Palm OS Hardware for Navigation

By: Dale DePriest

palmnavThis page supplements my main palm page with hardware specific information on gps and other navigation hardware support for the palm platform. Generally any gps that can be used with a laptop can also be used with Palm. This page covers the information needed to get this hardware connected. There are several sections on this page including:

Palm Units

There are now at many sources of palm OS units. The original source from 3 com, the palm, a unit from IBM called the WorkPad which is just a repackaged palm with identical specifications, and new units with different hardware implementations licensing the palm OS software. These include the HandEra (formerly TrgPro) and Hand Spring Visor. HandEra offers a standard compact flash expansion port while the Visor has its own unique hardware expansion solution. The newest unit is the Sony CLIE. It features a memory stick addon memory module. It has a USB interface but includes serial support on most models. In addition there are some specialized products from other manufacturers that use the palm os and could probably be used with gps receivers. Newer players in the palm arena include Garmin with a Palm unit that includes a GPS and that has just released the Zodiac unit. Several cellphones now include the Palm OS.

Palm make many different hardware configurations. Electrically these different configurations are interchangeable but physically there are differences. The III and its successors is the minimum system that should be considered for mapping use due to memory considerations. Earlier units do not have enough memory or gray scale support. The V series uses a different connector interface from the III series but this should not pose a problem. In addition mechanical size differences may prevent some solutions. For example the new IIIc unit is slightly longer than the older units which prevents some hardware from snapping on to it. Palm, WorkPad, and HandEra all have electrically similar serial ports and should work with any serial device. The VII uses the same serial connector as the III so solutions that work with the III should also work with the VII. The latest palm offerings can also be used with a serial port gps receiver. The palm 500 and palm 505 can be hooked up to a GPS using serial hotsync cables and gps serial cables hooked with a null modem/gender changer as described below. These devices use the newer Palm Universal Connector which has USB and Serial capability.

Problematic Palms

The new Tungsten E and the Sony Clie J35 do not have a serial port at all so these units will not work with most standard gps devices. There is now a solution for Tungsten E from Kirrio and Palm one. This solution will also work with Zire units.

Others have incomplete or unusual implementations and are covered in the section below about usb devices or look below for other solutions.

Dedicated Palm / GPS

An exciting new development is a GPS that runs Palm OS. Garmin has released a product called the iQue 3600 that is a full gps and a palm all in one case. It matches the functionality of a Garmin top of the line GPS unit with all of the functionality of a Palm running OS 5. In addition there is integration between the two functions such that the gps can use the standard palm address book as a source of destinations. An mp3 player and voice response is also built into the unit. This unit will not run standard Palm GPS software unless it has been modified to work with the Garmin GPS specifically. There is a review of this unit available.

GPS Hardware

Any gps with a serial port can be hooked to a palm. In addition there are Hardware Specific gps solutions available. For a standard gps units all you really need is some software and an appropriate cable.

The primary hardware connection on a palm is the hotsync serial port. Using adapters and cables that are described below you can hook up any gps with a serial port capability directly to the palm. (The HandEra uses a palm III compatible port as well.) In this way you can extend the capabilities of a standalone gps unit by providing a connection to the palm's processor, display, and memory capabilities. All Garmin handheld units have external data port capability and can be hooked to a palm. Most Magellan units also have a data port capability and can be hooked to a palm. Note that Magellan does not output data until a fix is achieved or placed in simulation mode. In addition units with serial ports from Lowrance, Trimble and other gps manufactures should have no trouble hooking to the palm. All of these units understand an industry standard NMEA protocol so that programs that use this protocol can get real time data from any of these units. In addition to NMEA most units also support a proprietary interface to provide extensions to the NMEA capability. To support upload/download of waypoints, routes, tracklogs, etc. you will need to use a program that understands the specific gps device you are using.

