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diff --git a/.gitignore b/.gitignore
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+config.lua
diff --git a/.reuse/dep5 b/.reuse/dep5
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+++ b/.reuse/dep5
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+Format: https://www.debian.org/doc/packaging-manuals/copyright-format/1.0/
+
+Files: init.lua max44006.lua
+Copyright: 2024 Birte Kristina Friesel
+License: BSD-2-Clause
+
+Files: README.md .gitignore
+Copyright: 2024 Birte Kristina Friesel
+License: CC0-1.0
diff --git a/LICENSES/BSD-2-Clause.txt b/LICENSES/BSD-2-Clause.txt
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+++ b/LICENSES/BSD-2-Clause.txt
@@ -0,0 +1,9 @@
+Copyright (c) <year> <owner> 
+
+Redistribution and use in source and binary forms, with or without modification, are permitted provided that the following conditions are met:
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+1. Redistributions of source code must retain the above copyright notice, this list of conditions and the following disclaimer.
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+
+THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
diff --git a/LICENSES/CC0-1.0.txt b/LICENSES/CC0-1.0.txt
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--- /dev/null
+++ b/LICENSES/CC0-1.0.txt
@@ -0,0 +1,121 @@
+Creative Commons Legal Code
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diff --git a/README.md b/README.md
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+# ESP8266 Lua/NodeMCU module for MAX44006 illuminance sensors
+
+This repository contains an ESP8266 NodeMCU Lua module (`max44006.lua`) as well
+as MQTT / HomeAssistant / InfluxDB integration example (`init.lua`) for
+**MAX44006** irradiance sensors connected via I²C.
+
+## Dependencies
+
+max44006.lua has been tested with Lua 5.1 on NodeMCU firmware 3.0.1 (Release
+202112300746, float build). It requires the following modules.
+
+* bit
+* i2c
+
+Most practical applications (such as the example in init.lua) also need the
+following modules.
+
+* gpio
+* mqtt
+* node
+* tmr
+* wifi
+
+## Setup
+
+Connect the MAX44006 sensor to your ESP8266/NodeMCU board as follows.
+
+* MAX44006 GND → ESP8266/NodeMCU GND
+* MAX44006 VCC → ESP8266/NodeMCU 3V3
+* MAX44006 SDA → NodeMCU D1 (ESP8266 GPIO5)
+* MAX44006 SCL → NodeMCU D2 (ESP8266 GPIO4)
+
+If you use different pins for SCL and SDA, you need to adjust the i2c.setup
+call in the examples provided in this repository to reflect those changes. Keep
+in mind that some ESP8266 pins must have well-defined logic levels at boot time
+and may therefore be unsuitable for MAX44006 connection.
+
+## Usage
+
+Copy **max44006.lua** to your NodeMCU board and set it up as follows.
+
+```lua
+max44006 = require("max44006")
+i2c.setup(0, 1, 2, i2c.SLOW)
+max44006.start()
+
+-- can be called with up to 10 Hz
+function some_timer_callback()
+	if max44006.read() then
+		-- All values are float
+		-- Maximum value is for 1677 blue and 8388 for others
+		-- max44006.red   : Irradiance on Red channel [µW/cm²]
+		-- max44006.green : Irradiance on Green channel [µW/cm²]
+		-- max44006.blue  : Irradiance on Blue channel [µW/cm²]
+		-- max44006.clear : Irradiance on Clear channel [µW/cm²]
+		-- max44006.ir    : Irradiance on IR channel [µW/cm²]
+	else
+		print("MAX44006 error")
+	end
+end
+```
+
+## 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 = "...", pwd = "..."}
+mqtt_host = "..."
+```
+
+Optionally, it can also publish readings to InfluxDB.
+To do so, configure URL and attribute:
+
+```lua
+influx_url = "..."
+influx_attr = "..."
+```
+
+Readings will be published as `max44006[influx_attr] red_uwcm2=%f,green_uwcm2=%f,blue_uwcm2=%f,clear_uwcm2=%f,ir_uwcm2=%f`.
+So, unless `influx_attr = ''`, it must start with a comma, e.g. `influx_attr = ',device=' .. device_id`.
