MOBILE.TXT TIPS FOR MOBILE APRS USERS Document version: 8.6.3 Document dated: 2 Jan 2004. Previous was 8.3.8 of 10 Mar 99 Author(s): Bob Bruninga, WB4APR ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ NEW ITEMS: DESTINATION WAYPOINTS: New in ver 863 is the WAYPOINT for any mobile that can change its ICON on the fly. It looks like a red dot with an optional overlay character. Each station can only have one outstanding Waypoint at a time. The WAYPOINT symbol has special processing: 1) The symbol is sent by the same MYCALL that wants to define a WPT 2) The sending station manually enters his POSIT for the WPT and TX's 3) Receiving clients save the WPT POSIT with the call MYCALL-WP 4) Clients also keep a 1to1 association between MYCALL and MYCALL-WP 5) So they can maintain a line from the MYCALL to the MYCALL-WP 6) A new WAYPOINT will change the location of an old one 7) If the WPT ICON has an OVERLAY numeral #, then it is MYCALL-W# But we dont want anyone to have more than one WPT at a time! To enter a WAYPOINT on your mobile APRS radio, simply: * MENU to change ICON to "/" and table "\" (or overlays) * MENU to turn GPS to NO GPS * MENU to POSITION and enter the position for the WAYPOINT * HIT BCON button a few times until you see MYPOSIT confirmation * CHANGE ICON back to normal, and GPS to NMEA and resume normal ops. - Note this can be simplified with a PM already set up with the WPT Note: 1) APRSdos can only draw one line-of-association between mobile and WPT. Thus, only the last WPT received will show the line. 2) If a WPT is sent as an object, its NAME must be the name of the mobile (including SSID) of the mobile it is for. This will cause it to be received identically as if the mobile had sent it and so all clients will display it the same way and associate it properly. MILEMARKS were improved in ver 862. To see all the milemarks for any given interstate on your map just hit the "MM" command. The first time it will ask you for the STATE and INTERSTATE number as in VA95 for Virgnina I-95. THis is VERY handy for keeping track of fellow mobiles who do not have APRS but report their position via MILE MARKS. You can add these fellow travelers to the map as objects and since APRSdos Dead Reckons such objects, these other stations will travel along with you. Great for going to Dayton. See MILEMARK.TXT ONE-FINGER-MOVING-MAPS: In ver 837, simply pressing the M key followed by an arrow key will recenter the map in that direction. INPUT-MY-RADAR sets your airspace. You can set ALARMS to go off on ANYONE, or only SPECIAL stations, or only NEW stations. VOICE ALERT! The concept called Voice Alert is like getting a FREE APRS voice calling channel in your mobile for ALWAYS being able to contact an APRS mobile no matter what freq his voice radio is on. Its also like a radar detector for other mobile APRS operators in simplex range on the open road. It is trivially simple: Instead of turning the speaker volume down on your noisey 144.39 channel, simply set CTCSS decode to 100 Hz. This accomplishes 2 things: 1) It keeps your speaker quiet but everyone who understands voice alert knows they can contact you by voice by simply calling on PL 100. 2) It causes your outgoing packets to have PL 100 to serve as a radar ping to other Voice Alert stations in range. Conversly you will never hear anything on your 144.39 voice alert unless anotehr APRS voice alert station is in simplex range (about 5 miles max) These two make sure you will have an opportunity for a voice call to QSY to 52 or other channel for a QSO. On the interstates you pass another ham statistically about once every 10 minutes. But you never know it. With Voice Alert, you now will be aware of each other's presence AND you will have a KNOWN contact frequency. OTHER MOBILE HINTS: ------------------------------------------------------------------------ OVERVIEW: Although APRS on cars, boats and aircraft equipped with GPS is obvious, it is IMPORTANT TO NOTE THAT APRS IS STILL VERY USEFUL FOR VEHICLES WITHOUT GPS TOO! Actually, the only stations that need GPS are the ones that are lost! For this reason, the first section below will discuss the use of APRS in a vehicle without GPS. Note: Be sure to do a MAPS-OVERLAY-DIGIS before going on a trip so you can see where the digiepaters are... MANUAL POSITION UPDATING: Even without GPS, just use the map and the INPUT-MY-POS command to enter yourself on the map. If you include a course and speed, then you will also move on everyone's screen by dead reckoning. (unfortunately many new APRS clients overlooked the extreme importance of deadreckoning in APRS and objects don't move on their maps (sad)). Depending on the speeds involved and the size of the net, updates are only required when there is a significant change to course or speed. Astation moving cross country reporting via HF can set his course to 270 degrees at his estimated average speed made-good. Although he only updates his position once every few