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Diffstat (limited to 'README.md')
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1 files changed, 30 insertions, 12 deletions
@@ -1,8 +1,9 @@ -# ESP8266 Lua/NodeMCU module for MH-Z19 CO₂ sensor +# ESP8266 Lua/NodeMCU module for MH-Z19 CO₂ sensors -This repository contains a Lua module (`mh-z19.lua`) as well as ESP8266/NodeMCU -MQTT gateway application example (`init.lua`) for the **MH-Z19** carbon dioxide -(CO₂) sensor. +[esp8266-nodemcu-mh-z19](https://finalrewind.org/projects/esp8266-nodemcu-mh-z19/) +provides an ESP8266 NodeMCU Lua module (`mh-z19.lua`) as well as MQTT / +HomeAssistant / InfluxDB gateway application example (`init.lua`) for +**MH-Z19** carbon dioxide (CO₂) sensors connected via UART. ## Dependencies @@ -19,7 +20,6 @@ following modules. * node * softuart * tmr -* uart * wifi ## Setup @@ -27,7 +27,7 @@ following modules. Connect the MH-Z19 sensor to your ESP8266/NodeMCU board as follows. * MH-Z19 GND (black wire) → ESP8266/NodeMCU GND -* MH-Z19 Vin (red wire) → ESP8266/NodeMCU 5V +* MH-Z19 Vin (red wire) → NodeMCU 5V * MH-Z19 Rx (blue wire) → NodeMCU D1 (ESP8266 GPIO5) * MH-Z19 Tx (green wire) → NodeMCU D2 (ESP8266 GPIO4) @@ -47,25 +47,29 @@ port:on("data", 9, uart_callback) function uart_callback(data) if mh_z19.parse_frame(data) then - -- mh_z19.co2 contains the CO₂ concentration in ppm + -- mh_z19.co2 : CO₂ concentration [ppm] + -- mh_z19.temp : device temperature [°c] + -- mh_z19.abc_ticks : ticks since last Automatic Baseline Correction + -- mh_z19.abc_count : number of Automatic Baseline Corrections performed since power-on end end -port:write(mhz19.c_query) +port:write(mh_z19.c_query) ``` +The sensor performs a CO₂ measurement every one to five seconds, depending on hardware revision. + ## Application Example **init.lua** is an example application with HomeAssistant integration. To use it, you need to create a **config.lua** file with WiFI and MQTT settings: ```lua -station_cfg.ssid = "..." -station_cfg.pwd = "..." +station_cfg = {ssid = "...", pwd = "..."} mqtt_host = "..." ``` -Optionally, it can also publish readings to an InfluxDB. +Optionally, it can also publish readings to InfluxDB. To do so, configure URL and attribute: ```lua @@ -73,4 +77,18 @@ influx_url = "..." influx_attr = "..." ``` -Readings will be stored as `mh_z19,[influx_attr] co2_ppm=...` +Readings will be published as `mh_z19[influx_attr] co2_ppm=%d,temperature_celsius=%d,abc_ticks=%d,abc_count=%d`. +So, unless `influx_attr = ''`, it must start with a comma, e.g. `influx_attr = ',device=' .. device_id`. + +## Images + + + + +## Resources + +Mirrors of this repository are maintained at the following locations: + +* [Chaosdorf](https://chaosdorf.de/git/derf/esp8266-nodemcu-mh-z19) +* [git.finalrewind.org](https://git.finalrewind.org/esp8266-nodemcu-mh-z19/) +* [GitHub](https://github.com/derf/esp8266-nodemcu-mh-z19) |