This version eliminates the need for the expensive MC-35 and even the special 10-pin connector. I’ve opted for a quick GPS receiver and encased everything in a small black box with a flash shoe mount. Because it is powered through the camera’s power source, a switch on the side of the box turns off the GPS. Version 3 should include a battery, rechargeable through a USB connection.

Read on for directions on how to create your own GPS.

Parts List

1. 4.7Kohm resistor (x 2)
2. 10Kohm resistor
3. 2.2Kohm resistor
4. NPN Transistor
5. IC PC Board
6. SPST Micromini Toggle Switch
7. 3x2x1″ Project Enclosure Box
8. USGloblSat EM-406A GPS
9. Remote Cord for Nikon D200 – find a cheap (<$10) one on eBay
10. Small cable ties
11. Velcro with a sticky mount
12. Epoxy stick

Tools Needed

1. Soldering iron & solder
2. Wire cutters
3. Needlenose pliers
4. Exacto knife
5. Patience

Overview
It’s quite a simple project; just four resistors, a capacitor, the GPS, a switch and some soldering. The goal is to make it tight so it fits in a small enclosure that can be mounted on the camera. I prefer to do a dry run without any soldering to see how it all fits together; I would suggest you do the same.

Disclaimer
Although I have used this successfully with my camera, I cannot guarantee that it will not harm your camera, even if all directions are followed exactly. By constructing this GPS following these directions (or even using them as a basis for your own project), you do so at your own risk and agree to hold me harmless from any damage done to your camera.

Wiring Diagram
The wiring diagram depicted above is the top view of the PC board. My handwriting shows four resistors (r1, r2, r3, r4), a transistor (with emitter, base, and common leads), Red, Black, and White wires, and the six leads to the GPS (number 1 through 6).

Step 1
Attach the four resistors to the PC Board as shown.

1. R1 – 4.7K ohm
2. R2 – 10K ohm
3. R3 – 2.2K ohm
4. R4 – 4.7K ohm

Step 2
Attach the transistor to the PC board, carefully placing the base, common and emitter leads in their proper holes on the board.

Step 3
Attach a wire (preferably red) between the PC board and the switch. This will be used to cut off power to the GPS.

Step 4
Cut the switch off of the cheap remote cord to expose the measly three wires in it. If you happen to have a 10 pin connector with ten wires then you will have to do things a bit differently.

Attach the red wire to the other terminal of the switch. Note the picture depicts a SPDT switch and has an additional terminal. You can choose to leave the switch out as it is a bit obtrusive on the box but doing so will keep the camera active and drain the battery quickly. Alternative, you may prefer a switch with a lower profile such as a slide switch.

Attach the black and white wires to the PC board. The location of the white is depicted with a “w” in the wiring diagram although the picture should help to clear up where it goes.

Step 5
Take the six pin cord for the GPS and cut off one end. I made the mistake of cutting it in half, giving me a much shorter span of wire to work with.

Attach the black wires, numbered 1 through 6 to the locations on the PC board. Wire 3 is connected to the emitter and wire 6 to common of the transistor. The other four wires should be readable.

Step 5a
Solder the connections on the underside of the PC board, if you haven’t done so already. I like to fit everything together first and when I’m happy, do the soldering and then snip the extra wire. You can see from the image that I am not an expert solderer; just make sure that the solder does not stray.

Step 6
Attach the GPS to the PC board using velcro, connecting the white 6-pin connector to it.
Wrap a wire tie around the wire and through a hole in the PC board, make a tight connection to provide strain relief. This is a very important step because if it is not done, one tug on that wire will disconnect something on the PC board making the GPS inoperative.

The device is finally beginning to take a recognizable shape!

Step 7
Create two holes on the long side of the enclose, one to fit the wire through and the other to hold the switch. Make the hole for the switch the size specified for the switch. Remember both the switch and wire will be on the same side as the 10-pin connector on the Nikon body with the switch to the front of the box. If the holes will be different sizes, pay careful attention to where the holes are made.

Step 8
Carefully insert the PC board, wire, and switch into the enclosure. It should fit in there tight. Make sure to secure it to the box if there is anything loose. You can screw the top cover onto the enclosure; we are almost done!

Step 9
This is the tricky part: making the connector. With an exacto knife, strip off the rubber on the 10-pin connector of the cheap remote cord. The goal is to get the plastic piece with the 10 holes and three pins. With patience, the rubber can all be removed and the pins extracted. The pins must be located in different holes than their original location. You’ll want to cut the wire to a size that would ultimately fit between the enclosure and the camera with just a little bit of slack.

Ultimately the wires are connected to the pins in the following sequences. This image is looking into the barrel of the connector.

1. White wire – pin 1 (receive)
2. Red wire – pin 3 (power)
3. Black wire – pin 7 (power ground)

You’ll want to hook GPS power to pin 3 on the camera which always has +5V while the camera is active; note that by keeping the GPS on, this pin will continue to have a +5V supply as receiving the NMEA data keeps the camera active. Using pin 2 to power would keep the power to the GPS flowing even while the camera is off and this would be sure to drain your battery quickly.

It takes a bit of patience and luck to extract the pins, clean them, reinsert in the correct location and solder the wires to the pins. Be careful as the pins are often numbered looking into the connector although you will be soldering on the outside of the connector.

Step 10
Once you have confirmed everything is correct, plug it into your camera and turn the camera on, making sure the switch on the box is in the on position. You should start to see the flashing GPS symbol on the display of the camera within a few seconds. If you don’t, turn off the camera and disconnect the connector and recheck your work. After a bit, the GPS symbol will stop flashing and will be solid (you may need to have a clear view of the sky for a lock to be made). At this point all we need are a few finishing touches.

