Weather with a slice of Raspberry Pi
A lot of us have recently gotten into weather stations, thanks to Kenny, and having fun connecting them up to My AcuRite and Weather Underground. A weather net is starting to materialize. And, of course, our little Raspbery Pi s are sitting there crying "I wanna play too!".
I bought this dongle a while back. They are available for $25 alone, or $35 with accessories. It was sitting around and anxious to play with the Pi. Someone had mentioned this new program, rtl_433, and I figured this was a good place to start. Google had several good articles. But, since I can read, I started off with rtl-sdr.com/qsg. There are pages and pages of setting up your dongle in Windows. Skip down below all that garbage and get to the important part, "Getting started on Linux".
You'll see about a dozen lines to copy, paste into a terminal, and execute to bring up your dongle. They also provide a link to another Quick Start Guide.
This guide is written by Kenn Ranous, KA0SBL, and is well written with a lot more info. The only thing I noticed is that Kenn's step 6 needs a little clarification. You need to create a file containing text to remove a competing driver. The following will do that for you:
sudo nano /etc/modprobe.d/blacklist-rtl.conf
Ctrl O to save the file you just created, and Ctrl X to exit the word processor Nano.
rtl-sdg.com/qsg accomplishes the same thing differently.
This is a third link to installing the dongle drivers, and this one includes the installation of rtl_433 as well. Each post has other information included that you may find interesting and helpful.
So, grab a spare Pi, burn the latest Raspbian onto your SD, and start playing! Like always, you'll want to:
Change the password, setup WiFi, let it update, and reboot.
You'll also want to change the host name from raspberrypi, I used SDR, and turn on SSH.
You may also want to set up a fixed IP address. All of this is covered in earlier articles, see Archives.
Now that you have your Pi up and running, grab one of the quick start guides and install the drivers.You should be able to open up a terminal on this computer and enter ssh pi@sdr. You could also enter ssh pi@"whatever IP your Pi was given". You can now copy command lines directly from the article, then paste and run them in this terminal with very little typing.
Use the last guide now to install rtl_433, then reboot.
Log into the Pi again with your terminal, and enter rtl_433. Your weather data should pop up shortly! It defaults to 433.92 Mhz, auto detects and decodes your data, and defaults to putting your data on the screen. rtl_433 has a ton of options you can configure, including formatting the data output and saving it to a file. The list is at the bottom of this page.
Other articles use other programs to format the data, then populate a database or pass it onto another program. I am not up on databases, but at this point, you will have to select the proper programs to get your data into the format you need and sent to where you need it.
At this point, you have a Raspberry Pi that listens to your weather station broadcasts on 433 Mhz and presents data, in readable English, on your screen. Quite a handy diagnostic tool at the very least!
Have fun and tell us all your plans and progress from here!
Jim Albrecht K2BHM