SHA2017 Badge CO2 Sensor

MicroPython program for reading an MH-Z19 carbon dioxide sensor. The values are displayed on the badge's display as a single stat and graph, pushed to MQTT and used as a trigger for alerts.

Also reads a BME280 climate sensor as a bonus.

The CO2 warning thresholds are set to levels suitable to reduce the risk of Coronavirus infections.

The MQTT topics are listed below, the value is the raw decimal number without unit. The prefix and (room) name can be altered by setting them with the machine.nvs_setstr functions over a serial connection.

• ${mqtt.prefix}/${name}/co2_ppm
• ${mqtt.prefix}/${name}/temperature_c
• ${mqtt.prefix}/${name}/pressure_hpa
• ${mqtt.prefix}/${name}/humidity_pct

NVS settings:

Space	Key	Default
owner	name	<whatever you have set>
sensors	mqtt.server	test.mosquitto.org
sensors	mqtt.prefix	space/climate

Category: hardware

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Status: unknown

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• SHA2017 Badge: unknown

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Download latest egg (tar.gz)

File	Last edited	Size
README.md	2021-01-18 21:48:44	1.04 KiB
__init__.py	2021-01-18 21:48:44	8.58 KiB
bme280_float.py	2021-01-18 21:48:44	9.02 KiB
mhz19.py	2021-01-18 21:48:44	1.54 KiB