+
+## Images
+
+![](https://finalrewind.org/projects/esp8266-nodemcu-max44006/media/hass.png)
diff --git a/init.lua b/init.lua
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+publishing_mqtt = false
+publishing_http = false
+
+watchdog = tmr.create()
+push_timer = tmr.create()
+chip_id = string.format("%06X", node.chipid())
+device_id = "esp8266_" .. chip_id
+mqtt_prefix = "sensor/" .. device_id
+mqttclient = mqtt.Client(device_id, 120)
+
+dofile("config.lua")
+
+print("MAX44006 " .. chip_id)
+
+ledpin = 4
+gpio.mode(ledpin, gpio.OUTPUT)
+gpio.write(ledpin, 0)
+
+max44006 = require("max44006")
+i2c.setup(0, 1, 2, i2c.SLOW)
+
+function log_restart()
+	print("Network error " .. wifi.sta.status())
+end
+
+function setup_client()
+	print("Connected")
+	gpio.write(ledpin, 1)
+	max44006.start()
+	publishing_mqtt = true
+	mqttclient:publish(mqtt_prefix .. "/state", "online", 0, 1, function(client)
+		publishing_mqtt = false
+		push_timer:start()
+	end)
+end
+
+function connect_mqtt()
+	print("IP address: " .. wifi.sta.getip())
+	print("Connecting to MQTT " .. mqtt_host)
+	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()
+	if max44006.read() then
+		local json_str = string.format('{"red_uwcm2": %f, "green_uwcm2": %f, "blue_uwcm2": %f, "clear_uwcm2": %f, "ir_uwcm2": %f, "rssi_dbm": %d}', max44006.red, max44006.green, max44006.blue, max44006.clear, max44006.ir, wifi.sta.getrssi())
+		local influx_str = string.format("red_uwcm2=%f,green_uwcm2=%f,blue_uwcm2=%f,clear_uwcm2=%f,ir_uwcm2=%f", max44006.red, max44006.green, max44006.blue, max44006.clear, max44006.ir)
+		if not publishing_mqtt then
+			publishing_mqtt = true
+			watchdog:start(true)
+			gpio.write(ledpin, 0)
+			mqttclient:publish(mqtt_prefix .. "/data", json_str, 0, 0, function(client)
+				publishing_mqtt = false
+				if influx_url and influx_attr and influx_str then
+					publish_influx(influx_str)
+				else
+					gpio.write(ledpin, 1)
+					collectgarbage()
+				end
+			end)
+		end
+	else
+		print("MAX44006 error")
+	end
+end
+
+function publish_influx(payload)
+	if not publishing_http then
+		publishing_http = true
+		http.post(influx_url, influx_header, "max44006" .. influx_attr .. " " .. payload, function(code, data)
+			publishing_http = false
+			gpio.write(ledpin, 1)
+			collectgarbage()
+		end)
+	end
+end
+
+function hass_register()
+	local hass_device = string.format('{"connections":[["mac","%s"]],"identifiers":["%s"],"model":"ESP8266 + MAX44006","name":"MAX44006 %s","manufacturer":"derf"}', wifi.sta.getmac(), device_id, chip_id)
+	local hass_entity_base = string.format('"device":%s,"state_topic":"%s/data","expire_after":600', hass_device, mqtt_prefix)
+	local hass_red = string.format('{%s,"name":"Red","object_id":"%s_red","unique_id":"%s_red","device_class":"irradiance","unit_of_measurement":"µW/cm²","value_template":"{{value_json.red_uwcm2}}"}', hass_entity_base, device_id, device_id)
+	local hass_green = string.format('{%s,"name":"Green","object_id":"%s_green","unique_id":"%s_green","device_class":"irradiance","unit_of_measurement":"µW/cm²","value_template":"{{value_json.green_uwcm2}}"}', hass_entity_base, device_id, device_id)
+	local hass_blue = string.format('{%s,"name":"Blue","object_id":"%s_blue","unique_id":"%s_blue","device_class":"irradiance","unit_of_measurement":"µW/cm²","value_template":"{{value_json.blue_uwcm2}}"}', hass_entity_base, device_id, device_id)