Dedicated laptop devices

There are also gps devices that are intended to hook to laptops because they have no storage or display capabilities. Many of these devices can also be hooked to a palm unit. Most use a standard serial port so can be used just like the standalone units mentioned in the previous section. The Rand McNally unit, some units from Garmin, a new unit from Trimble (requires a custom turn on message), and several others fall into this category. You may need to figure out how to supply external power to these units as you cannot get power from the palm itself. The Rand McNally units does have an external 12 volt adapter available from their web site support area and some of the others support internal batteries. Another unit is from Holux that features the same engine as their dedicated unit described below. In addition many of the manufactures listed in the dedicated units section below often also make mouse like units.

Delorme Products

Delorme makes three units that can hook to a serial port. The Delorme products are similar to other laptop devices except that they do not speak standard NMEA (except for the latest version) and are intended for use with Delorme software only. But, because of their popularity there are some other software products that can work with them. The older product called a "Tripmate" does use a mostly standard NMEA but requires a special initialization sequence to start it running. The newer "Earthmate" unit uses a Rockwell binary format. Check with the software maker you are interested in to see if they support the Tripmate or the Earthmate before attempting to use these products with the Palm. There is also a hardware solution, GST-1, available from Byonics. It offers translation from Rockwell binary format used on the Earthmate and the Sony Skymap receiver to standard NMEA protocol allowing these receivers to be used with Palm programs that don't directly support the Rockwell format. Note that they also have a translator, GST-2, available for the Aisin GPS for those that want to build their own gps.

Earthmate also requires the DTR signal so be sure this signal is in any cable you build. One way to provide this is to build a male to male gender changer that wires 2/3 and 3/2. Also wire 6/4 and 4/6 to handle the DTR signal. You only need 4/6 one way but having it both ways means you can't plug the adapter in backwards. Note the DTR from the palm will keep the earthmate receiver on all the time it is hooked up. You should unplug it when not in use to save batteries.

Delorme has announced a new gps that has a USB interface with a serial adapter on the way. It uses the SiRF chipset so it does have NMEA support and WAAS capability.


Deluo Electronics has entered the palm market with a universal mouse style product. They have specific cable available for serial ports, Palm V, Palm m130/m500, and Handspring Treo/Visor/Edge. There is a review of this product.

Mr. Jiulong Zhao has a mouse like gps specifically designed for Sony and palm units. Here is a display of his products. It is in chinese but the pictures are universal. He has indicated that the units are under US$90. He has 4 models: GPS-A (for Sony T / SL / SJ / NR /NX/DG ), GPS-B (for Sony N / S ), GPS-D (for Palm M500 / M505 / M515 / M130 / TT / TW), and GPS-E (for palm V / Vx / IBM C3 / M100 / M105 / palm III)

Mapopolis has announced a unit specifically designed to attach to a treo as well as units for Tungsten, other palm devices, and Sony devices.

Serial Port Cable Information

For commercial solutions see below. This section covers general information for users want to build their own cables or adapt existing cables. If you want to adapt a palm gps to other devices or remote mount it check the section on mounting below.

Palm Units with regular Serial Ports

No matter which solution is used you will probably need a cable to connect up the two units. You can fabricate your own using a cable with the appropriate GPS connector on one end and wired using this information or if you prefer you can try one of the solutions described in some of the links below. Folks owning Magellan 315 units may find this drawing helpful. Many folks have used the hotsync or modem cables coupled to existing gps interface cables with null modem and gender changer adapters as needed.

If you are building your own cables you will need some connectors. Some folks have been known to make their own connectors as well but generally it is easier just to buy them. A few sources for Garmin gps connectors include and A source for connectors at the Palm/Sony end is Another discussion for Sony conneciton is available from

Delorme makes a cable for PalmPilot use. I bought one from CompUSA. It claims to be only for their earthmate product but it will work with any gps unit by plugging it into the standard 9-pin connector that is part of the vendor supplied computer connection cable. It automatically handles the null modem pin swapping for you.

