LUX Meter - requirements collection

[vlast3k]

Hi Guys,

i am collecting some wishes about a LUX meter that connects to Domotica over Wifi / MQTT.
Initially it will be USB powered device.
Currently i am investigating how to make it battery powered. Goal is to last at least 1 year on 2xAA Alcaline (1.5v) cells, or even more on 2xC (Baby) cells (with the limitation that light will be checked only few times per hour, which may be not desired... so therfore the wishes collection here )

I would like to know what is the interest in this device, and what you expect it to do

Regards, Vladimir

[Sparkman]

Hi Vladimir,

I currently use a few of these: http://www.everspring.com/ST815.aspx. For me, the LCD screen is not needed, but the one important feature is that it can be configured to send updates if the change in lux exceeds a certain amount. That way it does not need to keep the radio on all the time. Having it battery powered would be very important to me. There are no outlets nearby where I would mount them and having a cable between them and the nearest outlet would be very low on the WAF.

Cheers
Al

[vlast3k]

and how fast to those react ?
In the moment you turn the light on (or maximum couple of seconds later) or after some delay (few minutes)
this will determine whether i would need a second, lower power mcu on the board or not, as the wifi chip (ESP8266) consumes quite some power

[vlast3k]

And another question - do you need the output really in LUX or also other units.. as there are sensors that really measure LUX and others that just measure how strong the light is but w/o convering it to lux (the difference is rather in the communication with those sensors and not so much in the price)

[Sparkman]

and how fast to those react ?
In the moment you turn the light on (or maximum couple of seconds later) or after some delay (few minutes)
this will determine whether i would need a second, lower power mcu on the board or not, as the wifi chip (ESP8266) consumes quite some power

The delay is about 5 seconds, which is acceptable to me.

[Sparkman]

And another question - do you need the output really in LUX or also other units.. as there are sensors that really measure LUX and others that just measure how strong the light is but w/o convering it to lux (the difference is rather in the communication with those sensors and not so much in the price)

I've only seen sensors that report in Lux and in %. My preference is Lux as % is unclear (% of what?). What other types are there?

[Bwired]

output type is no problem for me, the format does not matter.
I should be able to put the sensor also behind a window to measure the outside light intensity.
Also should be able to sense different kind of darkness.
For example:
when it just getting dark i want to close the front curtains and turn on the inside lighting
when its really dark, outside lightning and back curtains should close.

[Merdeka]

I made one using an ESP8266 (ESP-01) and a JeeNode Lux Plug.

Does MQTT over WiFi and has an HTML status page with WebSocket connection.

Info is on my site http://www.sariwating.net/2016/04/06/mqtt-light-sensor/
Including a link to the code on my GitHub

Cheers,

Timo

[r_255]

I did not made mine, but just bought it ;o) included the ldr

http://www.cnx-software.com/2015/12/14/ ... interface/
I did buy mine at ali express.

Running espeasy from esp8266.nu

Jeenode pir can also be re used perfect... 5v in ( from esp witty ) and sends 3v out on motion ( connected to a free gpio )
Nice thing on the esp witty is that there is a rgb led that i set red on motion.

I dont use mqtt, but it should be supported in espeasy to. New version of the firmware also supports local events
So you let the pir only report to your software if the ldr is below a certain level. Or in my case set the led to red if the pir detects motion.

less than 6 eu

https://plus.google.com/u/0/+RobinFrant ... =true&fd=1

[Phaeton]

I agree with bwired, output doesnt matter. I'll figure out the values I need. I'll do the same; use it behind a window to measure light intensity. I'd love battery support but I prefer more updates without batteries

[Phaeton]

Hi vlast3k, are you further with this? Im quite curious!

[vlast3k]

Hi vlast3k, are you further with this? Im quite curious!

i decided to give it a try and make it with a battery, but for this i would need some very efficient battery cirquit, especially if it has to respond with few seconds delay time.
i did some evaluations in this direction, and few additional ideas popped up that i wanted to explore (Air Quality Monitor, Plant Watering Monitor) so i had to check what they would need as well
on the other hand i am waiting for some pcbs for another project to arrive, if i have got them right this time, i would be able to reuse the idea also for this project.
in fact i ordered some parts from aliexpress for this project but now it will take 2-3 more weeks until i get them

[Phaeton]

Thanks for the update