TripMate/Earthmate II/Delorme Tips, Tricks and Pinouts

© Beverly Howard, Austin, Tx, 2002 - 2007
Content may be "linked" with permission but not reposted
Tripmate Mounted on Stoplight of Pickup

Additional GPS Links to;
Bev's GPS Theory Tutorial
GPS General
Magellan's Meridian
Magellan's Explorist
Raw Map Reduction
Turn by Turn Routing using Google Maps

First, as far as Delorme is concerned, the Tripmate no longer exists... a search on their site for the word "Tripmate" turns up no results.  But there are still a huge number of these units out in the world, and if you can find one for cheap, grab it, as, in my experience, it is a good, accurate NMEA compatible GPS receiver which can be a very inexpensive way to start learning about the GPS system using Delorme GPS mapping software.

However, the unit is dated, designed to be used with Delorme products (see below for the special "init string) so I have moved on to more uptodate products such as the Magellan Meridian and Explorist self contained handheld mapping units and have forgotten most of what I used to know about the Tripmate, so, if the information you seek is not on this page, it's "Google Time" as asking me is not going to be productive.

Enjoy it and may you learn as much as I did.

Tripmate Drivers?

As time passes and the Tripmates quietly age around the country and globe, many find their way to EBay to be bought without any documentation by the curious.  As a result of that and this being one of the few Tripmate information sites, I am getting an increasing number of queries, many of which are "Where are the Tripmate drivers?" along with "What GPS software will it work with"

First, it is a serial device (4800,8,n,1 with no flow control) so it does not require drivers to work, just a program that communicates across a RS-232 serial connection.   If your computer does not have a serial port, you can use a usb serial "dongle" and, while the "dongle" will require usb drivers, serial devices such as the Tripmate do not.

"ASTRAL" Initialization String

However, unlike almost all other serial GPS receivers, it will not begin receiving until the string "ASTRAL" (see below) is sent to it via that serial connection.

While the Tripmate is NMEA compatible (the geodetic datum used is WGS84,) when using it with software other than Delorme, the software must first transmit the string ASTRAL <crlf> to trigger it into action.  If this is not done, the Tripmate will simply transmit the same string until it's batteries die.

Next, the Tripmate was designed by Delorme so that it should work with any Delorme software that has GPS options such as Street Atlas.  A few other GPS/Map programs support the Tripmate, and if they do, "Delorme" and/or "Tripmate" will be selectable in the software's GPS setup.  If "Delorme or Tripmate" is not an option, the Tripmate will not function as it will not be initialized by the software.

MS Streets and Trips does not support the Tripmate.

I have been able to initialize it for some PC programs by starting a terminal program such as Hyperterminal and sending the "ASTRAL" string, but this will not work with XP or the PocketPC OS since those operating systems do not allow two different programs to access the same serial port at the same time, plus the port is "closed" when one program releases it which puts the Tripmate back to sleep.

Since the Tripmate itself puts out the "ASTRAL" string repeatedly when it is inactive, another solution has been to rewire the serial connector so that this string is routed back to the receiver to wake it up.
show wiring options to meet this need.

Delorme GPS Initialization Fix
for Street Atlas 5 & 6 + Topo 4

Delorme has finally acknowledged that there was a Y2K issue in the Tripmate GPS's initialization portion of it's Street Atlas applications and has provided a fix!  Getting this patch will be necessary to run early versions of Delorme GPS compliant software.

This also dispells those rumors that the TripMate hardware unit itself was not Y2K compliant.  The interface is prettier and includes a compass... I wish they had provided a "click current location" rather than having to re-enter lat/long after the Tripmate makes a long jump packed in airline luggage.

The page offering the fix (long gone)was off of the "other" software tab and provided a list of the fixes that included a "Year 2000" item that fries me a bit after a series of tech support calls to them clearly id'ing this issue as being in their app but receiving only rebuffs from them.  AllGPSUpdate.exe is the actual patch, it's about a meg so it's easily accessable via a modem connection.

Without the update, the one thing that worked was to;

1 - Start Street Atlas (mine was version 5.0)

2 - Initialize the GPS with your current location

3 - Exit Street Atlas completely.

4 - Restart Street Atlas and do not initialize or check "start tracking"  but start GPS/MonitorGPS and go to the satellites page.

The initialization will take longer than it should but, after it finds it's first satellite, it seems to be able to correct the incorrect date that was passed with the bad init then continues with the location data to a 3D fix... you will hit the "timeout" but simply continue... don't re-initialize.

