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Topic: Weather Station (Read 994 times) previous topic - next topic

gjmiller

For my first project, I'm looking to build an Arduino-powered weather station for my home. So far, the design consists of two parts: an outdoor module and an indoor module.

Both modules will be able to:
     Measure temperature
     Measure humidity
     Measure barometric pressure

The outdoor module will be able to:
     Send its measurements to the indoor module
     Withstand weather and other adverse conditions
     Be powered by battery, possibly with a solar assist

The indoor module will be able to:
     Display measurements from both modules via an LCD
     Preferably with a button to switch between the display of indoor and outdoor measurements
     Provide current measurements to users via a web server over wifi
     Submit historical measurements to an online service for trending and graphing
     Be powered by a wall plug

As far as parts go, I've figured on:
   
Indoor station
     - Arduino Mega 2560 R3
          - Power isn't that much of a concern since this station will be wall-bound.
          - I assume that the WiFi, XBee, LCD, and other libraries will take up a good chunk of memory on their own and my own code                will add to that so I'd feel better using an Arduino with some more memory.
          - Given all of the things I intend to hook up to the Arduino, I feel that I need a good amount of pins on it.
     - Adafruit CC3000 WiFi Shield with ceramic onboard antenna (http://www.adafruit.com/products/1491)
          - Has a micro-SD slot on it, perhaps to hold configuration info
          - Can be configured via iOS or other phone
          - Has a prototyping area for weather sensors
          - Pins: +5v, GND, D3, D4, D5, D10, D11, D12, D13
     - XBee 1mW Trace antenna Series 1 module (https://www.sparkfun.com/products/11215)
          - with XBee Shield (https://www.sparkfun.com/products/10854)
          - I intend to use XBees in both modules to connect the them so the outdoor module can send its measurements to the indoor module.
          - Pins: D0, D1
     - For display, I think I'd be happy with a 16x2 LCD, but I'm unsure as to whether I could or should use a shield for the display. I have a feeling that wiring up a display without the shield gives me more flexibility when it comes to packing all of the stuff into some sort of case. I am somewhat partial to this (http://www.adafruit.com/products/823) though.
          - Pins: Dependent on choice of shield vs. no shield. The Mega should have enough pins to handle whatever I choose though.

Outdoor station
     - Arduino Micro
          - This station will be battery powered, so I'd like something smaller and less powerful for this station. I also only don't need to utilize WiFi or a display so I don't need a ton of pins, only enough for the XBee and weather sensors.
     - I can't use the XBee shield (or at least, I don't think I can…), so I think I'll have to wire up the XBee module right to the Micro.
     - I'm not sure what I'd need for power. Would a standard set of AA batteries or a 9v work here? Would I be better of with a lithium polymer battery? It gets fairly cold here during winter so I'd like something that's not going to totally die in the winter time.

Weather sensors
     - Sparkfun sells a weather shield that has temperature, humidity, and barometric pressure sensors, but I think I'd rather break those out away from the other components on both stations so they're not affected by any heat that's given off by them. Is this a valid concern?
     - If it is, then I intend to use:
          - BMP180 for pressure (http://www.adafruit.com/products/1603)
          - DHT22 for humidity (http://www.adafruit.com/products/385)
          - Both of the sensors above have temperature sensors on them, so I suppose I have my choice of the two. Does one perform better than the other?

I don't have any firm ideas about cases for either station. I like this one (http://www.instructables.com/id/Arduino-weather-station/step10/Buidling-the-Transmitter/) for the outdoor station, and this one (http://www.instructables.com/id/Plotly-Arduino-Data-Visualization/step4/Building-the-Enclosures/) for the indoor station, although I would like it to actually surround the components entirely.

Is this feasible given the parts I've chosen and the assumptions I've made ? Is there anything I should substitute in place of what I have here?

Pauly

I did a similar project using Jeenodes.  Wireless and Arduino all in one. http://moderndevice.com/product/jeenode-v6-kit/
Dead simple to use.  http://electricprojects.wordpress.com/2014/01/05/jeenodes-weather/
Right now, mine just goes to an LCD screen, but there is a Jeenode on a USB  stick so you can get the data into your computer.

I have my outdoor sensors in a plastic box inside a Stevenson Shield - http://en.wikipedia.org/wiki/Stevenson_screen
The inside LCD screen & Jeenode are in an old cigar box.

Looks like you have done some research.  I'm not sure how a WiFi shield and an Xbee would work on one Arduino.
Make sure to check for any pin conflict on all the items you want to add.  I would start with sensors first and get them to work, then work on getting the LCD screen to work next, then worry about other stuff later.
Good luck.

gjmiller

That's a good thought. If the shields interfere with each other, I might have to move the Wifi as a breakout board instead. If their antennas interfere, then maybe I'll need one or more external antennas.

vteedesign

There is a near identical project on openhomeautomation.net  in which it uses xively to host all your data. I highly recommend the tutorial as it is very easy to follow and results in an excellent finish product. on the xively website is a similar tutorial.


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