Setting up a PacComm PicoPacket with the second serial port option for use as a dual-mode tracker is relatively simple. Hardware-wise, you need to make up a cable to attach your GPS to the second port of the PicoPacket, then configure the GPS to output the desired string(s) at either 4800 or 9600 bps. Note that many hand-held GPS units default to NO output, to conserve battery life; make sure you have "Output NMEA 0183" turned on. You then need to set the baud rate for the TNC ports to match your computer and GPS, using the BAUD command as explained in the PacComm manual. I used 4800 on both ports, for simplicty sake, since I use the same computer with Kantronics TNCs that don't have the luxury of a separate GPS port. The following is a DISPlay dump of the settings from my PicoPacket tracker. I don't have the latest software, so you won't see anything about remote operations (very nice addition) in this list: 3rdparty ON 8bitconv ON ACkprior ON ACKTime 14 ADrdisp ON AMonth OFF ASyrxovr 9 ASYFrerr 0 ASYQover 0 AS1Rxovr 21 AS1Frerr 6 AS1Qover 101 AUTOFwd OFF AUtolf ON AWlen 8 Ax25l2v2 ON AXDelay 0 AXHang 0 BBfailed 0 BBSmsgs OFF Beacon EVERY 0 EBEacon OFF BKondel OFF BReak ON BText {j} Jeff from Woodstock, IL BUdlist OFF CANline $18 CANPac $19 CBell OFF CHeck 12 CHECKV1 OFF CLKadj 0 CLKSet ON CMdtime 1 CMSg OFF CMSGDisc OFF COMmand $03 CONMode CONVERSE Link state is: DISCONNECTED CONOk ON CONPerm OFF CONRPT OFF CONStamp OFF CPactime OFF CR ON CRAfter ON CText No one home! UIMODe OFF DAYUsa ON DEAdtime 20 DELete OFF DIGipeat ON DIGISent 0 DWait 0 Echo ON ELOc OFF EScape OFF Flow OFF FRack 3 FSCreen ON FUlldup OFF FIXType 1 GPS OFF GPSTExt $GPRMC LG1text LG2text LG3text GPSItext HEaderli OFF HEALled OFF HId OFF HOMebbs HOvrerr 18 HUndrerr 1 KILONFWD ON KISs OFF LCAlls LCok ON LCStream ON LFadd OFF LFIgnore OFF LGEtchar $05 LOCation EVERY 9 LPATH APRS VIA RELAY,WIDE LTEXT L1text L2text L3text LOGonmsg ON MAll ON MAXframe 4 MCOM OFF MCon OFF MFilter $0C Monitor ON MRpt ON MSGHdr ON MSGRoute OFF MStamp OFF MYAlias NONE MY1alias MY2alias MY3alias MYRose MYcall KA9VNV-12 MYPcall NEwmode OFF NODetext NOmode OFF NUcr OFF NULf OFF NULLs 0 Paclen 128 PACTime AFTER 10 PARity 0 PASs $16 PASSAll OFF PErsist 63 PMs OFF PMSConn 0 PIdcheck OFF PPersist OFF PRefix $00 RCVDFrmr 0 RCVDIfra 0 RCVDRej 0 RCVDSabm 0 RCVDRNr 0 REDispla $12 REMSysop OFF RESptime 0 REtry 10 RTCSync OFF RXAbort 64639 RXblock OFF RXCount 20721 RXErrors 39343 RXLenerr 0 RXResync 1 Screenln 0 SEndpac $0D SENTFrmr 0 SENTIfra 0 SENTRej 0 SENTRNr 0 SLOts 2 SLottime 50 STArt $11 STExt STOp $13 STREAMCa OFF STREAMDb OFF STReamsw $7C TKILlok OFF TRACe OFF TRFlow ON TRIes 0 TXCount 19823 TXdelay 15 TXDELAYC 12 TXFlow ON TXQovflw 0 TXTmo 0 TXUifram ON UIBeacon OFF UILOc OFF Unproto APRSW VIA WIDE3-3 LSLOT 60 LSLOTMIN 0 LSUBSLOT 0 LSUBNUMB 0 USers 1 Xflow ON XMitok ON XOff $13 XON $11 There is nothing particularly magical about most of these settings; in fact, most are right out of the PacComm manual. Those that are important, especially for operating both with and without a computer, are as follows: LOCation Every 9 (send location string every 90 seconds) ELOC OFF (don't echo location string to computer port) LGEtchar $05 (send computer location strings when ^E received) GPSTExt $GPRMC (all caps, use $GPGGA if your GPS sends it) LPATH APRS v RELAY,WIDE (generic path, works most networks for mobiles) BText {j} ... (adds symbol, see APRS DOS SYMBOLS.TXT file for details) Beacon Every 120 (cleared by APRS programs, unfortunately) At this point, the Pico should operate as a stand-alone tracker; plug in the GPS, attach the radio, and turn everything on, and it should show up on your map as soon as the GPS has a signal lock. To operate as an intelligent tracker, i.e., with a computer running a version of APRS attached, there are some small details to take care of. APRS DOS, version 7.9 and above, should work fine, so long as you have a GPS license number from Bob. Prior versions had some problems with "losing" the PicoPacket after a while, and simply not doing anything useful. You do need to tell it when you set the program up that it is a PicoPacket, and set up the GPS input as being an "HSP cable", so that APRS knows to send a ^E periodically to read the GPS position. You will also want to have APRS read the GPS position twice as often (or more) than your normal beacon time (the LOC parameter), so that the TNC never sends a "raw" position report (the ^E character resets the LOC timer each time it is seen). One caveat with DOS APRS... when you shut it down, some versions leave your BText set to your position at the time, plus "APRS QRT hhmm". This is set each time APRS sends a position report, so that it gets sent even if you don't want it to be. Either set your Beacon time to zero (disabled), or add a line to reset your BText to RESTORE.TNC in the SYSTEM directory, although that doesn't work with all versions. Failure to do this will your position to "jump" to where you shut off APRS, then back to your real position, each time your beacon is transmitted. WinAPRS works a little differently. To make it ready for use with the PicoPacket, you need to first open the Settings/Serial Port menu, and click on "Pico ^E" on the VHF TNC; this automatically checks "Allow GPS" also. Then, open Settings/TNC, and click the "Pico" button. You will note that several settings are filled in; clear every line below Command 5. Those commands will disable the automatic reversion to a stand-alone tracker (note: this MAY apply to MacAPRS as well, but I can't say). You can now open the VHF TNC, and WinAPRS will start getting its position from the GPS. LIke DOS APRS, WinAPRS has a "gotcha" for smart trackers: The availability of GPS information does NOT change the location set in the Settings/Station menu, so your first position report will ALWAYS be whatever you set there when you start WinAPRS. I have discussed this with Mark Sproul, and it is hard-coded into the Win/MacAPRS Initialize TNC code. He is aware that it is a problem, and will be looking into the situation as time permits. To put APRS+SA into Ctrl-E Polling (Pico Mode in older versions), on Main Parameters tab of Setup, put Port 1, the TNC port, into Pico mode. Adjust the GPS update rate as desired. Note that APRS+SA will poll the Pico with a Ctrl-E before transmitting a position so as to always have the most recent position. The GPS update rate is only used to determine position to all other APRS stations. File updated 8/1/98 to add APRS+SA info; Thanks Brent! Copyright 1998 Jeff KA9VNV