GPS interface for Sony Clie
T/NR/NX/SL/SJ series
Check my Suunto Vyper interface page
NEW! You can buy a complete cable (actually cable + adaptor) from http://pc-mobile.net/gps.htm model GEST6 for $28.50 + $5 shipping. However, if you want to save $20, and electronics is your hobby then read this page.
Originally I made this interface specifically for Garmin eTrex Venture GPS and Sony Clie SJ30. However, it will work with other NMEA compatible GPS units and Sony Clie T415, T615C, T665C, NR70, NR70V, NX70, NX70V, SL10, SJ20, SJ30 handheld computers that have 18 pin HotSync connector.
If you don’t have one yet, then you will need a serial HotSync cable!
1. Simple interface
HotSync cables have built-in circuit which requires some power to function properly. These cables function properly, if connected to DB9 serial port of a desktop PC, because the internal circuit of HotSync cable is connected to DTR, RTS, CTS (pins 4, 7, 8) of DB9 serial port as a source of +5…12 Volts. If you connect this serial HotSync cable to Garmin eTrex GPS which only has RX, TX, and GND (ground) then the circuit will not work, because DTR, RTS, and CTS pins of GPS serial cable are not connected to anywhere. Actually, the circuit only needs about +3 V to function. You can make an experiment. Connect two AA batteries in series and connect “plus” to pin 4 (7 or 8 will work as well) and “minus” to pin 5 of serial HotSync cable. It will power the internal circuit with 3 Volts. Then connect you GPS output pin to pin 2 (RX) of HotSync cable, and GPS ground to pin 5 (GND). Use two male DB9 connectors as it shown on the picture below. With this set up you should be able to receive data form GPS while running some navigation software (such as Aqua DiveLog GPS plug-in) on you handheld. Don’t forget to set your GPS unit to transmit standard NMEA format. If you are satisfied, then you can make an interface box that will include 2 or 3 AA batteries and two male DB9 connectors. Then you can plug GPS and Sony Clie to this box, and everything should work.
2. Another simple interface
As you can see from the picture above, there is only RX line connected to output from GPS (white wire). I did not intend to send any data to GPS. However, when I started working on interface for Suunto Vyper dive computer, I tried the similar connection with addition of TX line (see picture below). Also I connected DTR lines together (see diagram below).
I tried this connection with Roli’s Suunto interface. Then I found out that 2 AA batteries did not supply enough power, so I tried 4 AA. And it worked. I was able to upload data from Suunto Vyper to Sony Clie. Note that it does not matter which side you plug you handheld and dive computer. The diagram above looks symmetric. 4 AA batteries supply about 6 Volts, and you may also try to use 9 Volt battery. So, if you don’t want to modify original serial HotSync cable, you can make this interface with batteries. This interface will work with both, GPS and Roli’s dive computer interface. I don’t know if it will work with Suunto OEM cable, because I never had one. If it works, please let me know.
3. Yet another simple interface without
batteries
Sony Clie SJ30 and other models described above have 18-pin connector. In fact, some connectors may have 20-pins, but the first one and the last one are not used, so when you refer to pin numbers, you must count only 18 pins in the middle. Moreover, when you hold connector up with gold contacts facing towards you, then pin 1 is the rightmost. (Confusing? Just like sailors say: Mark bottom of the boxes “top” in order to avoid confusion.) Why so many pins anyways? One of them may be what we are looking for, the power source. Pin 10 is +3.7…4.2 V unregulated power output. If you connect it to the place on the circuit board where DTR (CTS or RTS, either one will work) signal should go, then you don’t need any batteries. And finally, you can cut an original GPS cable and solder it directly to HotSync connector instead of DB9 (refer to the picture below).
Important note: Circuit board layout on the picture above may vary depending on the manufacturer of the HotSync cable. You will have to find TX, RX, DTR and GND points by tracking wires from DB9 connector. Also it will not work with Suunto dive computer interface.
For comments e-mail me at nn1i@arrl.net.
Igor Anisimov
January 6, 2003