APRS-XO is a tiny APRS implementation for the XO computer written by Jack Zielke KG4GJY. This activity was designed to meet the OLPC XO portion of the APRS Messaging/Contact Initiative. APRS-XO lets you report your position within the global APRS network, receive any incoming APRS messages and send any APRS messages or email. At the same time you can use the XO's browser to link to any on-line APRS system and see the local or global APRS tactical picture.

About APRS-XO icon

This activity provides position and messaging capabilities to amateur radio operators. For this activity to be useful, you will need an XO laptop and a ham license. To send messages or position reports you will need a password. If you already have a passcode for the APRS network, that is what you use here. If you do not have a password click here and follow the directions. Contact me with any questions.


APRSXO-14.xo <-- Click on the link to the left to download APRS-XO to your laptop.
Detailed directions (with photos) can be found here.
Click on the link.
Click Continue, or let the countdown finish.
Go to the Journal and click on the APRS-XO download.
The activity is now installed.

How to use

When you run APRS-XO directly (as opposed to resuming from the Journal) some very basic help appears in the two text areas on the right.
APRS-XO Screenshot

If you click on one of the buttons to select an APRS site the URI will be copied to the Journal. After that happens click on the globe icon to open the link in Browse.
The links currently are:

FindU --> http://www.findu.com/cgi-bin/symbol.cgi?icon=XA&limit=200
APRSworld --> http://aprsworld.net/
APRS --> http://aprs.org/
About --> http://zielkeassociates.com/~jack/aprs-xo/

Journal Screenshot

Fill in your callsign in the Callsign field. You can use an SSID after your callsign. ex: KG4GJY-3
If you do not have a password leave the Password field blank. Starting with version 11 if you leave the Password field blank the password will be filled in for you.

Station Comment
Your station comment will be added to the end of your position packet every time it is sent. If you edit this field you will automatically stop sending your position packets. Recheck the Beacon every 10 minutes checkbox to resume sending. Please read about the 'Beacon every 10 minutes' checkbox below.

Position Data
If you know your coordinates, enter them here in Degrees, Minutes and decimal minutes. Use the dropdown boxes to to signify N S E W. If you do not know your position enter a zip code. When you click connect the activity will try to look up the location for you. This uses yahoo.com and may or may not work.

APRS-XO randomly selects a server from 'rotate.aprs2.net' on tcp port 14580 each time the Connect button is pressed. Once connected the button will change into a Disconnect button.

Press to clear old messages from the message window. Messages currently being sent or in queue will remain in the window.

When you send a message or bulletin it will keep sending until it is acknowledged (for a message) or times out (for messages and bulletins). If you press Cancel a window will pop up listing all messages currently being sent and all messages in the queue. Clicking on a message will cancel it. The Cancel All button will cancel all messages/bulletins.

Cancel Window Screenshot

If this box is checked CQ CQ CQ From <Station Comment> will be sent to CQSRVR every 32 minutes. If the box is unchecked (or disconnect is pressed) an unregister message will be sent to CQSRVR.

Beacon every 10 minutes
Every 10 minutes from the time you connect APRS-XO attempts to send your position data and station comment. If beacon is checked the activity will send the information to the APRS network.

Please note that if you edit your information on the left side of the screen (Callsign, Station Comment, Position Data or Zip Code) the beacon will automatically uncheck itself. This will prevent a badly timed packet from being sent while you are editing. When you are finished editing recheck Beacon. If you entered a new zip code reactivating the Beacon checkbox will cause APRS-XO to attempt to change the zip code into position information. This will not change your callsign even if it was previously generated from a zip code.

Message Window
The text area below the Beacon checkbox is the Message Window. All messages and bulletins will appear here.

Below the message window are the widgets that you use to send messages and bulletins. The first textbox is for the callsign you want to send a message to. When you type in a callsign auto-complete will display all matches from the list of callsigns. You can select a callsign in the list or type a new one. You can queue 2 messages to the same person. If you get to the end of the line (67 characters) hit enter and keep going. Please note that some displays can only show the beginning of the message. To send press enter or the Send button on the right.

Status Window
Below the Messaging area is the Status window. All communication with the APRS server will appear here. Once you connect to the server the filter is set to m/300. This allows you to see all APRS packets within a 300 mile radius of your position.

The textbox below the Staus Window will send raw text to the APRS server. You can hand craft a valid APRS packet to send from here. I suggest using it to change the filter if you prefer something other than the preselected m/300.

# filter m/0 should hide all packets except for those that you send or are sent directly to you.
# filter s//A/X should only show you other XO's.


Change the title of the Activity to your callsign and location. This will make it easier to choose which activity to resume from the Journal.


Wonder what the source code looks like? Click here and find out!

The license? I have that (GPLv2) as well!

Older versions can be found in the archive.

This program is designed for OLPC software 8.2.0. It should run fine with older versions. After the 8.2.0 upgrade I had to make the font size slightly smaller and some of the text fields slightly shorter. Everything should fit on the screen of an older build but things might not line up quite so well.

Originally this program was designed to help XO users locate each other to make use of the mesh abilities. Much has changed since then. For one thing you will have a problem transmitting your location without a callsign and matching password. If you leave both the callsign and the password blank and put in a zip code instead of lat and long then press Connect the activity will automatically assign you a random callsign based on your zip code. Neat, but not useful for today's APRS network.

For Xastir on the XO take a look at http://wiki.laptop.org/go/User:Kronenpj.

APRS-XO by Jack Zielke KG4GJY

APRS Copyright © Bob Bruninga WB4APR

OLPC XO photo credit Mike McGregor mikemcgregor.com