From 87d61960d7c15084aebffe28b1dea87dc7b716c8 Mon Sep 17 00:00:00 2001
From: Daniel Friesel <derf@finalrewind.org>
Date: Wed, 20 Apr 2022 19:11:35 +0200
Subject: initial commit

---
 init.lua | 102 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 102 insertions(+)
 create mode 100644 init.lua

(limited to 'init.lua')

diff --git a/init.lua b/init.lua
new file mode 100644
index 0000000..8904f95
--- /dev/null
+++ b/init.lua
@@ -0,0 +1,102 @@
+station_cfg = {}
+dofile("config.lua")
+
+delayed_restart = tmr.create()
+push_timer = 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)
+
+scd4x = require("scd4x")
+i2c.setup(0, 2, 1, i2c.SLOW)
+
+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)
+	if not scd4x.start() then
+		print("SCD4x initialization error")
+	end
+	publishing = true
+	mqttclient:publish(mqtt_prefix .. "/state", "online", 0, 1, function(client)
+		publishing = false
+		push_data()
+	end)
+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("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 push_data()
+	local co2, raw_temp, raw_humi = scd4x.read()
+	if co2 == nil then
+		print("SCD4x error")
+	else
+		local json_str = string.format('{"co2_ppm": %d, "temperature_degc": %d.%d, "humidity_relpercent": %d.%d, "rssi_dbm": %d}', co2, raw_temp/65536 - 45, (raw_temp%65536)/6554, raw_humi/65536, (raw_humi%65536)/6554, 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
+	push_timer:start()
+end
+
+function hass_register()
+	local hass_device = string.format('{"connections":[["mac","%s"]],"identifiers":["%s"],"model":"ESP8266","name":"ESP8266 with SCD4x","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_co2 = string.format('{%s,"name":"CO₂","object_id":"%s_co2","unique_id":"%s_co2","device_class":"carbon_dioxide","unit_of_measurement":"ppm","value_template":"{{value_json.co2_ppm}}"}', hass_entity_base, device_id, device_id)
+	local hass_temp = string.format('{%s,"name":"Temperature","object_id":"%s_temperature","unique_id":"%s_temperature","device_class":"temperature","unit_of_measurement":"°c","value_template":"{{value_json.temperature_degc}}"}', hass_entity_base, device_id, device_id)
+	local hass_humi = string.format('{%s,"name":"Humidity","object_id":"%s_humidity","unique_id":"%s_humidity","device_class":"humidity","unit_of_measurement":"%%","value_template":"{{value_json.humidity_relpercent}}"}', hass_entity_base, device_id, device_id)
+	local hass_rssi = string.format('{%s,"name":"RSSI","object_id":"%s_rssi","unique_id":"%s_rssi","device_class":"signal_strength","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 .. "/co2/config", hass_co2, 0, 1, function(client)
+		mqttclient:publish("homeassistant/sensor/" .. device_id .. "/temperature/config", hass_temp, 0, 1, function(client)
+			mqttclient:publish("homeassistant/sensor/" .. device_id .. "/humidity/config", hass_humi, 0, 1, function(client)
+				mqttclient:publish("homeassistant/sensor/" .. device_id .. "/rssi/config", hass_rssi, 0, 1, function(client)
+					collectgarbage()
+					setup_client()
+				end)
+			end)
+		end)
+	end)
+end
+
+delayed_restart:register(20 * 1000, tmr.ALARM_SINGLE, node.restart)
+push_timer:register(20 * 1000, tmr.ALARM_SEMI, push_data)
+
+connect_wifi()
-- 
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