add esp8266 vindriktning/pm1006

-- 100 mA @ 5V

station_cfg = {}

dofile("wifi.lua")

mqtt_host = "mqtt.chaosdorf.space"

delayed_restart = tmr.create()

chip_id = node.chipid()

device_id = "esp8266_" .. chip_id

mqtt_prefix = "sensor/" .. device_id

mqttclient = mqtt.Client(device_id, 120)

print("ESP8266 " .. chip_id)

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 30 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", hass_register)

	mqttclient:on("connfail", log_restart)

	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

function hass_register()

	local hass_device = string.format('{"connections":[["mac","%s"]],"identifiers":["%s"],"model":"ESP8266","name":"ESP8266 PM1006","manufacturer":"DIY"}', wifi.sta.getmac(), device_id)

	local hass_entity_base = string.format('"device":%s,"state_topic":"%s/data","expire_after":600', hass_device, mqtt_prefix)

	local hass_pm2_5 = string.format('{%s,"name":"PM2.5","object_id":"%s_pm2_5","unique_id":"%s_pm2_5","icon":"mdi:air-filter","unit_of_measurement":"µg/m³","value_template":"{{value_json.pm2_5_ugm3}}"}', hass_entity_base, device_id, device_id)

	local hass_rssi = string.format('{%s,"name":"RSSI","object_id":"%s_rssi","unique_id":"%s_rssi","icon":"mdi:wifi","unit_of_measurement":"dBm","value_template":"{{value_json.rssi_dbm}}","entity_category":"diagnostic"}', hass_entity_base, device_id, device_id)

	mqttclient:publish("homeassistant/sensor/" .. device_id .. "/pm2_5/config", hass_pm2_5, 0, 1, function(client)

		mqttclient:publish("homeassistant/sensor/" .. device_id .. "/rssi/config", hass_rssi, 0, 1, function(client)

			collectgarbage()

			setup_client()

		end)

	end)

end

delayed_restart:register(30 * 1000, tmr.ALARM_SINGLE, node.restart)

delayed_restart:start()

connect_wifi()

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