WY1U's D-STAR Info Page

D-PRS is the act of converting Icom GPS information generated by Icom D-STAR radios in GPS mode into TNC2 formatted APRS strings. It is important to note that D-PRS is not a protocol but a conversion specification. - Peter Loveall AE5PL

GPS MODE

GPS mode uses a 3-line format and a calculated simple XOR checksum for the identification line.

D-PRS Setup for ICOM D-STAR radios using GPS mode
Refer to the radio's manual for specific GPS setup information.

Radio Configuration:

Select GPS TX to GPS or DVG mode depending on model of radio.

Enable $GPGGA and $GPRMC GPS sentences only. (Both of these GPS sentences provide position while $GPRMC provides speed and direction, and $GPGGA provides altitude).

Now use the D-PRS Message Calculator. Enter the D-STAR callsign that you will be using. (If you're using an SSID, make sure that it is in the eighth position and do not use A, B, C, D, G, S, zero, or space).

The GPS message can be whatever you'd like, up to 13 characters (ie: JOE'S TRUCK). Letters are caps only.

Enter the contents of the box "Input into TX Message C1:" into your radio. (GPS message on the IC-2820 and IC-91AD, TX message C1 channel on the ID-800H, TX GPS Message on the ID-80AD & ID880H). Be sure to enter the correct number of spaces between the symbol code and the text/checksum.

Set the automatic GPS message transmission to OFF .

Set your RPT2 in the callsign menu to allow for gateway operation by adding the letter 'G' in the eighth position. (ex: AA1HD G).

Make a "successful" transmission through your local D-STAR repeater with gateway access.

You should now see your callsign and icon as entered above, along with your current location coordinates under Last Heard on APRS. If you don't see your callsign....carefully re-check the above steps and refer to the additional notes below.

Additional Notes:

While any radio is in either GPS or GPS-A mode, it cannot be used for standard low speed data.

Refer to the radio's manual for specific GPS setup information.

The GPS-A "format" does not support altitude (/A=000121 for instance).
For your altitude to be seen, you will need to run in GPS mode with the RMC and GGA sentences enabled.

You will not not show up if the GPS sentence indicates the GPS is not in lock. On the IC-2820 display, the GPS icon should not be blinking. Be sure your GPS antenna is in the clear and far enough away from the radio's transmitting antenna.

Be sure you have the correct number of spaces between the symbol code and the text/checksum.

You must set your RPT2 to allow for gateway operation otherwise you will not be gated to APRS-IS.

Make sure that the radio is in GPS mode and not GPS-A mode. (IC-2820H display shows DV-G in upper left corner of display).

If you're using an SSID, make sure that it is in the eighth position in your radio's callsign memory (ie: WY1U _ _ _ M)
*Due to D-STAR repeater design, do not use A, B, C, D, G, S, zero, or space.

On capable radio's, the position display of a received signal is available only if the transmitting station is using GPS mode in which RMC and GGA sentences are enabled.

GPS-A MODE

Icom's GPS-A mode uses a one line format and includes a CRC.

D-PRS Setup for ICOM D-STAR radios capable of using GPS-A mode
Refer to the radio's manual for specific GPS-A setup information if available.

Radio Configuration:

You do not need to set a GPS message per the D-PRS Calculator page.

Set UNPROTO to APInnn,DSTAR* (where nnn is the first 3 digits of the radio model number. See table below).

In the case of the handhelds (only 2 digits), you may optionally use the first character following the model number (92AD would be API92,DSTAR* or API92A,DSTAR*).

GPS-A Mode
UNPROTO Settings
Radio	UNPROTO
IC-2820	API282,DSTAR*
IC-80	API80,DSTAR*
IC-92	API92,DSTAR*
ID-880	API880,DSTAR*

Note: GPS-A does not pass altitude information to APRS-IS.

For more info on D-PRS, please visit AE5PL's D-PRS page.

Waterproof external GPS Antenna for IC-2820

The Gilsson part #MCX Amplified GPS Antenna with 90 degree MCX connector can be used in place of the "non-waterproof" ICOM GPS antenna that comes with the UT-123.

Notes:

You will also need a Female-Male MCX adapter that has a straight MCX male connector body that will fit thru the case of the IC-2820 into the external GPS jack.

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