Another solution is to get a pilot hotsync cable and a standard computer interface cable for your gps. Then obtain a male to male gender changer connector to hook them together. (Fry's has these.) If you can't get a male to male gender changer in one unit then you buy a male to male connector and add a gender changer adapter but the overall link of cables and adapters starts to get a bit messy at this point. You can make your own male to male gender changer by obtaining two male 9 pin connectors. Then you would wire pin 2 to pin 3, pin 3 to pin 2 and pin 5 (gnd) to pin 5.

Handera units have exactly the same connector as Palm III units so any cable solution for Palm will work on a HandEra unit.

Palm V users can get the travel kit and use the cable supplied along with a null-modem cable as described above to make a connection. Some third party cable folks listed above have custom cables for the Palm V as well.

USB discussion

The handspring, the Sony CLIE, and the new Palm M500 series units feature a USB hotsync. Standard gps devices cannot be used directly with these units via USB. Sony and Palm USB units also have a built in serial port in the connector. Handspring does have a serial sync adapter that some have adapted to hook to a gps. Unfortunately the adapter taps power from the serial port on the pc and cannot be used directly with the visor. You would need to design your own power supply or battery connection to make this work.

Handspring modification - I have not tried the following steps myself and cannot guarantee they will work. This may void your warranty so proceed at your own risk. You need a source of power from about 5 Volts to 12 volts. (There is a isolation diode and a 3.9 volt zener in the cradle.) You need to include a series resistor of at least 120 ohms and perhaps as high as 390 depending on the source voltage to limit the current. One choice is to just use a 9V battery. Whatever your choice you need to wire the negative lead to pin 5 of the DE9 connector and positive through the series resistor to pin 7, the RTS line. Of course you still need data, 3 to 2 and 2 to 3, and a data ground also on pin 5. This information is from Curtis Mills. He made a 9 pin to 9pin adapter cable for his unit, combining gender changes, null modem, and power source. He taped a 9V battery to the cable. Thanks for the information, Curtis. Check the discussion of this topic on PocketAprs.

The serial data itself is directly available from the HandSpring unit. It is not the correct polarity and only has a 3V swing but some have had success wiring it directly to gps units. A source of data is Handspring Visor Page. This solution has inverter hardware but does not need the serial cradle. Also check here for more information on this topic. Click on any of the .txt files to get started.

You might also check ATL, however they have a minimum price so it would be good to form a pool of buyers.

Most models of the Sony CLIE use a USB interface similar to the HandSpring but also contain a fully functional serial port as part of the unit. For information on making a cable for the serial port check this site. Remember that the site is describing a serial hotlink cable. For gps use you will either need a null modem adapter or rewire it to swap RxD and TxD. If for some reason the site is down, the essential details are:

Device connector to 9-DB wiring 
4 <-- RxD 3 Txd
5 --> RTS 8 CTS 
6 --> TxD 2 RxD 
7 <-- CTS 7 RTS 
12 <- CNT 47K ohm resistor tied to pin 13 (GND) 
13 -- GND 5 GND 

Note that the resistor is what tells the CLIE to use the serial port rather than the default USB port. Note that the new T-series units only output 3 volts on their serial port and some gps units need more than this so a hardware solution instead of just a simple cable may be needed.

The latest Sony units seem to have removed full rs232 compatibility but there is still a way to hook a serial device. For more information on the Sony Clie T415, T615C, T665C, NR70, NR70V, NX70, NX70V, SL10, SJ20, SJ30 handheld computers that have 18 pin HotSync connector please check GPS2Clie for an article on making your own cable. Another discussion is at Dan Anderson's site. He has information on Sony units and it is generally a good discussion of RS232 issues. Some commercial solutions are available for these units also.

The Palm M5XX units and Tungten models with the Univeral Palm connector also have a USB port, but, like the Sony, they have a fully functional serial port as well so, with the correct cable, connecting them to a gps should not be a problem. The serial hotsync cable can be used with a null modem adapter, for example, and any of the solutions described in the serial cable section. If you wish to wire it up yourself here is the essential details.