Delorme's Earthmate II

Delorme has (imho) pretty much lost it's edge as a gpr receiver provider as there are a wealth of NMEA compatible receivers now available but the others all have the limit of providing only a single communication option, so, you have a purchase decision choose between Serial, USB or BlueTooth where the (now discontinued) Earthmate II provides the potential for all three.

When the EarthMate II was finally closed out I picked one up from Frys which included the "Bluetooth Backpack" based on it's original claim to serial options, but when I opened the package, found that the only serial option that Delorme offered was to run a serial emulator on the pc to convert usb input to serial for older software, something that's not an option with a PocketPC or laptop without USB and a call to Delorme confirmed this serious limitation (which I have found since to be incorrect.)

The following pinout information took over a year to uncover... at forums in a post by "asci01" who left no contact information but deserves the credit for providing the following pinouts via the above thread.

Earthmate II
Pin Outs

1 - GND
2 - USB Data+
3 - USB Data-
4 - +5V

5 - RS232 RXD
6 - RS232 TXD
7 - RS232 DTR
8 - +5v
9 - GND
10- nc
11- nc

NMEA 4800/8/n/1
DTR high pwr on
DTR low pwr off

2 RxD
3 TxD
5 SG
9 RI

Serial Cable



The Earthmate II (Delorme receiver model# 9538) connector is pretty non standard so I had finally assumed that getting another ($40) usb cable from delorme to kludge a serial connection was the only option to tap the serial connection, but, with thanks and a tip of the hat to Brent Buch who found the connector, (part SC01) at Pc-mobile, it's not only possible but easy to build a serial/power cable for under $10 which allows this GPS receiver to be used with serial (many pocketpc's, older laptops) and USB plus it's bluetooth backpack... as far as I know, a multi interface option not possible with any other GPS receiver.

In addition to the serial option the above connectors are so inexpensive, it's now cheap to "hardwire" a GPS to computer connection in vehicles which allows the receiver to be easily moved from one to the other as needed.

FWIW, the name "Earthmate" began life with the taint of a bad reputation as the first Earthmate did not use the NMEA protocol but rather the Rockwall binary protocol, so, it was incompatible with almost any non Delorme mapping software to the dismay of many who bought one.  Fortunately, the II uses NMEA 2 protocol, provides WAAS augmentation and uses the SiRF/LP chip set.

Several tricks that make the Tripmate unit more valuable.

Building a (small) 5v Power Tap

The first is the capability to power the unit via the serial cable.  Delorme's price for the cabling to allow this is actually very reasonable as they include both a PS/2 keyboard/mouse laptop pass through tap and a 12v->5v cigarette lighter converter for $39 at

However, the amount of cable that comes with this kit is overwhelming and I created my own minimalist serial feeder for the Tripmate using a pair of DB9 connectors and a short piece of "mouse tail" from a dead ps/2 mouse.

The following was executed on my unit and tested, but, as always, you MUST accept responsibility for any damage to your computer, Tripmate or any think else resulting from using and executing the following information.

To create your own adapter, get a matching pair (one male, one female) of DB-9 connectors and remove pin 9 from the female connector.   Place the connectors back to back and solder the wire connectors for pins 1-8 (skip pin 5) together.  If you haunt electronic supply houses, find one of these connectors with pins designed to fit into a pc board rather than wire cups on the back and they will fit together perfectly to join with solder.

If you are really a serious minimalist as I am, take a pair of strong scissors or metal shears and cut the anchor holes off of the metal DB-9 housing.  The rest of the housing can then be removed and the two plastic pin holder halves separated enough to fill with a bit of glue and rejoined.

Using a PS/2 connector pigtail (scavenge one from a dead PS/2 mouse) locate the wires for pins 3 and 4 (see below) and then isolate and insulate the remaining wires.

Connect the wire from pin 3 (ground) on the PS/2 connector to the pin 5 pass through joint on the DB-9's

Connect the wire from pin 4 on the PS/2 connector to the male pin at position 9 of the DB-9 pair you just created. Remember!  There should be no pin 9 on the female side of this connector bridge!

Running a hot glue gun all of the way around the join of the two connectors is then the best way to insulate the soldered connections, but it is important that they be insulated. On an early trip, an uninsulated moment in a rent car in a location that I could have really used location information, my priorities quickly shifted to finding a Radio Shack and a fuse as fast as possible.  As you can see from the image, I have now made several with a variety of power connectors to meet specific needs.

