Cheap way to measure tempeature and humidity

Hi,
since a few weeks I’m searching for a cheap (and easy) way to monitor the temperature and the humidity in my rooms.
Right now I’m leaning towards the Aeon Labs ZW100 as I already have some Z-Wave devices. What puts me of on these sensors it that they don’t have a Display.
Another way would be to use the RFXCOM binding and using off-the-shelf sensors for weather stations but the Cost for the RFXCOM Stick puts me off (100€) and I could not find any information if other sticks are compatible with the RFFXCOM binding.
Other Smarthome bridges do have nice sensors wich would fit my needs but I don’t really want to have “additional” Smarthome Stations.

Thank you in advance,
Jonas

If it matters: I’m in Germany.

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Hi,
I have made very good experience with a JeeLink controller and appropriate TechnoLine sensors. One sensor (temperature and humidity) costs around 17 EUR and the controller about 30 EUR. I placed one sensor in every room and for openHAB 2 you can find a very good bindig here: https://community.openhab.org/t/new-jeelink-openhab2-binding/15018

Kind regards,

André

Have a look at mysensors.org

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Hello,

Here is several proposals:
Program yourself: https://www.itead.cc/sonoff-th.html
DIY Wifi: nodemcu (esp8266)5€ + DHT22 4€
DIY 433mhz: atmega328p + DHT22 https://1technophile.blogspot.fr/2016/12/low-cost-low-power-room-sensor-with.html (need cheap 433mhz mqtt gateway)
DIY 2,4ghz: atmega328p + DHT22 with Nrf2401 (need mysensors gateway)
Off the shelf: Xiaomi + gateway , I didn’t verified the openhab interoperability

There is plenty of possibilities depending of the degree of DIY you want, at least some ideas

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Xiaomi gateway + sensor is so far one of the cheapest non-DIY, thanks to @Ondrej_Pecta and @pboos who are working on bindings for Xiaomi :slight_smile:

The cheapest gateway I found on Aliexpress is around 28 usd.

The battery powered temperature + humidity sensors are $10 each.

You can add I think up to 30 devices to the gateway (but this needs to be verified…) like motion sensors, door contacts and wireless switches.
Although, you need a clunky smartphone app (poorly translated to English) to get things connected.

But I thought it may be worth trying anyway :slight_smile:

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Can you access the Xiaomi sensors directly on the gateway using an HTTP call? Or do you have to go through the cloud?

Now we can read events on local network by enabling a developer mode on gateway :slight_smile:

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If you are into DIY, arduinos may be another cheap option, e.g. https://www.mysensors.org/build/temp.

You can buy an arduino nano equivalent for £2 to £3, wireless interfaces for less than £1 each, and the temperature sensors for about a £1 each. You will also need usb charger or battery pack for the arduino. The mysensors project linked above supports openHAB (see https://www.mysensors.org/controller/openhab or https://forum.mysensors.org/topic/3108/openhab-binding).

What’s more on that, MySensors binding for OH2 is soon to be released :slight_smile:

Thanks, this was the way I ultimatly went.

For the mysensors.org or the “Program yourself” Option: That is not my cup of tea - I envy people who are good with electronics and programming - but I’m not one of them. That’s why I shy away from those things.

The Xiaomi looks quiet good and cheap but the fact that the gateway communicates with some servers in the internet put me off. Nice to see that now it works without cloud access with developer mode. That beeing said: the Sensors don’t have a display so WAF would not have been as high :). Also they don’t have german Plugs as far as I see :(.

Thank you all for your assistance, it’s highly appriciated!

Regards,
Jonas

Hi,

I’m interested in the JeeLink items you went with, can you share which you used as a controller and which TechnoLine sensors you used?

Cheers,
Steve

Hi,
I initially got two “Technoline Zusatzsensor TX 29 DTH - IT”, the german Amazon Page had a lot of reviews stating that FHEM works so these should work. As the JeeLink I went with the v3c: http://www.digitalsmarties.net/products/jeelink

I did not get to test them as the JeeLink is not yet here :confused:

Regards,
Jonas

Have a look at the RFLink Gateway…
DIY cost is around 10 euros and it supports 100’s of devices and protocols.
http://www.nemcon.nl/blog2

I’ve bought a while ago the “original” JeeLink v3c from JeeLabs and I’m using the Technoline TX35DTH-IT sensors. Because they use a different data rate of 9.579 kbps you have to set in the JeeLink receiver configuration the following init command - what is now supported also in the JeeLink binding for openHAB 2:

0a 1r v

Today I would also prefer the TX29DTH-IT because with their data rate of 17.241 kbps they work directly out of the box - but in my understandig they have no further benefits.

You can find a very good overview of the sensors an the controller here (in german):

https://wiki.fhem.de/wiki/JeeLink

Cheers - I’ll take a look

I use the Technoline Zusatzsensor TX 29 DTH - IT + JeeLink Solution and they are great and cheap. Second and third I would suggest a DIY MySensors oder DIY Souliss sensor nodes.
And I prefer RFM69HW over NRf24L01+ Radios, because 868Mhz can bridge a longer distance through walls than 2,4Ghz.

I use mysensors.org, here is my cheap (<20€) battery temperature and humidity sensor (80mmx80mm):

http://www.vesternet.com/z-wave-everspring-temperature-and-humidity-sensor

I have a number of these sensors around my house. They work great and also look the part, so score high on the WAF. Although they are not the cheapest, they do fit in very nicely indeed.

Do you mind providing a bit more information about the equipment you used for this?

of course not, the parts are:

  • ATMEL ATmega328P (Arduino Nano)
  • NRF24L01+ 2.4GHz Wireless Transceiver
  • DC-DC Step-Up 0.9-5V -> 5V
  • DHT22 Sensor
  • 2xAA Battery-Holder
  • Case is a surface mounted socket

I’m using a second Set of Arduino Nano + Wireless Transceiver with a USB-Cable at the OpenHAB server (As serial gateway)

Also see:
https://www.mysensors.org/build/humidity

and

https://www.mysensors.org/build/serial_gateway

and

https://www.mysensors.org/build/battery

Greetings