From Shapefiles to a Custom GPS Basemap

For those of you who have older than the latest generation of handheld units, custom basemap creation is a little more round about. I recently learned that Garmin's newer lines allow for easier user creation.

I had set of trail networks that I created in ArcGIS (and stored as shapefiles) and wanted to have those as a basemap on my handheld unit. Here are the steps I took to achieve this.

Software you will need to download:

• cGPSmapper (free version, available for personal use)
• Pro SendMap (free version, available for download from cGPSmapper site)
• GPSMapEdit (shareware)

Steps:

1. Download and install the above software.
2. Run GPSMapEdit
3. Choose: File -> Import -> ESRI Shape (*.shp)
4. In the dialog box, choose your symbology from the list -> Next
   
5. Choose which field you would like for your label by clicking on the field name(optional) -> Next
6. Set the coordinate system of your dataset -> Next -> Finish
7. Repeat 3-6 for any additional shapefiles you want to add. You can mix polygons, polylines, and point data. Note: each importation is a irreversible step, if you screw up you will need to start the basemap over. I often make more maps with few components, and then the user can turn on and off the maps on the GPS unit itself.
8. Open Map Properties (File -> Map Properties.
9. Under Header Tab enter an eight digit number for the ID. Whatever you would like but if you have multiple maps, I'm assuming you should make them different from eachother (if using a Garmin unit)
   
10. Under the cGps Mapper Tab, change "Map is transparent" to "Y - Transparent map without background object". Apply your changes and close out of Map Properties.


11. Save map in Polish Format (.mp)
12. Export to Garmin/CGSmapper: File -> Export. Save as an .img file and run the prompt that comes up in the dialog box. You will need to set the directory to where cgsmapper.exe is installed.
13. Run sendmap20.exe
14. Add the all the .img files you would like to upload to your GPS


15. Connect and turn on your GPS.
16. Click 'upload maps to GPS' (Note: this process will overwrite the maps in your GPS, so add all your maps at once, if you would like to do otherwise you can try the "Sync GPS" option, but I haven't tried it).
17. The map(s) should now be added to your GPS (if you have trouble with your GPS getting stuck on 'Transferring Data', check that your SD card is seated properly).

There are also many stock .img basemap files out there that can be uploaded in a similar fashion.

Notes on this process:

cGPSmapper is no longer being updated.

A warning from cGPSmapper: Uploading custom basemaps to certain brands of GPS units can void the warranty. The cGPSmapper program will tell you this in the EULA, but also that there have been no problems with the program damaging GPS units in the past. Garmin's IMG map format is closed and undocumented, so this was reverse engineered.