ./modules/MMM-MHZ19/mh_z19.sh (If script doesn't run, add exec parameter to it) sudo chmod +x modules/MMM-MHZ19/mh_z19.sh.
3. Script should print sensor values like this 566 - that means CO2 PPM in air

Notice that MH-Z19 module can return small values (<400 PPM) continuously in a few seconds after hardware module was started (by connecting power voltage pin).

MMM-DHT-Sensor module