Weather Radio Alert Computer Interface & Scripts



This simple project will show you how to modify and interface the Realistic WeatherRadio Alert III to your Linux computer. It interfaces to your parallel port and the Linux software patch watches pin 10, which goes low when the National Weather Service sends it's alert signal. At which time a shell script is forked and you can configure it to; send a packet radio or internet message with the latest advisory, dial pagers by setting up a script with minicom, speak the alert over a two radio utilizing a voice synthesizer package, or anything else you can think of.  (Please make sure in your PC BIOS that your parallel port is set to "standard" or "compatible" mode, and not to ECP, EPP or bi-directional.)

This is clearly allowed under Part 97, as well as periodic retransmission. See: FCC Part 97.113.e Prohibited transmissions that states:  No station shall retransmit programs or signals emanating from any type of radio station other than an amateur station, except propagation and weather forecast information intended for use by the general public and originated from United States Government stations.

While interfacing to a Linux computer was my original use, I should note that same hardware mod to the weather radio can be used to interface to a repeater controller.  Just tie the logic high output of the modified receiver to a controller input.  Program a voice slot to the effect of  "Weather Radio Alert, Check 162.550 MHz for information ," that will go off when the controller input is triggered.

Unfortunately I haven't found a weather decoder with SAME technology at Radio Shack that will work similarly.  Most of the SAME ones I've tried to use require physical acknowledgment/reset before they will re-trigger their alarm.  For interfacing a weather radio with SAME technology I suggest one looks at Computer Automation Technology's WD-100, or WX-2000.  The WD-100 is a digital decoder that connects to a VHF receiver and responds to Specific Area Message Encoded (SAME) alerts transmitted by the NOAA.  It's designed to be compatible with just about any repeater as it's a stand alone supplemental controller.  The WX-200 has an integrated weather receiver.  It also can periodically broadcast the nature of the alert using it's own voice synthesizer.

Modifying a Radio Shack Model #12-251 Weather Radio for Connection to a Repeater Controller:

Getting back to the Linux side of things here are a couple other applications that have developed that interest me:

The first is a series of scripts to generate weather reports on your IRLP node.   The second is much like the first but generates them for an Asterisk PBX.  The both work very similar.  They download text products from sometimes as METAR's and convert the reports for your city to human readable text.  Then they convert them using the Festival speech synthesis system to create a playable .MP3 or .WAV


I have often thought it would be nice if there was an open source (soundcard/ FOB based) SAME decoder solution.  One could dedicate a cheap USB sound FOB to a receiver parked on their NOAA weather radio frequency that would site and decode any SAME data bursts.  I am thinking for interfacing to repeaters to provide custom weather alert signaling.

It does appear that software to decode SAME data exists, just not open source.... Yet  A SAME software decoder would benefit projects like thelinkbox, and asterisk app_rpt as well as other projects.

Greg Hewgill, KD5VCU has a nice start on a FOSS decoder:  This might be a good place to start tinkering.

Get local weather conditions: - Original shell script to grab decoder metar style weather and speak them humanly
- Modified for asterisk.
- Modified for IRLP
- Sample output file (using Cepstral voice) - Text to speech hazardous weather check and report script


IRLP WX Add-on Applications:

irlp_wx-1.3.0.tar.gz - VK WX beacon by VK2XJG. May give ideas for other users. (Oct 2002)

metar_wx-1.0.1.tar  - Version 1.0.1 of metar_wx A script that uses Perl to get weather data for almost any airport around the world. and plays it on your node. Version 1.0.1 fixes two word site name bug.  (Dec 2002)

wx_rpt.tgz  - This tarball contains the scripts and file necessary to automatically generate weather reports on your IRLP node. NOTE: THIS IS ALPHA GRADE SOFTWARE. It will require that you have VERY good knowledge of Linux, bash and Perl coding. It is being offered at this time with NO offer to help you get it installed and working. It WILL NOT work out of the box. I may provide pointers but that is about all at this time. See the README file for more information. Good Luck!  OK: RH9 and FC3 (From KC6HUR scripts)

speak_temperature-latest.tar.gz  - This script announces the temperature using a concatenated voice. The temperature is obtained via a Dallas DS1820 1-wire sensor attached to the nodes serial port. digitemp is used to read the sensor, a precompiled static digitemp binary has been included for convenience.  (From VA3ADI 2002)


Asterisk Weather Add-on Applications:

Stream GB WX - Define an extension to stream from an internet source


Useful references:

fmh1.pdf - This is the official manual from the Department of Commerce/NOAA; Office of the Federal Coordinator Meteorological Services and Supporting Research, titled Federal Meteorological Handbook No. 1 Surface Weather Observations and Reports and is the manual which provides the specifications for coding/decoding the information in the METAR reports. FMH-1 is the guide used in developing the metar2text program.

NationalWeatherServiceInstruction10-1712.pdf - Operations and Services Dissemination Policy NWSPD 10-17 NOAA Weather Radio (NWR) All Hazards Specific Area Message Encoding (SAME).  Useful specifications guide for WD-100 and other operations.