Navit has been successfully ported to TomTom devices. However, the TomTom port is still experimental and some features do not work properly yet. This page lists the things that have been done so far and contains some detailed instructions on cross-compiling Navit and some required libraries for TomTom Linux. It also contains some setup instructions for using pre-compiled binaries available at http://www.navit-project.org/~xenos1984/navitom.tar.gz.
Lots of information on the hardware of various TomTom models has been collected at www.opentom.org (trough archive.org). These devices feature an ARM920T or ARM926EJ-S CPU.
GPS and GPS week rollover
Devices with SiRFstarIII receiver like Tomtom go 730 work without any additional driver. They output NMEA messages which can be read directly by navit. Since GPS week rollover the firmware fail to get a fix after suspend. Clearing the old ephemeris data bring the firmware to work again. Use this script to clear the receiver before you start navit.
#! /bin/bash if [ $# != 1 ] then echo usage: `basename $0` path_to_nmea_device exit fi stty raw 4800 <$1 || exit if grep -m 1 GPRMC $1 |grep -q ,,,,, then echo '\r' >$1 echo '$PSRF101,0,0,0,0,0,0,12,2*16\r' >$1 fi
On the other hand Devices with Global Hammerhead v1 like Tomtom one XL have a closed source driver named "gltt" which translates the gps messages into real NMEA messages.
Also this firmware has such a bug. To get a fix set the date with "date -s 201907040957" and then call gltt with the option -fix_start cold
Nearly all Tomtom Devices feature 32MB of Memory so it is the most limited resource we have on the device.
Rest of hardware
As shown in the Hardware Variants table from opentom.org there are more features that a Tomtom contain which are not relevant for now.
Tomtom Software options
To use navit on a TomTom device you have the following options. As always in live there are advantages and disadvantages which you can find below. The table should help you to decide which option is most suitable for you.
|Original||Plugin||NavitTom (custom embedded System)|
TomTom GPS settings
Devices with SiRFstarIII receiver like Tomtom go 730 work with this setting:
<vehicle name="Local GPS" profilename="car" enabled="yes" active="1" lag="14" source="file:/dev/gpsdata" follow="1" >
Devices with Global Hammerhead v1 like Tomtom one XL work with this setting:
<vehicle name="Local GPS" profilename="car" enabled="yes" active="1" lag="14" source="file://var/run/gpspipe" follow="1" >
In a standalone setup without Tomtom environment Global Hammerhead v1 need a closed source driver named "gltt". It can be extracted from a original ttsystem file. gltt write to the named pipe /var/run/gpspipe
gltt is called like this sample: gltt -baud 115200 -periodic 1000 -fix_start cold -rftype HH_4L
You can get some informations about used device names in /proc/barcelona or the built in flash drive.
RAM memory issues
Most Tomtom devices like TomTom one XL have only 32MB RAM. Navigation in cities is almost unusable. Devices with 64MB like Tomtom 730 work with reduced routing depth like route_depth="4:15%,6:1%,8:10000,18:2000"
It is possible to build a full custom setup with the toolchain from https://github.com/george-hopkins/opentom With it its possible to activate swap to SD card. The toolchain is outdated and need several manual changes to compile.
Using pre-compiled binaries
There are some pre-compiled binaries available at http://www.navit-project.org/~xenos1984/navitom.tar.gz (this link always points to the most recently compiled version). See http://www.navit-project.org/~xenos1984/release/ for other / older versions. I have tested them successfully on a TomTom GO 910. For other TomTom models, it may be necessary to edit the navit.xml config file and adjust the screen size, the GPS data source...
In order to use the binaries above, unpack the file in the top directory of a TomTom device. Get some Navit map and place it in the navit/share/maps folder on your TomTom. Edit the config file navit/share/navit.xml as described below. Unplug your TomTom from the computer and let it reboot. If you touch the screen and enter the TomTom main menu, you should see a Navit icon (on the last page). Press this icon and a grey screen will appear. Be patient - it may take a few seconds. But finally you should see a map. Have fun!
A more recent version (R7045) can be found here https://1390-30791823-gh.circle-artifacts.com/2/tmp/circle-artifacts.xgv65b2/navitom.zip It does not provide a config for 320x240 screens but it has translations and multilingual speech.