RS-232 (serial) <-> eTrex proprietary port
You have a Garmin eTrex GPS unit and you want to make a cable quickly so you can download your data right away. I'll show you how to make such a cable but remember that this is quick and easy not quick and sturdy.
Note the DB-9F and Garmin pin out:
- DB-9F pin 2 <-> eTrex OUT
- DB-9F pin 3 <-> eTrex IN
- DB-9F pin 5 <-> eTrex "-" aka ground
materials:
- old credit card (or maybe even your current one!)
- DB-9F (female) plug and cable (I cut the tail off an old serial mouse)
- Cut the credit card up into a slab that will fit into the eTrex cable input mold.
- Assemble the serial cable and test it with a multimeter, battery and a led, or some sort of conductivity test to find the right wires/pins for the hookup.
- Make some holes in the credit card right where the terminals are on the eTrex.
- Push the wires through the holes and "ball them up" (very technical term meaning to scrunch or push them into one little individual mound each so they don't contact one another).
- Plug it all in and test a download.
Warning: Do not use this cable to update your firmware until you perform a few downloads to insure everything is working correctly. Keep GPS unit on a stable surface and do not move the cord while communications are in process. Do not trust the connection as the scrunched up wires can be easily unschrunched and short out! A little soldering iron would firm up the situation.
Now that we have that little warning number out of the way lets see some pictures!
Here is the credit card plug with the scrunched up wires. I got the idea for this from the pfranc.com page. Go to pfranc.com now and order a couple of Larry's awesome molded ePlugs. With the ePlug this cable will be sturdy!