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| -rw-r--r-- | .gitignore | 1 | ||||
| -rw-r--r-- | README.md | 55 | ||||
| -rw-r--r-- | init.lua | 75 | ||||
| -rw-r--r-- | pm1006.lua | 20 |
4 files changed, 151 insertions, 0 deletions
diff --git a/.gitignore b/.gitignore new file mode 100644 index 0000000..338c30b --- /dev/null +++ b/.gitignore @@ -0,0 +1 @@ +config.lua diff --git a/README.md b/README.md new file mode 100644 index 0000000..e592ccb --- /dev/null +++ b/README.md @@ -0,0 +1,55 @@ +# ESP8266 Lua/NodeMCU module for Vindriktning PM1006 particle monitor + +This repository contains a Lua module (`pm1006.lua`) as well as ESP8266/NodeMCU +MQTT gateway application example (`init.lua`) for the **PM1006** particulate +matter (PM2.5) sensor found in IKEA Vindriktning. + +## Dependencies + +pm1006.lua has been tested with Lua 5.1 on NodeMCU firmware 3.0.1 (Release +202112300746, integer build). Most practical applications (such as the example +in init.lua) require the following modules. + +* gpio +* mqtt +* node +* softuart +* tmr +* uart +* wifi + +## Setup + +Connect the PM1006 sensor to your ESP8266/NodeMCU board as [documented by Hypfer](https://github.com/Hypfer/esp8266-vindriktning-particle-sensor). + +If you use a different UART pin, you need to adjust the softuart.setup call in +the examples provided in this repository to reflect that change. Keep in mind +that some ESP8266 pins must have well-defined logic levels at boot time and may +therefore be unsuitable for PM1006 connection. + +## Usage + +Copy **pm1006.lua** to your NodeMCU board and set it up as follows. + +```lua +pm1006 = require("pm1006") +port = softuart.setup(9600, nil, 2) +port:on("data", 20, uart_callback) + +function uart_callback(data) + local pm2_5 = pm1006.parse_frame(data) + if pm25i ~= nil then + -- pm2_5 contains PM2.5 value in µg/m³ + else + -- invalid frame header or checksum + end +end +``` + +See **init.lua** for an example. To use it, you need to create a **config.lua** file with WiFI and MQTT settings: + +```lua +station_cfg.ssid = "..." +station_cfg.pwd = "..." +mqtt_host = "..." +``` diff --git a/init.lua b/init.lua new file mode 100644 index 0000000..fe53b86 --- /dev/null +++ b/init.lua @@ -0,0 +1,75 @@ +station_cfg = {} +dofile("config.lua") + +delayed_restart = tmr.create() +chipid = node.chipid() +mqtt_prefix = "sensor/esp8266_" .. chipid +mqttclient = mqtt.Client("esp8266_" .. chipid, 120) + +print("ESP8266 " .. chipid) + +ledpin = 4 +gpio.mode(ledpin, gpio.OUTPUT) +gpio.write(ledpin, 0) + +pm1006 = require("pm1006") + +function log_restart() + print("Network error " .. wifi.sta.status() .. ". Restarting in 20 seconds.") + delayed_restart:start() +end + +function setup_client() + print("Connected") + gpio.write(ledpin, 1) + publishing = true + mqttclient:publish(mqtt_prefix .. "/state", "online", 0, 1, function(client) + publishing = false + end) + port = softuart.setup(9600, nil, 2) + port:on("data", 20, uart_callback) +end + +function connect_mqtt() + print("IP address: " .. wifi.sta.getip()) + print("Connecting to MQTT " .. mqtt_host) + delayed_restart:stop() + mqttclient:on("connect", setup_client) + mqttclient:on("offline", log_restart) + mqttclient:lwt(mqtt_prefix .. "/state", "offline", 0, 1) + mqttclient:connect(mqtt_host) +end + +function connect_wifi() + print("WiFi MAC: " .. wifi.sta.getmac()) + print("Connecting to ESSID " .. station_cfg.ssid) + wifi.eventmon.register(wifi.eventmon.STA_GOT_IP, connect_mqtt) + wifi.eventmon.register(wifi.eventmon.STA_DHCP_TIMEOUT, log_restart) + wifi.eventmon.register(wifi.eventmon.STA_DISCONNECTED, log_restart) + wifi.setmode(wifi.STATION) + wifi.sta.config(station_cfg) + wifi.sta.connect() +end + +function uart_callback(data) + local pm2_5 = pm1006.parse_frame(data) + if pm2_5 == nil then + print("Invalid PM1006 frame") + return + else + local json_str = string.format('{"pm25_ugm3": %d, "rssi_dbm": %d}', pm2_5, wifi.sta.getrssi()) + if not publishing then + publishing = true + gpio.write(ledpin, 0) + mqttclient:publish(mqtt_prefix .. "/data", json_str, 0, 0, function(client) + publishing = false + gpio.write(ledpin, 1) + collectgarbage() + end) + end + end +end + +delayed_restart:register(20 * 1000, tmr.ALARM_SINGLE, node.restart) + +connect_wifi() diff --git a/pm1006.lua b/pm1006.lua new file mode 100644 index 0000000..1aeed17 --- /dev/null +++ b/pm1006.lua @@ -0,0 +1,20 @@ +local pm1006 = {} + +function pm1006.parse_frame(data) + if string.byte(data, 1) ~= 0x16 or string.byte(data, 2) ~= 0x11 or string.byte(data, 3) ~= 0x0b then + -- invalid header + return nil + end + local checksum = 0 + for i = 1, 20 do + checksum = (checksum + string.byte(data, i)) % 256 + end + if checksum ~= 0 then + -- invalid checksum + return nil + end + local pm2_5 = string.byte(data, 6) * 256 + string.byte(data, 7) + return pm2_5 +end + +return pm1006 |