AVR Ethernet Weather Station


Guido Socher
build this Ethernet Weather Station project that uses an AVR microcontroller to process data from weather sensors. Software and schematics are provided.

“Using an add-on card to the already existing avr ethernet board we build a weather station. That is a weather station with a build-in webserver.

My original plan was to have sensors for temperature, air pressure and wind. I started a prototype and it worked very well except for the wind measurement part. I have written a separate article about it: wind-vane-ver01.shtml. I plan to improve the wind measurement hardware and add it at a later point in time.

For now the weather station has 2 temperature sensors and an air pressure sensor. It works reliable and precise even after several month of testing.

For the sensors we will use:

* For temperature measurements: LM335. This sensor is cheap and has a linear curve over a wide temperature range. This will give us very accurate temperature readings over a wide range. The accuracy will be almost constant over the whole range.

* A Motorola/Freescale MPX4115A absolute air pressure sensor. This sensor is already calibrated at production time. The MPX4115A is not made for out-door use but that is not a problem. The circuit can be in a save and dry location inside the house as the air pressure is exactly the same inside and outside the house.”

11 Comments


  1. They sell weather stations in kit form that do this, but trust me when I say they cost an arm and a leg.

    Here in the United States, a lot of ham radio operators set up weather stations at their houses and make the data available on the packet radio network. This usually is accompanied by GPS coordinates so you can easily make a composite of the weather happenings in your area.


  2. Hmm… make for cheap what big companies sell for lots. I love DIY!


  3. Wonder how hard it would be to add a humidity sensor onto it, GJ to Guido either way


  4. LiesOfXIII: It probably wouldnt be hard at all. Basically, I think it would just involve allocation of another IO pin from the microcontroller to the sensor IC output.


  5. It’d be cool if you can access the server, and change the temp of the house according to the readings provided.


  6. So, what would the cost to put this bad boy together?


  7. Ptr: I would imagine you could set something or another up with CGI scripting on the webserver. It wouldn’t be hard to change thresholds that way. We did something similar with a web interface to a radio repeater we built. It was just a regular computer, and not an embedded webserver, but it is definitely the same school of though.


  8. Interesting project… but somebody knows about something similar but that transmits the data via GSM? I need it to monitor a sensor 15 kms away, with no computer nearby… or even a simple plug


  9. But it seems that he is accessing the station using WAP and an apache server. I can’t do it that way because I won’t have any computer, my weather station will be in an open field remote location, with no wifi or electric power connection.
    I want a solution that, for example, using a mobile phone directly attached to the microcontroller sends a SMS text message to another phone when the temperature reaches a predefined value

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