Carefully disconnect the module from the camera. To make the connector secure, fashion some epoxy in the shape of an elbow connector around the bare wires and the 10-pin connector making sure to secure the pins in the connector. Make certain to leave enough room on the connector to plug it into the camera (about 1/4″). Also, make the elbow bend such that it lines up with how you want your cable to flow. Hopefully you can do a prettier job than I did!

Finally, to make the mount, fashion one out of a hot shoe adapter or take the mount from the bottom of an old, broken flash and mount it to the base of the case. This will give the GPS a place to sit while taking photos. You may need to get creative with how to attach it. The next version will need to add a flash mount on top of the GPS so we can use the GPS and flash at the same time.

Good luck! I look forward to hearing your results and would love to see pictures of your projects.

A homemade solution can be had for about $175 and turns out is quite easy to do, provided you can acquire the MC-35. Read on for details.

NOTE! My next GPS project for the Nikon D200 (just completed) does not rely on the MC-35 and can be built for less than $100 and is much smaller and more manageable. I will be posting information about it soon.

Overview

The idea is to replace the most expensive item (the GPS) with a comparable product and to alleviate the bulkiness of the GPS by removing its power supply and replacing it with power from the camera.

The GPS is replaced by a OEM Garmin GPS (GPS18 LVC – no software, no connector, lower cost) and is powered by the 5vdc supply, available from the 10 pin connector on the front of the camera (can be tied into the MC-35 with a simple modification).

Warning

This procedure involves soldering very small areas on a circuit board. Performing these steps will certainly void the warranty on your expensive MC-35 GPS Adapter Cord that you waited so patiently to receive. There is also the possibility that your even more expensive camera could be irreparably harmed due to faulty soldering. I cannot be held responsible for any damage done as a result of this procedure. Consider this fair warning and only proceed at your own risk if you agree to these terms.

Part List

• $99.95 Nikon MC-35 GPS Adapter Cable Available (sometimes) at B&H Photo
• $65.79 Garmin GPS 18 LVC (OEM Series) NOT USB
• $1.79 9-Position Female Solder D-Sub Connector Radio Shack part #276-1538
• $1.79 9- and 15-Position D-Sub Connector Hood Radio Shack part #276-1539
• $5 (or less)  Broken or very cheap flash unit (hot shoe needed)

Procedure

1. First, acquire the MC-35. It took at least four months to get mine.
2. Supply power to pin 9 (Ring Indicator) of the DB9 connector on the MC-35.
1. Remove four small screws from top of MC-35.
2. Open the plastic box carefully; note the bottom of it comes off leaving the cable and circuit board with the connector.
3. Very carefully, solder a wire from Vcc to pin 9. The Vcc terminal is clearly labeled on the circuit board. You could also choose Vbat which would have a continuous power draw on the camera’s battery. Vcc is only active while the camera is active. Note that if the camera is receiving GPS data, the camera remains active. Pin 9 on the DB9 connector is the rightmost pin on the row of four pins looking at it si that the 4-pin row is on the top.
4. (optional) If you have a voltmeter you may want to make certain that your soldering is correct.
5. Close the MC-35. Note the rectangular rubber connector is placed vertically in the hole on the other part of the connector before closing it.
3. Attach the female 9-pin D-Sub connector to the GPS cable, trimming the cable to the desired length.
1. Determine the length of cable attached to the GPS you will need. I would suggest allowing extra cable because it is much easier to shorten the cable length than to enlarge it.
2. Strip two inches of the black casing from the end of the GPS cable. This should reveal six wires: two black, one red, one green, one white and one yellow. The yellow cable is not used and can be safely cut back for this application.
3. Solder the black wires (Ground) to pin 5 of the DB9 connector. Pin 5 is labeled on the back of the connector; it is the rightmost pin on the top row (with 5 pins) looking from the back of the connector.
4. In the same fashion, solder the red wire (Vin – 5V) to pin 9 (bottom rightmost pin). This is going to match the 5V on pin 9 supplied by the D200 by pin 3 of the 10-pin connector (through the modified MC-35).
5. Solder the green wire (receive data) to pin 3.
6. Solder the white wire (transmit data) to pin 2.
7. Attach the connector hood to the DB9 connector.
4. (optional) Remove the hot shoe from the base of an old (or broken) flash. Determine a method to connect the GPS hockey puck to the shoe. This will prevent fiddling with the puck while trying to take pictures. Note the bottom of the GPS has a magnetic base. Do not let it come in contact with your Compact Flash as it may destroy any information on the card. I would also be weary of getting it too close to the camera as the magnetic surface may harm the camera. I chose to leave a long length of cable attached to the GPS and then keep the GPS in a pocket or on the ground while shooting.
5. Plug the MC-35 into the DB9 connector of the GPS and attach the 10-pin connector to the D200. If everything has been done correctly, a flashing GPS will appear on the LCD display on the top of the GPS. Then the GPS sign stops flashing and remains, a location fix has been achieved and GPS information is available to the camera. Pictures taken now will embed the GPS coordinates into the EXIF information of the digital image.

Unfortunately, the Garmin GPS 18 take a while to lock on to a signal and is not as sensitive as other GPS devices. Also, I can only have the camera on for about two hours before the GPS drains all of the life out of the battery. When not in use, it is wise to either turn off the camera or disconnect the GPS from the MC-35.

My next project aims at reducing the expense and complexity of this project. Keep reading for details.