hours, because of the automatic APRS dead reckoning, his van will appear to everyone to move west giving a good approximation of his progress. Our first GPS equipped Marathon used bicycles in 1993 marathon, but in 1994 we did not even bother with the GPS's except for the TAIL. We simply monitored the voice nets, and occasionally whenever someone mentioned where the LEAD, or PACK (or any other recognizable) runners were, the APRS operator simply updated the objects to the reported locations and all APRS stations along the route could see visualy where these objects were because of the automatic Dead Reckoning. THis works beautifully because the course is always known, and the speed of the runners in a marathon is very well known, the dead- reckoned movement of these symbols between updates was actually just as accurate as GPS! (Selective Availabilty was always on back then). See MARATHON.txt. A special version of APRS can actually deadreckon objects along a given course making all the turns indicated on the map. See APRSdr.txt. MOBILE OPERATIONS: APRS was designed to make mobile operations with one finger relatively easy. The following summarizes the commands that are frequently used in the Mobile environment: G - GOTO: On any screen other than the MAP, this command will redraw the map centered on your vehicle. If you are already on the map, then GOTO puts the cursor on your station so that a single press of the PgUP/DN keys will allow you to zoom or home the map in one step. T - TRACK: Select this on the P-list. As a tracked station approaches the edge of any map, APRS will automatically re-draw the map in that direction. If TRACK mode is on, then the GOTO command will go to the Tracked vehicle. A - ALARM: Also activated on the P-list, will trigger BEEPs and cause your screen to be centered on the station if it moves. Useful to alert me when the wife is coming home so I can go to the kitchen and look domestic on her return. IMP - INPUT-MY-POS: Use to manually update your position, or change your symbol, course, speed or comments. Unless your exact location between point A and B is important, simply enter your estimated average speed, and the straight line course to B. Other stations will be able to see your dead-reckoned progress toward B and you will not have to make frequent updates. Since APRSdos also DR's your progress on your own screen, you will see the same thing that everyone else sees. You can tell whether you need to update your progress or not because each DR'ed position is posted on your screen at the same time that it is transmitted. Because of the APRSdos decay algorithm the reports will be close together initially and further apart as time goes on. In order for this DR to work on your own screen, you must not be in HSP or SPM modes. See the ALT-SETUP-GPS-OFFgps command below. If you want to see where your DR'ed position is at any time between transmissions, simply hit the space bar, and a fresh DR will be displayed. CHEAP AND PLENTIFUL MOBILE LAPTOPS: I prefer my old 8086 laptop mono- chrome LCD since it works BEST in bright sun! It only has dual flopies, but a minimum APRS system PLUS DOS will fit on a single 720K floppy. Or to have more maps, put only APRSxxx.EXE on the system floppy in A: and put all the rest of APRS and maps on drive B. Then boot with A, then change to B: and run A:APRSxxx. This will load APRSxxx.exe from A:, but it will look on B: for all its files. AUTOMATIC GPS INTERFACES See the GPS.txt file for information on the several methods for interfacing your PC to GPS or LORAN. Some useful commands are: Alt-SETUP-GPS-TIMEsync - Synchronizes your PC clock to the GPS time in the next GPS posit heard. This is important to avoid dead reckoning errors on small area maps! NOTE that this command only synchronizes the minutes, so you at least have to be in the right hour.... Alt-SETUP-POSrate - Sets both your own screen updates and the on-air transmission rates through the TNC. Alt-SETUP-GPS-OFFgps - Turns off the HSP/SPM modes without having to re-configure. This is useful if you are normally configured for HSP or SPM modes but are going to be doing manual updating. If the PC is left in HSP or SPM modes, then your local screen will NOT be updated on each DR. IF HSP and SPM are off, then each time your position is transmitted, a new DR plot is drawn. OPS-COMM-GPS - Permits you to either communicate with your GPS if it has a bi-directional port, or to monitor the TNC. This command also switches the APRS port-splitter circuit in HSP mode so that you could monitor the GPS. F6 This key is called the QRT function because it forces your speed to zero as you approach your destination so that your posits will not continue to dead reckon on everyone's screens after you turn your system off. MAPLISTS: As you enter different areas of the country, don't forget to change to a new MAPLIST.xxx for each of the 6 major regions of the country with the MAPS-CONFIG-CHANGEmaplist command. de WB4APR, Bob