+	local hass_clear = string.format('{%s,"name":"Clear","object_id":"%s_clear","unique_id":"%s_clear","device_class":"irradiance","unit_of_measurement":"µW/cm²","value_template":"{{value_json.clear_uwcm2}}"}', hass_entity_base, device_id, device_id)
+	local hass_ir = string.format('{%s,"name":"IR","object_id":"%s_ir","unique_id":"%s_ir","device_class":"irradiance","unit_of_measurement":"µW/cm²","value_template":"{{value_json.ir_uwcm2}}"}', 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 .. "/irradiance_red/config", hass_red, 0, 1, function(client)
+		mqttclient:publish("homeassistant/sensor/" .. device_id .. "/irradiance_green/config", hass_green, 0, 1, function(client)
+			mqttclient:publish("homeassistant/sensor/" .. device_id .. "/irradiance_blue/config", hass_blue, 0, 1, function(client)
+				mqttclient:publish("homeassistant/sensor/" .. device_id .. "/irradiance_clear/config", hass_clear, 0, 1, function(client)
+					mqttclient:publish("homeassistant/sensor/" .. device_id .. "/irradiance_ir/config", hass_ir, 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)
+	end)
+end
+
+watchdog:register(180 * 1000, tmr.ALARM_SEMI, node.restart)
+push_timer:register(20 * 1000, tmr.ALARM_AUTO, push_data)
+watchdog:start()
+
+connect_wifi()
diff --git a/max44006.lua b/max44006.lua
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--- /dev/null
+++ b/max44006.lua
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+local max44006 = {}
+local device_address = 0x45
+
+max44006.bus_id = 0
+
+function max44006.writeReg(reg, data)
+	ret = true
+	i2c.start(max44006.bus_id)
+	if not i2c.address(max44006.bus_id, device_address, i2c.TRANSMITTER) then
+		ret = false
+	end
+	i2c.write(max44006.bus_id, reg, data)
+	i2c.stop(max44006.bus_id)
+	return ret
+end
+
+function max44006.readReg(reg, len)
+	ret = true
+	i2c.start(max44006.bus_id)
+	if not i2c.address(max44006.bus_id, device_address, i2c.TRANSMITTER) then
+		ret = false
+	end
+	i2c.write(max44006.bus_id, reg)
+	i2c.start(max44006.bus_id)
+	if not i2c.address(max44006.bus_id, device_address, i2c.RECEIVER) then
+		ret = false
+	end
+	local data = i2c.read(max44006.bus_id, len)
+	i2c.stop(max44006.bus_id)
+	return ret, data
+end
+
+function max44006.start()
+	max44006.readReg(0x00, 1)
+	max44006.readReg(0x00, 1)
+	max44006.writeReg(0x01, 0x20)
+	max44006.writeReg(0x02, 0x03)
+end
+
+function max44006.read()
+	ret = true
+	i2c.start(max44006.bus_id)
+	if not i2c.address(max44006.bus_id, device_address, i2c.TRANSMITTER) then
+		ret = false
+	end
+	i2c.write(max44006.bus_id, {0x04})
+	--i2c.stop(max44006.bus_id)
+	i2c.start(max44006.bus_id)
+	if not i2c.address(max44006.bus_id, device_address, i2c.RECEIVER) then
+		ret = false
+	end
+	local data = i2c.read(max44006.bus_id, 10)
+	i2c.stop(max44006.bus_id)
+
+	local mul = 0.512
+	max44006.clear = (bit.lshift(string.byte(data, 1), 8) + string.byte(data, 2)) * mul
+	max44006.red = (bit.lshift(string.byte(data, 3), 8) + string.byte(data, 4)) * mul
+	max44006.green = (bit.lshift(string.byte(data, 5), 8) + string.byte(data, 6)) * mul
+	max44006.blue = (bit.lshift(string.byte(data, 7), 8) + string.byte(data, 8)) * mul
+	max44006.ir = (bit.lshift(string.byte(data, 9), 8) + string.byte(data, 10)) * mul
+	return ret
+end
+
+return max44006