SatNav for the SilkRoute.

Anybody who has used a modern SatNav to find their way round the back-streets of a strange city would not willingly do it without one.

For between 150 and 300 Euros you can buy a self contained unit to mount on the windscreen of your van that will guide you around most of Europe and North America. "In 200 meters turn left, then immediately turn right." "In 300 metres you have arrived." Easy!

Unfortunately this sort of SatNav will not let you find the delightful camp site on the west coast of Mexico at N 18.204445 W 103.1181901 nor will it tell you if you are on the N317 or the N318 in China.

Even if your European or North American SatNav will let you enter the coordinates of your destination, most of them will not guide you there unless they have a detailed digital map of the area. Suitable digital maps of most of Asia, Africa, Central and South America are not currently available.

The traditional (i.e. a couple of years ago) solution to this problem was to use a "real" GPS2 with some sort of World map, which, whilst not very detailed, was a great deal better than nothing.

The problem with this solution was that a "real" GPS either had a small monochrome screen or was very expensive. Either way they used proprietary maps, which, if they were available were also expensive.

To get round this problem some people (including me) used a small notebook computer connected by a serial link to a "real" GPS.

Because small notebook computers (with say a 10 inch screen) are typically far more expensive than medium sized ones this was quite an costly solution. Also because the cab of a campervan being driven on rough roads is a very hostile environment it demands a robust and reliable computer (particularly the hard disk). After four years of abuse (and a new disk drive) my second-hand Sony Vaio PCG-SR21K finally died in 2007. (In passing it is worth saying how impressed I remain with its performance. On many occasions it became too hot to touch in the sun (in Pakistan) and on other occasions it was covered in frost in the morning (in Tibet) and for thousands of kilometers it was vibrated by corrugated roads.)

The rest of this web page concerns my experiences in assembling a SatNav for the SilkRoute using low cost new equipment. (My previous system was bought second hand on eBay to exactly match my "main" notebook computer. This allowed me to buy a SatNav notebook without manuals, software or external CD disk drive at a much reduced price.)

My ideal SatNav for the SilkRoute would:

  1. Provide the same or better standard of automatic routing and voice directions as a consumer SatNav (Within Europe and North America).
  2. Provide moving map navigation (Outside Europe and North America).
  3. Allow me to scan or photograph paper maps and use these for moving map navigation.
  4. Guide me to an arbitrary waypoint3.
  5. Enable me to store, organise and display large numbers of waypoints.
  6. Allow me to follow routes4 derived from tracks5 provided by other overland travellers.
  7. Record my track and selected waypoints.
  8. Have a screen larger than a consumer SatNav but less than (say) 10 inches.
  9. Operate from 12 or 24 volts.
  10. Have no moving parts.
  11. Allow data to be moved to and from my (main) notebook computer.
  12. Cost no more than 500 Euros.

In the end I slightly exceeded the 500 Euro limit but the resultant SatNav also:

  1. Provides Internet access via my Quad Band GSM phone using GSM and GPRS.
  2. Provides Internet access via WiFi when available.
  3. Runs Skype (given a WiFi connection).
  4. Sends and receives SMS (text) messages.
  5. Plays 1000s of MP3 tracks via a suitable vehicle radio.
  6. Translates French/German/Spanish to/from English.
  7. Links to my "main" notebook computer via a wired or wireless network.

Basic Hardware.

My SatNav for the SilkRoute is based on the delightful Asus Eee micro-notebook.

If you shop around (in January 2008) you can get the Asus Eee 701 with a 4GB solid state disk for just under £200 UKP (say 270 Euros).

The Asus Eee 701 comes three USB ports an MMC/SD/SDHC memory card slot, a built in microphone, a built in web camera, a 10/100 Mbps LAN port, WiFi (802.11b/g) and a 15-pin D-sub monitor port. The version sold in the UK does not include a modem.

