DIY temperature, hygrometer and humidity waterproof sensor 433Mhz low cost low power

I have build an external waterproof sensor integrated with openhab based on Atmega328p (arduino heart).

Main characteristic is low power (6 micro amps when not sending data) which theoreticaly give a life of around 8 years to the sensor (I’m lazy don’t want to change batteries and don’t like to waste energy :slight_smile: ).
It is sending temperature, humidity, soil hygrometry and battery voltage every hour so as to monitor my garden environement.

Here is how it looks like into OH:

The RF used is 433Mhz with emitter powered only when sending data (same thing for the sensors), data is sent as a numerical value to a 433Mhz gateway that forward the data by MQTT with ethernet to OpenHAB.

Data are persisted, here is some views.


Hi @1technophile

very cool project. Thanks for sharing with us.
I’m planning something similar to that but fortunately I don’t need to care about power consumption. So I can use a ESP8266 to directly communicate to our WiFi. However one thing I’m interested is your soil moisture sensor. What are your long term experiences about it? I’m planning to use this sensor (actually bought it already) as I’ve heard that the capacitive approach seems to be much better in terms of durability.


Hi @fog the soil moisture sensor is working since 2 month now, I can’t say that I have a long term experience unfortunately. Here is the data coming from this sensor in particular:

Working good at the moment and no sign of aging but interested on your feedback with the capacitive approach.

Hi @1technophile I will give feedback as soon as I’m done with it but I guess it will take some time because I still wait for some components and stuff. What I’ve heard is that after a while the sensor starts to corrode and then the values might get inaccurate.

Hi, I have started a new topic to get feedback from the community on what is a good working solution for stand alone environment sensor (temperature, humidity, etc)

It needs to be able to log data

What combination of sensors, GW/hardware, OH binding are YOU using?
do you regret your choice ?
for what price?