Wednesday, February 26, 2014

Remote Garden Monitor Plan

The following highlights the general plan for the Remote Garden Monitor.

Remote Garden Monitor Plan

Review of the goal:
Be able to know garden weather/conditions remotely (ideally from web, accessible anywhere)

No power, internet, and garden is ~1.6 miles from my home

Method to accomplish this:
-home made weather station built upon Raspberry Pi
-Power via Solar
-long distance transceiver radio (dnt900) used to get data from garden to my home

Project Risks:
-Weather proofing
-Heat management
-Solar/Battery able to run components with multiple days of bad weather
-Long distance RF radio link stability/ability
-Nuances of each sensor (how to get weather data)
-Posting data online (need to get familiar with languages/APIs to do this)

To get data from garden I will  run a base station (at home) with a RaspberryPi connected to a dnt900 radio (PDF of datasheet), and a similar setup in the garden (what I am calling the Remote RPi).

I have choose dnt900 radio's due to their potential long distance capability and the data-rate should be sufficient for my weather sensor data. I did spend some time comparing options at Spark Fun's wireless guide which I found very helpful as well (even though I didn't use any options they provided).

I plan on using the setup and instructions almost identical to what is found here  I have already purchased from inMojo here the two RPi900 adapters for the base and remote Raspberry Pis (along with the dnt900 from RFM here).

The Remote device will have all the weather sensors running on it, mostly via i2c. (For simplicity, and to leverage other work I've seen across the web.)

The dnt900 radios (when configured) "link-up" independently of the Raspberry Pi. Matthew Hollingwoth, maker of the RPi900 has also created a line discipline to easily control the dnt900 radios from the Raspberry Pi, found here: dnt900 line discipline, and over-viewed here. Also found on Mathew's  rpi900 site is one of the best Point-to-Point (PPP) protocol setup guides I have found on the web. Using that guide the dnt900 radios, via the RPi900 boards will interface with the Raspberry Pi's and allow the remote radio to be network accessible via PPP over the RF connection.

The remote weather station will take measurements and forward them via the base station to the internet. (Currently planning the  Xively Service to be the recipient, I will then pull data from Xively to my site, perhaps set critical twitter alerts via Zapier  or simply monitor my own Xively feed.)

My garden is a plot is within a larger community garden. Ultimately I want to share my weather data with everyone else in the garden-  so I will almost definitely  set up a website to facilitate that. On the very off-chance anyone else wants a sensor in their garden the dnt900 radio's would support that as well. (other radios would just connect via my remote.)


Sunday, February 23, 2014

not so-little project to access a weather station miles from home

A couple months ago after getting comfortable with my Raspberry Pi, and thinking about my upcoming gardening season , I got the idea it would be nice to have a weather station in my garden. Not exactly a revolutionary idea, except the fact my garden is almost two miles from the house with no access to utilities.  I also had recently been experimenting with the RPi900  (using the DNT900 transceiver ) , given it's specs, and my general RF knowledge I decided early this would be my initial approach.

Fast forward to today and I am midway through the project to make it a reality. Along the way I have started to leverage some interesting technologies (hardware and software), and continue to be impressed with the vastness of the weather station community (and those with impressive hardware or  software knowledge shared online.)  My skillset is broad, but shallow (classic 'Jack of all trades, master of none'), encouraging me to heavily leverage others work. I'll link to all the sites I found helpful along the way; so for I've found I rarely depart from the great references I find.

As I got deeper into this project (to have a distant remote weather station), it became clear it would be helpful to me (and perhaps others) to document the process  and progress.  Since this is a very much in-progress project (and subject to a few more cycles of trial and error), my posts are not going to be a step-by-step guide. Time permitting, when the project stabilizes abit more I will attempt to circle back and summarize it all.