The following is the view into the male pin side of the mini din connector and the "|" indicates the position of the PS/2 connector "key"

  - 3   4 +5v
     1 2

To switch the Tripmate from it's internal batteries to an external power supply, all that is necessary is to disconnect the internal battery cable and use a short standard jumper block and bridge the two pins in the battery connector that are closest to the center of the unit.  This can be done with any standard "jumper pin" that is used in many computer configurations, but if you want to mount only the top half to something, the short version of these jumpers are necessary to assure that a good weather seal is made to the metal.

My current laptop (A Sony PCG-C1X Vaio) does not have a PS/2 port, so I have been using an external 12v-5v adapter ($12 from Rat Shack) but it's possible to create a 5v source by modifying a short USB cable and adding a tap to the USB power pins.

The Tripmate is housed in a two piece plastic case with the electronics and antenna in one half and a holder for 4 AA batteries in the other.  The electronic half has a weatherproof seal that allows you to completely remove the battery half and with two (8-32?) machine screws it's a snap to mount it to any relatively flat surface retaining the weatherproof benefit of the existing seal.  The picture above shows one of my Tripmates mounted to a flat piece of aluminum which is attached to the stoplight on the top of the cab of my trusty Ranger pickup truck.

The following information was recovered, with great difficulty, after the original link and page disappeared from the web, so I can't give credit for it as I would wish.  If you know the source, please email me so that I can post the credit or switch to a valid link.

Proprietary commands for the Tripmate

A less than comprehensive list of commands and what they do.

Startup Command:    ASTRAL Without this command, all the TripMate does is send ASTRAL over and over again. It needs to see this sent to it with at least a cr  or crlf. All of the other commands require a crlf  after them.
Initialization Command:    PRWIINIT The PRWIINIT command is used to reset or preset the Tripmate. 
$PRWIINIT,A,,,,,,,,,,,,, crlf This command resets the TripMate to power-up configuration. It then requires the ASTRAL command to re-enable the system.
$PRWIINIT,V,,,latitude,N/S,longitude, E/W,0,0,M,0,T,time,date crlf This command when filled with the correct data will preset the TripMate with the time, date, and location. Using these values will allow a faster "time to first fix".
PRWIINIT,V,,,4828.00,N,8312.00, W,0,0,M,0,T,145147,230798 crlf This is a sample of the command. I don't know what all the parameters are. There is likely a form of this command that stores the values internally into the TripMate, but I haven't figured it out yet. I have had a few different values saved, but I haven't determined what makes it do that. What is also interesting is that the Street Atlas program sends this command incorrectly. But I'm not going to tell them that.
Output Control Command:    PRWIILOG The PRWIILOG command controls what sentences the TripMate sends back to the computer. My viewer program only uses the RMC command so I turn the rest of them off.
$PRWIILOG,RMC,A,T,1,0 crlf This command sets the TripMate to send the GPRMC sentence one per second. This is the default for this sentence. The number can be replaced with a desired number. I have tested it with 360 so I know it goes over 256. I haven't tested the maximum limit though. If you need a number that high, you might as well use the next commands to turn it off and on only when desired.
$PRWIILOG,ZCH,V,,, crlf This command sets the TripMate so that it doesn't send the PRWIZCH sentence. Seeing as I don't know what information this sentence provides, it seems like a good thing to send to reduce the amount of data sent.
$PRWIILOG,ZCH,A,,, crlf This command is the reverse of the above. It turns on the sentence with whatever time interval was previously set.
Note: The above settings are stored internally by the TripMate so if you turn something off, it will stay that way until it's turned back on.
Self Test Command:   PRWIIBIT I have no idea how this works or what it does.
Last Revised 5 Aug 1998

Roof Top Mounts

This may sound stupid, but other people out there tend to get really flipped out when you put something bright yellow on the top of your vehicle and then drive around with it up there.  They are trying to be helpful, but their concern and attempts to notify me of my mistake of leaving something on the roof when I used a magnetic mount on Tripmate and simply stuck it on the roof lead to some seriousnear misses with multiple vehicles from these good people frantically attempting to notify me of my mistake.

Window Mount

To deal with this, my "rent car" Tripmate is now mounted to a flat piece of thin metal that is bent to fit over the top of a window which can then be closed and holds the antenna at roof level.  This more permanent appearing mount apparently removes the assumption that I've already gone senile.
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