Pin#  Signal Name. Function
 1     GND         Connection to pin 7, signal ground and charging ground
 8     ID          Peripheral ID: a peripheral must tie this to appropriate 
                   1% value resistor connected to ground.
                   USB Cradle             : Short
                   RS-232 cradle          : 7.5 K ohm.
                   Mfg Test cradle        : 20 K ohm.
                   USB peripheral         : 47 K ohm.
                   RS-232 peripheral      : 100 K ohm. (use this one)
                   Modem                  : 220 k ohm.
                   Undocked               : open (>10,000 K ohm.)
 10    RXD (in)    Receive Data from GPS
 11    TXD (out)   Write Data to GPS
 12    DETECT      must be tied to ground by cable.
 14    RTS
 15    DTR

Palm users with the new Palm Universal Cradle may wish to modify this cradle to provide both USB and serial port access. Here is a site that provides the details on this modification. You can use this modified cradle to sync your palm and download waypoint data from your palm using GPilotS directly to the pc via the serial port or for other uses.

Commercial Solutions

There is an increasing need for commercial solutions to the cable interconnect problem. As new units are released many folks are unable to create all of the cables for themselves or would prefer to just buy a custom solution. To meet these needs there are now many companies that have cables to interface a gps to a palm. I have tried to collect a list of them with a brief description of their products in the table below. Be aware that these companies are constantly coming out with new products so just because I don't mention support for a particular palm unit doesn't mean that they do not produce a solution. The focus of this list is on single cable interface solutions but many of these companies also offer generic interface cables and external power solutions as well, either for the gps or for the palm or both. I have a separate section in this document that covers issues of external power.

  • The Supply Net
  • Cables including small pigtail adapter cables. They also have dongles for pcmcia adapters if you lose yours.
  • Pfranc has moved beyond just having connectors. They can also supply full cables these days. Note that Pfranc isn't just one company, they are a franchise with lots of companies in many countries. Most are individuals working out of their garage and many can supply custom solutions.
  • Blue Hills Innovations
  • Cables for most units.
  • GPS City
  • Palm cables and adapters.
  • Boston West Group.
  • They call themselves "Ugly Cables"
    A German Source
  • They have Garmin adapters and support for the M500 series and Sony. The site is in German but the the author knows English quite well so if you cannot figure out what you want just send an email.
  • Mark/Space
  • A new cable being offered that addresses the need to translate signals on Visor serial data. It has a hardware solution in the cable but does not work with the platinum. They have cables for most palm hardware models from all vendors.
  • Hubclub
  • for England but they will ship overseas. They have Garmin specific versions.
  • Purple Data Cables
  • for many palm models including Clie and Visor as well as 3Com. M100 is covered.
  • Pharos
  • cables for palm (including the M500/505) and Visor. Follow the retail links on their site to buy them.
  • PC
  • Cables for Garmin and Magellan and all palm OS units including Sony, Palm, HandSpring, HandEra, etc. They have hard to find cables for some of the Sony units.
  • Delorme
  • has a cable specifically to tie their earthmate unit to a Visor, Palm, and other units. It will work for other serial devices as well. It is not a one cable solution but rather a pigtail that adapts the pc cable of the gps to the palm.
  • A Hong Kong shop with lots of standard palm / sony / handspring cables. No gps specific cables.
  • Custom cables for various gps to palmos devices. Features Garmin and Magellan specific interface cables. Will ship overseas from Australia.

    Other interfaces

    SDIO GPS devices are just around the corner. Check iGolfGPS for example.

    Some gps devices use the pc-card (pcmcia) interface to laptops. There is a pc-card interface available for the palm device. It is not known whether there is any software gps support for this interface but gps devices are listed on the parachutetech web site. They also list support for CF devices so it is likely that it supports Compact Flash GPS units as well. Another pc-card sled is called Guyver. It contains its own battery. It is available for several Palm OS devices.

    You might look over the Mobit Crux unit as a source gps device that may work. You could also use V.DOT CardHost Pro to interface any serial pcmcia device though the serial port on your palm.