This sub-miniature notebook comes with a version of Linux installed. Configured this way it makes a great second notebook when traveling. I had mine sending and receiving email, surfing the web and making video6 Skype calls within 10 minutes of unpacking it!

However for this SatNav application I have installed an old (licenced) copy of Windows 2000. You can also use Windows XP if you have a suitable licence.

Before considering the software requirements there are two additional bits of hardware needed. The Asus Eee comes with a universal mains power adaptor, but for this application you will need to run it from 12 (or 24) volts. Because the Asus Eee only requires around 2500 milliamps at 9.5 volts you don't need to use an expensive 70 watt notebook power supply. I used two Hibaba 12V (Cigarette Lighter) Power Adaptors7 from Amazon at a cost of £4.90 UKP each (say 14 Euros in total).

These power adaptors work from either 12 or 24 volts and can supply 2000 milliamps (each). In practice one power adaptor may be sufficient for normal use, particularly if you have a 24 volt supply. However if you make your Asus Eee work very hard (WiFi, GPS and continuous loud audio) without the engine running (i.e. ~12 volts not 13.2 volts input) then you will have problems with just a single power adaptor.

Warning: Running your Asus Eee from a non-standard power supply may invalidate your warranty.
Getting the voltage or polarity wrong may well damage it.

The second piece of hardware you will need is a GPS receiver. Whilst it may be possible to use an existing Garmin or Magellan GPS with a serial-to-USB adaptor it is a lot simpler and neater to invest in a USB GPS "mouse" (they are only called a GPS "mouse" because they look a lot like a computer mouse and these look a bit like a real mouse).

You can pay anywhere from about £20 UKP to around £70 UKP for a GPS mouse. Modern receivers are far more sensitive than the older ones and are faster to first fix (i.e. they start-up more quickly). Some are more waterproof than others, this will be important if you intend to mount the receiver outside.

I used a Navibe USB GPS Receiver with a high sensitivity SiRF Star III Chipset (GM720). Yours for just £9.99 UKP on eBay but with a £14.99 shipping cost from Hong Kong. So the real cost is £25 UKP (say 34 Euros).

Warning: Most older USB GPS receivers send NMEA sentences at 4800 Baud, the GM720 is factory set to 9600 Baud and notwithstanding what it says in the specification sheet you can not change this with end-user tools, only special developer software. This is not a problem as both Fugawi and PC Navigator (see below) can be set to 9600 Baud. If you fail to set Fugawi to 9600 Baud it just won't work. PC Navigator, if set on autodetect, will eventually try 9600 Baud but it may take several minutes.

Warning: Because of the way USB-to-serial drivers work under Windows 2000 and Windows XP if you change the USB port your GPS Mouse is plugged into it may be assigned a different COM port number. For this reason it is best to stick with one USB port.

SatNav for Europe and North America.

For SatNav around Europe and North America I have installed PC Navigator 7. This software provides all the normal SatNav facilities including voice guidance. (So that you can see the size and quality of images on the Asus Eee screen all the images below are 800 x 480 pixels and captured from my Asus Eee. If you have had trouble reading the 3 or 4 inch screen found on most commercial SatNavs you might want to print one of these images so that it is 150mm wide and place it where you would hope to mount your Asus Eee SatNav.)

The forward facing loud speakers mounted beside the screen of the Asus Eee are adequate for voice guidance (but you would not want to listen to much music using them).

NB. Although PC Navigator can be used with a touch screen it does not require one. After a little practice using the touch pad on the Asus Eee becomes second nature.

The more unusual features of PC Navigator 7 that should be of particular interests to SilkRoute club members include:

1) Very good coverage of most of Europe including the less popular countries. For example PC Navigator will provide directions (and voice guidance I assume) from my house in the UK to Londra Camping in Istanbul via Tirane in Albania (it reckons it's about 3673 km). There is also some coverage of Russia east of Moscow.

2) A choice of Car or Truck mode.

