Tripmate Information File Version 0.0 12/08/96 Compiled by Eric Cottrell from his observations and input from numerous sources on the APRSSIG mailing list and sci.geo.satellite-nav newsgroups. This my first FAQ so I welcome additions and suggestions at: eac@shore.net. It was bound to happen sooner or later. In early November 1996 I got an ad from DeLorme for Street Atlas 4.0 and in the flyer they had a page on their Tripmate package. I purchased one. I downloaded the New England area onto my laptop and the moving map display is neat. DeLorme has a lot of information on their WWW page. See http://www.delorme.com for more information. This file only addresses the GPS receiver unit and not Street Atlas 4.0 issues. Trademarks and Servicemarks mentioned belong to their respective owners. 1. WHAT IS TRIPMATE? Tripmate is a GPS receiver package with a Street Atlas 4.0 CDRom! It is a small yellow oddly shaped plastic box. The bottom comes off to reveal a battery holder in one half and a metal plate covering the electronics in the other half (held in place with glyptol covered screws). It takes four AA batteries. The manual indicates battery life of 12 to 16 hours. There is a power adapter kit for powering the GPS receiver through the cigarette lighter or laptop (Available in December from DeLorme Price: 39 USD). Some features: NMEA-0183 protocol (with a non-NMEA initialization sequence needed) 12 channel L1 C/A-code receiver Internal passive patch antenna (No external antenna connector 8-<) Overdetermined Navigation Solution The picture of the unit shown on the box is about half size. There is just a serial cable coming out of the unit and there are NO controls on unit. NMEA is outputed as RS232 using 4800,8,N,1 communication parameters. No hardware handsaking is used. 2. HOW DOES IT PREFORM? The unit does not have a RTC or backup the ephemeris, but the cold start search time seems good. It does remember last position and the almanac. The software on the computer sends date/time/position information after the unit powers up and this really speeds up the search. The unit reaquires satellites reasonably fast. It seems to have 12 parallel channels as it handles signal dropout in urban conditions very well. 3. WHO MUCH DOES IT COST? If you have a special offer from DeLorme the price is 125 USD. You can get the special price when you call DeLorme by giving the serial number of you existing DeLorme PC product. DeLorme's regular price is 150 USD. Add 5 USD to the above price for Shipping and Handling. Some computer stores carry the unit with Computer City having a special for 130 USD. Seen at Microcenter for 150 USD, CompUSA for 177 USD and Tiger Software for 199 USD. 4. ARE THERE ANY CONTROLS ON THE UNIT? No. It is just a yellow brick with a serial cable. 5. THERE IS NO ON/OFF SWITCH, HOW DO I TURN IT ON? The power is turned on by asserting DTR on the serial port. DTR is generally only asserted when the serial port is being used by a program. 6. CAN I PLUG THIS UNIT INTO MY 13.6 VOLT DC POWER SUPPLY? NO!!!. The unit appears to be designed for 5 to 8 volt input. The capacitors in the unit are rated at 10 volts and the DC power chip can handle up to 11 volts. You never run capacitors at their rated voltage. A 7.2 volt nicad battery pack has been successfully used with the unit. 7. I HAVE A THREE DAY DRIVE ACROSS THE US, HOW CAN I POWER THE UNIT FROM THE CAR? Method #1: Purchase the DC power adapter from DeLorme. Method #2 (for Homebrewers only): Pin 9 of the serial port goes to the center pin of the power plug. It is possible to build a inline serial adapter that has a 6 or 8 volt regulator built in that feeds 6 or 8 volt power up pin 9 of the serial plug (do not connect to pin 9 on the laptop side). Jumper the center pin to the positive power pin on the unit. Alternate Method #2: The 6 or 8 volt regulator mentioned above can also be put in the base of the unit with the regulator input connected to 12 volts fed up pin 9 of the serial plug to the center power pin and the regulator output connected to the positive power pin of the unit. A 5 volt regulator may also work in the above examples. !!!! DO NOT FED MORE THAN 10 VOLTS TO THE POSITIVE POWER PIN. !!!!!!! 8. CAN I USE IT ON MY NEXT HIKING TRIP? Only if you carry along a laptop or palmtop with proper software. 8->. 9. CAN I MOUNT IT ON THE ROOF? The case is gasketed, but it comes only with rubber feet. The manual says to put it on the dashboard. It may be possible to epoxy a magnetic mount to the bottom, but it may be too big to be held by a magnetic mount. It is not low profile! 10. CAN I USE THIS WITH OTHER MAP PROGRAMS? The documentation says that it can only be used with SA 4.0 and Map'N'Go 2.0. The SA 4.0 CD has Map'N'Go 2.0 drivers for the unit. When Tripmate powers up it sends three NMEA messages (PRWIRID, GPRMC, and PRWIZCH) then keeps sending a "ASTRAL" string.It requires the computer to respond to the "ASTRAL" string by sending a "ASTRAL" string to the unit. After this exchange the unit works like a normal NMEA unit. This limits it usefulness with other products (but see below). 