    Bluetooth GPS devices will generally work on any Palm that supports Bluetooth capability. Note that two steps are required. First you must pair the Bluetooth GPS to the PDA and secondly you must select the Bluetooth GPS in whatever GPS capable program you are using. Generally programs default to the serial port connection and must be specifically written to support Bluetooth devices. Most GPS programs do support Bluetooth on PDA's with Bluetooth support. This may be the best or perhaps the only method of hooking a GPS to some PDA's. You can get a gps from Linkspoint that will work. Or check Emtac Crux for their bluetooth model. Also check out US GlobalSat. There are many other BlueTooth units these days.

    Other specialized palm units have clipon sleds that attach to the back of the unit and connect via the serial connector. These GPS units are covered below in the Hardware Specific Solutions.

    All palm devices have an iR port so this solution may offer some possibilites.

    Hardware Specific Solutions

    In addition to the generalized gps receivers and other navigation hardware that can be connected to a palm via a cable there have arisen several navigation devices that are specifically designed to be used with Palm devices. This section covers these devices.

    Palm devices have different mechanical and physical dimensions that may prevent a particular hardware solution from working. For example the palm III and the palm V use incompatible serial port connectors. In the table below I have attempted to best guess the compatibility of the various palm models. Do not trust this table without checking for yourself. Please let me know of any errors and need additions or corrections. Some of these devices may not be shipping yet. Note that a vendor may have several models with specific interface capabilities. Seeing that a vendors product is available for multiple platforms does not mean the same physical hardware can be used on all of those platforms.

    Description Palm
  • Palm Navigator A hardware compass with map support. This is an electronic compass that plugs into the bottom of the palm pilot.
  • Rand McNally makes three hardware gps configurations specifically designed for palm pilots. One is for the Palm III, a second one for the Palm V, and the latest unit for the Palm IIIc and Palm VII. The engine for the palm III version uses the Rockwell chip set while the engine for the Palm V is made by Magellan (see below). The Rockwell unit is very similar to the serial unit mention above by Rand McNally and is an oem product from Navman except that it has the clock, and a few other hardware features removed. Each unit clips directly onto the palm, no cable needed. They have recently delivered a third unit. It fits palm IIIc and palm VII units. Note that folks have also adapted their notebook model.
  • IGPS is a unit that supports Palm III and V connectors with included cables. It is a small remote unit that cables to the palm so it should work with any unit will compatible connectors. They also offer a model with 9-pin D connector that should make it adaptable to any computer with an appropriate adapter.
  • Magellan GPS Companion has taken the unit originally designed for Rand McNally and is marketing it directly through its normal distribution channels. It is called a "GPS Companion" and comes with two software packages. Nav Companion is a unique Magellan product while Map Companion is a slightly modified version of the MarcoSoft Quo Vadis package. Both software products are covered on the software page and there is a full review of this product. Magellan is also delivering a similar product for the handspring and a review is available. Note that the firmware in these products are different from the product sold by Rand McNally.
  • HandyGPS A gps device based on the SiRF chipset that is specifically designed to work with the Hand Spring unit. Handy GPS has two software packages available for their gps. A basic package comes with the unit and a mapping program for the US is available for download to registered users. The hardware is not compatible with other software packages.
  • CompactGPS is a gps in a compact flash format from Pretec. Uses the SiRF chipset.
  • Fortuna Electronic They have SiRF based gps units packaged as CF, PCMCIA, Mouse type, and standalone. The CF unit features the ability to support an external antenna. There is a review available for this product when installed in a pocketpc.
  • Transplant Computing provides another gps in compact flash form.
  • Crux II is a new CF gps receiver from emtac. They also make a pcmcia version. TDC is a dealer in England that carries this while Mobit is dealer for this product in Italy. The description is in Italian but you can look at the pcmcia version that has a description in english or use a web translator. It uses the SiRF chipset and supports an external antenna. The pcmcia version might also be useful on other palm units with some of the adapters described above.
  • Geo Discovery is a new handspring GPS module with maps and other geocode data. Supports WAAS and includes a digital compass and two 64 Meg memory expansion slots for maps and data. Here is a picture.
  • Talon Technology is an New Zealand company that provides the hardware for many products for gps palm use. These include some of the Rand McNally units above as well as products available as the German Navigator and the hardware for the US fastcomute product. Many other sources are also available.
  • NavMan is a clipon gps receiver for the III and V. A second model is for the Palm M series products. It includes a car mount a car power adapter and mapping software called SmartPath city and Smartpath Trip. It has a built in rechargeable battery on the V version but uses the Palm battery on the M version. Note that the NMEA mode on this unit is at 57600 baud so, unless the software program specifically permits setting the baud rate, 3rd party programs will not work with this unit. For europe try NavMan Europe
  • SkyGolfGPS has a specialized Golf computer utilizing a modified Magellan GPS to provide location data. It provides maps of golf courses with precise distance to hole information. The gps hardware should be useful with some other gps applications.
  • Holux now makes some palm addons that complement their line of standalone units. The 250 series has its own batteries, provides for an external antenna and external power. Has standard NMEA output and uses the SiRF chipset.
  • Sony clie has a unique expansion slot that uses a memory stick. They have released CF adapters and GPS units in Japan for these units. The CF adapter is likely to permit CF gps units to work in CLIE devices. Check the for a Memory Stick GPS.
  • Linkspoint
    GlobalPoint GPS is the name of several new hardware gps units including a compact flash receiver, a bluetooth gps, and an add on attachment for symbol PDA's
  • Deluo Electronics has entered the palm/os market with two offerings. A CF receiver and a universal mouse style product with specific palm interface adapters.