The rather sparse PC Navigator 7 manual says "Truck mode will be more selective about sending you down narrow lanes etc."

That sounds like a good thing for anybody with even a modest sized motorhome.

3) The ability to store a record of where you have been (i.e. a track).

Tracks are stored as raw NMEA format sentences in a text file. These files can be directly imported by Fugawi (see below), where they can be reduced and stored in Fugawi track format. Alternatively they can be converted by GPSBabel into a format that can be displayed on Google Earth (above). (You will then be able to settle the argument with the human navigator about just how close you were to the camp site you missed in the last town!)

4) You can easily import data. For example the list of 10,754 Aires in Europe found on Wohnmobil Stellplätze. You can then define an arbitrary area of the map and search for Aires in that area.

In fact PC Navigator lets you link a collection if imported waypoints (POIs3) to an external database (for example an Excel spreadsheet) in a way that lets you update your spreadsheet and then automatically update your waypoints in PC Navigator. The icon used to represent your imported waypoints can be fixed or determined by a field in your database (i.e. a column in your spreadsheet). The location of your waypoints can be linked via latitude and longitude or postcode.

When you install PC Navigator you can select which countries are copied to your (solid state) disk. If you install all the maps you will need about 3.2GB of free space. To do this means you will have to add a SDHC memory card to your Asus Eee (see below).

Moving Map navigation outside Europe and North America.

For moving map navigation outside the area covered by PC Navigator 7 I have installed Fugawi version 3 (for which I already had a licence). The most recent version of Fugawi is Fugawi Global Navigator 4.5 which costs around £67 UKP (around 90 Euros). The on-line activation of this version is intrusive, make sure your system is stable and backed up before activating this version of Fugawi.

A slightly cheaper alternative to Fugawi is Ozi Explorer available for about £50 UKP (around 70 Euros).

Although you can use Fugawi to find specific waypoints without additional maps it is far more useful if you add maps of the places you intend to visit. Maps for Fugawi come in two types. Vector maps which (in general) you have to buy and raster maps (images) that you can create yourself from paper maps. Even if you can buy a vector map of your target country it is very unlikely to be of a quality or resolution suitable for reliable street level navigation.

With Fugawi you can scan sections of your paper maps, calibrate these and use them for navigation. It is best to use an A3 or larger scanner. You can only calibrate a paper map if there are latitude and longitude lines printed across the map (not just at the edges). Even with great care do not expect your calibrated maps to be very accurate, but they are a great deal better than no map. See here, here and here for examples of inaccurate paper maps.

One of the most useful features of Fugawi is the ability to load and organise very large numbers of waypoints (typically of potential overnight parking places). Sets of waypoints can often be downloaded from travel web sites or culled from guide books.

Above: A waypoint for the Centro Turistico near Granada in Nicaragua (culled from the very useful book 99 Days to Panama) is being selected.

Above: Fugawi has selected the best available map (that is the one with the largest scale, in this case 1:755,000). The red arrow shows our current position and direction of travel. The blue line shows our actual track (note that the map does not show the road leaving Granada to the south west). The navigation window on the right shows the waypoint we are aiming for: Centro Turistico as well as our current speed and distance to go (DTG). (Because this screen image was actually made in my office in the UK the speed is 0.0 and the DTG is 8638.1 km. The red arrow has been added.)

Although Fugawi can help guide you towards a waypoint and display your position on a (raster) map these two features are independent of each other. Fugawi will simply indicate the straight line distance and direction to your target without reference to any roads shown on the (raster) map. Far less helpful than PC Navigator (in areas where detailed digital mapping is available) but still very useful.

It is not yet practical to use Google Earth for live navigation (unless you have very high speed satellite broadband and unlimited funds). However you can use Fugawi 4.5, Google Earth and a good home broadband connection to create calibrated raster maps that you can save and use on the move with either Fugawi 4.5 or Fugawi 3. It would only be sensible to create such maps around particularly difficult to find waypoints.