11. CAN I USE IT TO VIEW OR LOG NMEA SENTENCES TO MY DISK Yes. Due to the initialization sequence mentioned in the "CAN I USE THIS WITH OTHER MAP PROGRAMS?" section the current NMEA viewers/loggers will not work. However I was able to use the windows terminal program to display and log the raw NMEA to disk. I programmed one of the function keys to "ASTRAL^M" and press it on power up when the ASTRAL string is sent by the Tripmate. Make sure flow control in the Communication settings is turned off. In the UTIL directory of the Street Atlas 4.0 CD there is a utility called Tripmate.exe. It is a display program that interpets the NMEA output of the Tripmate. The program is documented on DeLorme's WWW Site. This program only runs on Windows 95. 12. WHAT NMEA SENTENCES DOES IT OUTPUT? Generic: GPRMC, GPGSA, GPGGA, GPGSV Proprietary: PRWIRID Receiver Id PRWIZCH Zodiac Channel Status 13. CAN I SEND COMMANDS TO THE RECEIVER? Yes. Unfortunely I have yet to receive the serial specifications. I have information that a number of commands are possible. The only commands I do have will control the output of various NMEA sentences. $PRWIILOG,RMC,V,,, Turn off GPRMC messages. $PRWIILOG,RMC,A,,, Turn on GPRMC messages. $PRWIILOG,RMC,A,T,10,0 Turn on GPRMC messages and output every ten seconds. I would only use the on and off commands as the receiver will remember the settings if you change it and cycle the power. I found I can control the messages GSV, ZCH, RMC, GGA and GSA (Just subsitute for RMC in the above example) . This command will not force output if the message is not valid (GSV with no almanac data). It just controls how often the message is outputted when valid. The parameters for use with DeLorme software seem to be set to output the RMC, ZCH, GGA and GSA messages every second and the GSV message every two seconds. 14. CAN I USE THIS FOR RADIO AMATEUR APPLICATIONS? Yes it is useful for APRS and Packet applications. There are two methods to hook the Tripmate up to a TNC. Method #1 is to set the GPSINIT parameter (or Equivalent) to "ASTRAL". The Tripmate has to be powered for several seconds before the TNC can send the GPSINT string. Method #2 is to jumper pin 2 and 3 on the Tripmate serial plug and connect this to the serial input on the tnc. Do not connect the serial output of the TNC to the Tripmate. This will cause the Tripmate output to be fed back to the Tripmate and when it sends the ASTRAL string it will get the proper response. The next version of WinAPRS is scheduled to have Tripmate support. 15. WHAT KIND OF GPS ENGINE DOES IT USE? It uses the Rockwell International Zodiac chipset. Tripmate appears to be a scaled down version of Rockwell's JUPITER board. Zodiac is a two chip GPS chipset. One chip is a RF front end and the other is a DSP and microprocessor that can handle user interfacing, etc. It is designed as a low-cost 12 channel GPS receiver. 16. DOES IT HAVE A 1PPS OUTPUT? Not directly. There is a very tiny unconnected pin on a chip that has 1 PPS but you need to be comfortable with surface mount components to use it. Remember removing the plate to get at the electronics voids the warranty. Hopefully I can get more information on how to use this. A bit of confusion is that I have conflicting information about the 1 PPS occuring on the UTC second boundary. Using NMEA it appears to actually be 1 or 2 seconds slow. However there is a company using the Rockwell Jupiter board on a PC timing card and the description indicates that 1 PPS occurs on the UTC boundary. It could be an option that the Tripmate does not have or is only available when using Rockwell protocol. 17. DOES IT USE ROCKWELL PROTOCOL? Unfortunely I do not have the complete serial I/O specifications. I have seen indications that a NMEA command can be used to switch over to Rockwell protocol. Option resistors can be changed to power up in Rockwell protocol as well, but the experimenter should be comfortable with surface mount. Remember removing the plate to get at the electronics voids the warranty. Hopefully I can get more information on how to use this. Rockwell protocol is binary and uses 9600,8,N,1 parameters. It allows for more control over the receiver,like Datum Selection. It requires software capable of decoding the binary data. 18. DOES IT USE DGPS? Not directly. The Zodiac chipset is DGPS capable and has a second serial port for RCTM input. The problem is the same as with the 1PPS or Rockwell Protocol. The board appears not to bring out the second serial port to a readily useable point. Remember removing the plate to get at the electronics voids the warranty. Hopefully I can get more information on how to use this. 19. WHERE CAN I GET MORE INFO? A good place for General GPS info, NMEA info, and shareware: ftp://sundae.triumf.ca/pub/peter/index.html Rockwell Semiconductor Division information is available at: http://www.nb.rockwell.com Publications (Rockwell): Zodiac GPS Receiver Family Designer's Guide (Order No. GPS-27) This is available through the Rockwell literature line at 1-800-854-8099 or via email sent to literature@nb.rockwell.com. Zodiac Software Data Interface I/O Specification (Order No. GPS-25) I am having trouble getting this one. This explains all the NMEA and Rockwell commands the Zodiac chipset understands. Also, check out the newsgroup sci.geo.satellite-nav. It currently has discussions on SA 4.0 and Tripmate. 73 and have fun de WB1HBU Eric A. Cottrell eac@shore.net