    * The HandEra 330 is totally compatible with the Palm III electrically and physically. The HandEra TrgPro unit is a little larger than the Palm III but folks have indicated that a Rand McNally Palm III unit can be made to work using a dremel tool or file to remove some of the plastic from the gps.

    One guy has even adapted the Rand McNally Palm III unit to a Palm Pro. He cut two small 'nubs' off the bottom of the case and it worked fine. He also added a strip of velcro to hold it on better since the Palm Pro is a bit wider than the Palm III.

    ** Palm M series includes the M500, the M505, and the M125 with the new universal serial port connection.

    Troubleshooting Hardware Problems

    The first thing to do if you have problems with your gps connection is to suspect the cable connection. Often there are several cables and adapters in use and a poor connection is always a possibility. In particular the palm connector can easily come loose and make a poor connection even when it seems to still be hooked up. Unfortunately this connection is not a particularly positive one. You could fabricate a velcro connection or obtain or fabricate a connection clamp. Let me know if you come up with a neat solution to this and I will include it here.

    Mounting and Powering your Palm

    While mounting your palm in a vehicle is not unique to gps usage the new Unimount system provides some essential features to solve some of the palm's major problems when using it for navigation. Not only do they offer a good mounting system but also provide for externally powering the palm unit. Using a serial port full time on a palm can significantly shorten the battery life so the ability to power a unit externally or with rechargeable batteries can be very important. Another suite of simple mounting solutions is available from The Clip

    If this mount is too expensive for your taste you may want to check Magellan for their mount. It has a special notch in it to allow it to work with the gps_companion for visor. There are other sources as well. Another source of mounts for palm is (Look for car mounts.)

    For mounts that solve a multitude of problems you might consider a powered PDA mount with a built-in speaker, it can also serve to charge your Palm as well as amplifing the volume for GPS programs with voice output. Arkon and Seidio make almost exactly the same mounts and you can choose from 3 different mounting styles - suction cup arm, doublesided stickey-tape dashboard mount, or vent mount. Also chheck Proclip for custom vehicle solutions.