Additional Hardware.

The Asus Eee 701 comes with a 4GB solid state "disk" drive. Whilst it is easy to load all the required software (under Windows XP or Windows 2000) onto this "disk" there is then only about 2.5GB available for maps.

All the European maps for PC Navigator occupy about 3.2GB. My collection of around 300 raster maps for every country in Central and South America, Russia, Mongolia, China and much of the Silk Route occupy another 1.3GB.

Obviously nobody really needs all these maps loaded at one time and it is possible just to load the ones you need. However as the Asus Eee has a memory card slot and SDHC 8GB cards are now available for about £30 (say 40 Euros) you can easily expand your Asus Eee to provide enough space for almost all the applications you might need whilst traveling (except for the storage of digital photographs, for that you will need an external USB disk drive of say 80GB).

Warning: Although SDHC cards look like MMC and SD cards they are not the same. You can use MMC/SD cards in the Asus Eee, but if you want more than 2GB you will have to use a SDHC card. Not all SDHC cards seem to work reliably in the Asus Eee (my digital camera now has a Kingston 4GB card in it as a result of getting this wrong).

The one card that everybody seems to agree works is the Patriot SDHC 8GB Class 6 card.

Setting up your Asus Eee as a SatNav under Windows XP or Windows 2000 requires access to an external USB CD/DVD disk drive, a second computer and broadband access to the Internet, all things you probably will not have whilst on the road. So having put all your navigation eggs in one Asus Eee basket it is important to have some simple means of restoring your system "disk" in the event of it becoming corrupt.

With all the required software installed (but without the maps) the entire Windows system occupies less than 1.5GB.

Rather conveniently this means you can back up and restore the system to a 2GB bootable USB flash drive (cost £7 UKP or about 10 Euros) using BartPE and Drive Snapshot.

Because the Asus Eee can boot into BartPE from an external USB  flash drive you can then use Drive SnapShot to restore the MBR, the Partition table and the entire Windows system in about 45 minutes with no additional hardware.


  1. There are three common methods of giving the latitude and longitude of a location. Getting them confused can result in considerable error. The easiest method to understand is to use degrees and decimal degrees (DD.dddddd) as above N 18.204445°.

    Alternatively you can use degrees, minutes and decimal minutes (DD MM.mmmm). There are 60 minutes in one degree (thank the Babylonians for this, they apparently counted finger and toe joints not just fingers). Thus N 18.204445° converts into N 18° 12.2667'.

    The third method is to use degrees, minutes and seconds (DD MM SS). Thus N 18.204445° converts into N 18° 12' 16".

    See here for more information and a conversion tool.

  2. The difference between a SatNav and a GPS with maps is only one of emphasis, target market and (often) price. Both perform nearly the same function.

  3. Waypoint: A set of coordinates (latitude, longitude and possibly altitude) that identify a point in physical space. For example a recommended wild camping place. See here for some useful waypoints in Central and South America. Waypoints are also known as POIs (points of interest).

  4. Route: A series of waypoints to be followed to a destination.

  5. Track: A series of waypoints recorded whilst moving.

  6. The built in web-camera works under Linux and Windows XP but so far not under Windows 2000.

  7. The two power adaptors need to be wired in parallel (both input and output). Use the 9 volts setting and the 4.0 x 1.7 millimeter tip, tip/centre positive. Take care to get the polarity right.

    Alternatively if you don't want to get your soldering iron out you can use this 3A Digital Car Power Adaptor from Maplin at about £25 UKP (about 34 Euros). This is far neater way of powering your Asus Eee.

    There is now a car charger (works from 10 volts to 18 volts, not 24 volts) specifically for the Asus Eee available from Shop Brando in Hong Kong at $18.00USA plus $3.00USA Shipping worlwide. I have not tested this one.

Home - This page last changed on 2008-02-05.