Low Speed Data, GPS/DPRS and D-STAR Query...

In addition to high speed data found on the ID-1, D-STAR also supports a low speed data channel. Just like in the Packet Radio heyday, you can work "keyboard-to-keyboard" with any D-STAR radio, the proper serial interface, and either d*Chat or D-RATS. Both of these are keyboard-to-keyboard communication applications that use the low speed data channel. d*Chat and D-RATS allow text based communications between multiple stations on a simplex frequency or through a D-STAR repeater. Click on the links for more details and program downloads.

The low speed channel is also where GPS data is transmitted. Ken, W6CPA, has a guide to get you started on the ID-800.

D-STAR Query: The WA6IRC Data Kiosk

The WA6IRC Gateway supports D-STAR Query, an application that receives queries on the low speed data channel. Depending on the query run, D-STAR Query returns text on the low speed data channel representing local data or data retreived from the internet. Currently D-STAR Query on the WA6IRC Gateway provides local gateway status, a variety of local weather products and a list of eathquakes for the past hour.

To run a query, you will need your D-STAR radio and either d*Chat or D-RATS. Here are the current queries and their results. Queries start with ?D* and end with ?. Both programs insert these characters for you. For D-RATS, set your program to receive raw data.




Query Return


IRC D-STAR Repeater List


IRC Analog Repeater List


IRC Event Calendar


Current Los Angeles Weather


Current Los Angeles Area Hazardous Weather Alerts


Current Los Angeles Area Zone Forecasts


Earthquakes- Past Hour


Current D-Plus Status


Current Power Status


Play Welcome Message


Display List of Commands

Here is a sample of the reults of an earthquake query:

nc,71270661,0,"Monday, August 24, 2009 23:08:45 UTC",38.8268,-122.7672,1.4,1.10,19,"Northern California"
ci,14502116,1,"Monday, August 24, 2009 22:54:49 UTC",36.4000,-117.8605,1.5,7.60,19,"Central California"
ci,14502108,1,"Monday, August 24, 2009 22:37:00 UTC",36.3870,-117.8678,2.4,3.80,36,"Central California"
nn,00290931,1,"Monday, August 24, 2009 22:20:33 UTC",37.0890,-116.7560,1.3,2.00,35,"Nevada"


D-PRS is APRS for D-STAR. All D-STAR radios except the ID-1 offer GPS connectivity, either built-in as with the 2820, as an external GPS speaker mic for the IC-80 and 92 HTs, or by an external GPS unit for the rest. Setting up your radio for GPS can be a bit daunting, so here are some tips.

GPS-A Mode
There are two GPS modes, GPS and GPS-A. GPS-A sends an abbreviated position message, and is a bit easier to set up on your radio. It is available on the 2820, 880, 92 and 80 D-STAR radios. GPS-A requires an "UNPROTO Address" to be set. These are listed below:

GPS-A Mode Radio UNPROTO Settings











Additional GPS-A Set Mode parameters to select as you choose are: Data Extension, Time Stamp, GPS-A Symbol, and Comment. The following Digital Mode settings should be made for GPS-A:

GPS Control Mode


GPS Auto TX Timer

DV Data TX





GPS Mode
GPS mode sends a bit more data than GPS-A, and can be used with external GPS units. GPS Mode requires a specific string to be set in the GPS Message (or C1 Message). Go to the D-PRS Calculator page to determine the correct string for the symbol you choose. GPS Mode also requires that you set the GPS Sentence parameters to GGA and RMC.

For Both Modes
For both modes you will need to set RPT2 Call to the gateway, WA6IRC_G in our case. There is not really a need to beacon your position since it is sent when you transmit, so program your DV Data TX to PTT and GPS Auto TX Timer to OFF. Last but not least, set DATA SPEED to 4800 and GPS to ON.

See your manual for details on connecting external GPS units to your radio. Also take a look at VK4TUX's D-STAR page for more info. Here is a link specific to the IC-2820 and GPS. Thanks to Brian, WA6JFK for assistance in de-mystifying GPS and D-STAR.

DPRS and the ID-800

Ken, W6CPA tells us how to use any GPS with NMEA serial output to operate DPRS on the ID-800. Here's what to do:

1. Go to the set menu and change "GPS-OF" to "GPS-ON". After changing this, press the band-mode button and step through the GPS sentencing formats. You need to turn on the "RMC" format and the "GGA" format on. Leave the other formats off.

2. Go to this web site: http://www.aprs-is.net/DPRSCalc.aspx. Put in your call and the APRS symbol you want to use and calculate the symbol info and APRS check sum.

3. Take the info generated in step two and store it as a TX message in memory C1.

4. Set your radio to transmit TX message C1.

On almost any gateway enabled repeater, your position information will be transmitted over the low speed data channel as you talk and it will show up in the APRS system (such as www.jfindu.net). Here is a link to Pete Loveall's explanation which has more information: http://www.aprs-is.net/DPRS.aspx

Have fun!
Ken, W6CPA

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