    Remote Mounting of the attached GPS units can be a bit more of a problem. Several folks have encountered situations where they want to use a attached device either mounted in a better receiving position, have a need to shield the screen display, or perhaps they wish to attach it to a computer that it wasn't designed for such as a laptop or perhaps a different model of palm. There is at least one commercial solution for this problem from Mark/Space for the Palm V. I also have reports of folks that have successfully interfaced the palm III version from Rand McNally to the serial port connection on their laptop. Once you have adapted it to a 9-pin D-connector it is fairly easy to find adapters to the unit of your choice. Here is the documentation for the palm III connection:

    Palm connection              Serial Port Connection
    3-RxD                                  2-RxD
    4-RTS  (CS to keep GPS on/active)      7-RTS
    5-TxD                                  3-TxD
    10-Gnd                                 5-Gnd

    The GPS Companion for the Palm V clips on the back of the unit and, again, some folks would like to remote mount it so get better reception in a car or adapt it to other computers. Either use the mark/space solution or make your own. Here is the data needed when adapting to a hotsync cable:

    Palm    DE9
    1(DTR)	6(DSR)
    3(RXD)	3(TXD)
    5(TXD)	2(RXD)
    10(SG)	5(GND)	

    Remote Power of the palm itself is a growing concern to users of GPS devices. The Unimount system described above has a growing list of Palm units that can be remotely powered as part of the mount. Check with for several solutions of power that will run both the palm and the attached GPS. The site is in German but an email with your requirements will get a custom response in English.

    If you own the Palm V version of Magellan GPS Companion or Rand McNally Steetfinder GPS supporting the Palm V or the one that supports the IIIc/VII you may be interested in powering your Palm from the external gps power plug. A modification to your gps is available from skydragon. Hubclub is working on a solution for M500 units.

    Here is a rechargeable battery pack for a palm from Belkin. Another rechargeable retrofit for Palm units and soon for Visor units comes from Pellico Systems. And yet another is available for Palms and Visors from (Look for Travel and Navigation hardware and take a look at their car mounts). Or if you just want to use rechargeable batteries with a traditional charger then you might want to look at Thomas Distributing. Be sure that you get at least 700mAH batteries, and replace or recharge them as soon as the low warning indicator says or to be safe even sooner. A good charger is the PS-4 from Rayovac. It is a one hour charger that treats each cell individually. They also have batteries of course.

    There is also a problem if your unit already uses rechargeable batteries but you are no where near a charger. For Visor products, Visor Solutions" has a small battery case called battplug that can be used to recharge the internal battery. LandWare has a product for Palm V as does Tech Center Labs. They also have emergency charger for Treo and Tungsten T and M series Palm units with the universal connector. For M series products and the new Tungsten you might want to try the vehicle solution from The SupplyNet. They have a Y cable that powers both the Palm and an external gps from a car accessory outlet while also providing an interface data solution. I have a review of this product. Another source for battery cases for lots of PDA's is wholesale-pda-accessories. Also check with PC for car solutions and battery boxes for recharging internal batteries. A fairly expensive but universal solution is from Laptopsforless. This uses lightweight rechargeable battery modules.

    Perhaps you need to charge your unit and you are on a week long hike. The solution may be a solar charger from Silicon Solar.

    Protecting your palm

    One really important consideration if you intend to use you palm for navigation is protection. Palm units are not waterproof and are not particularly shock resistant. The screen is glass so it needs even more protection. There are some units that are more rugged than others, for example Symbol Technologies is known for making rugged units. However for most folks some sort of protective covering may be useful.

    One issue is waterproofness. This can be solved with a plastic bag such as aquapac or Eastman or perhaps an inexpensive ziplock bag. The Eastman link will also yield some other sources for waterproof bags, while the Aquapac link also has some waterproof cases with extra protection for the faceplate. The units can be operated while remaining inside the protective cover although stylus operation can be a bit tricky. Some bags are large enough to contain the gps as well which will work fine while inside the bag.

    There are many cases available for palm units which offer some protection but for hiking use they generally fall a bit short of the mark. For mechanical protection you might want to look at the armored unit from Otter Box. This box, based on an earlier storage box, allows the palm to be used while providing shock protection. There is a clear plastic panel on the front that provides viewing and stylus access and a belt clip accessory provides a place to carry your palm. Unfortunately the current model cannot be used with a gps attached unless the gps is really small. Future models are planned with cable access. Another armored unit called active armor is available with specific support for handspring Visor extension modules as is GummiGuard which also supports some of the palm units.

    Another suite of cases is available from PocketGoods. They have protective cases with room for CF cards and have cases with a serial port connector on the box that is suitable for a GPS attachment. They have cases for Palm units even though the page starts with pocketpc.

    Data Acquisition

    Sometimes a gps can be used alone for data acquisition in the field but there are times when other input data may be needed as well. There is a module called Silver Finger that may be just what is needed. It is a small unit that provides gps input (NMEA) along with an onboard temperature sensor, two A to D converters, four digital data lines, and a counter.


    1. For mobile use the need to use a stylus can be a problem. Unfortunately many of the programs insist on navigating via menus and it can be hard to click menus in a moving vehicle. One solution is to use a finger stylus. This device is inexpensive and much easier to hit what you want.

    2. Users that have rechargeable batteries in their units may find that a field charger will save the day when hiking. These chargers are simply a box with the appropriate connector on them and contain regular throw away batteries. They can be used to provide a quick charge to the builtin battery. They can be purchased at

    3. As with other gps receivers, palm receivers can often benefit from an external antenna. If they won't accept one then a re-radiating antenna may be the solution. They are readily available from a number of sources. These can improve lock times and susceptablity to noise. They may also be necessary if the windshield of your car has a metallic finish built-in, as some do. One source for a battery powered unit is

    4. When an Palm unit is used in a car the shiny screen can have mirror like reflections than make the data difficult to see. One solution to this problem is to use a screen protector like the ones from PPC-Techs. These protectors have a matte finish that can significantly reduce reflections. Another protector that reduces or eliminates glare is one from Brando Workshop.

    5. Mac users should check with Mark/Space for potential solutions to sync problems.

    Back to main palm page

    00/1/17 initial release
    00/1/22 added hardware translator for earthmate
    00/2/14 discussion on visor and more earthmate stuff
    00/2/25 added a bit more earthmate and palm hardware discussion
    00/3/1 added IIIc support and more visor stuff
    00/3/2 added trouble shooting hints
    00/4/1 withdrew IIIc Rand Unit and added aprs reference for handspring
    00/4/21 added and corrected some Magellan data
    00/4/25 added cable data to this page, added pretec gps. rearranged page
    00/5/7 added Magellan cable. Updated handspring and Rand McNally hardware data.
    00/7/6 added information on Rand McNally status screen program.
    00/7/11 added hacks discussion
    00/7/31 added Geo Discovery
    00/8/7 added mounts section
    00/9/2 added Sony hardware and more on Visor serial mods.
    00/10/22 added Magellan gps companion.
    00/10/26 added new Rand McNally units.
    00/11/17 added earthmate cable for visor.
    01/2/20 added cable for visor and modified other discussions.
    01/3/5 added Sony serial port wiring and serial port wiring for laptops
    01/3/16 added remote power for Palm V.
    01/06/16 added hubclub line
    01/7/6 added palm pro Rand McNally connection.
    01/8/6 added golf unit and softreset.
    01/8/15 added rechargeable batteries.
    01/8/23 added pawgo site and short discussion of M500
    . 01/11/23 reformatted to highlight gps hardware and Delorme solution
    01/12/01 added some M500 support.
    01/12/22 added battery kits form palmgear.
    01/12/30 added Navman M500 support.
    02/3/9 made a new commercial section with a table of cable companies
    02/3/19 added new case section.
    02/3/20 Data acquisition section.
    02/4/22 added armor unit and extension for GPS Companion V.
    02/4/25 added gummiguard
    02/05/4 added connector sources
    02/06/17 added cradle modification link for M500
    02/08/20 added mark/space palm V gps cable adapter.
    02/09/18 added tips.
    03/01/14 added RadioShack.
    03/07/31 removed RadioShack and added Sony connect data.
    03/11/04 added pcmcia unit and improved intro.
    03/11/12 added tips.
    04/03/01 added Kirrio.

    Dale DePriest