How to Make a Nikon D200 GPS Mount and Cable
Overview
This page is broken into 4 parts. You are currently poised to read why I went about making a mount for a GPS as well as a cable to hook it to my Nikon D200. Should you want to skip to the making of the mount click here, if you would like to skip to the making of the cable click here, or if for some bizarre reason you would like to skip to the conclusion you could click here.
Encoding GPS into photos looks to me as a technology that will become ever more present in the near future. There are already a few neat things that you can do with it. I personally started this project so I could contribute to wwmx.org as well as create travel logs or perhaps start a site that would contain the world according to my eyes using this software. The latter was created by someone who was fed up with what Red Hen Systems had to offer. I personally fall under this category as well however I went so far as to create the hardware as well.
The cable I created is in essence the same thing as the Nikon MC-35. However the Nikon MC-35 is $150 and is pretty much only available after special ordering it straight from Nikon with a 3-6 month wait time. Red Hen Systems offers a package that has a hot shoe mount and cable for a Garmin geko as seen here however they want $395 for what amounts to 2 special connectors, a serial adapter, and a hot-shoe mount. You can also purchase the GPS with their kit for a whopping $544. At the end I will total up what all the pieces cost me and the savings will be apparent.
There are other howto's on the internet on how to make one of these cables however I have been frustrated about how poorly organized the information is about it. I hope to make this as clear and concise as possible. I also took several pictures that hopefully will illustrate both what I am trying to explain as instructions as well as show how easy it would be to make your own solution.
GPS Mount construction
The mount was easy enough to make. It involves two parts, a hot-shoe adapter and a screw. The screw even comes with my GPS! It doesn't get much easier than this. Now lets meet the players.
This is a picture of the hot-shoe adapter that I got from Adorama after shipping this little thing came to $14.50. If I hadn't done this project in two steps I could have combined shipping with one of the cables needed from the next part.
This is a picture of my newly purchased GPS. I searched around and found it for $99 with free shipping. when it came in the factory packaging there was a screw that held the cardboard in the clamshell to the GPS by threading into its mounting threads. If you buy a GPS new check for one of these as it will save you a run to the hardware store.
This is is the screw that was holding the GPS to its packaging. that wide head on the screw is actually a blessing when it comes time to start building the mount.
Now comes time to assemble all of these parts. First start by removing the top metal plate from the hot-shoe adapter using a small Phillips screwdriver. The result should look something like this
Next I used a pair of pliers and a bench grinder to grind off all pieces of aluminum that stuck above the top surface. This is so that the GPS can rest on this plate. After grinding the plate this is what it looked like.
The next step is to drill a hole through the plate to accommodate our new screw facing the other way through the plate. When drilling this hole make sure to put it closer to one of the holes than the other. The reason is not apparent now however it will help to not allow the screw to turn freely when installing the GPS on the finished mount. Next fit the screw through the hole and check the clearance of the original holes. on should be slightly covered by the head of the new screw. Remove the new screw and grind a flat spot along the head of it so that the hole is no longer blocked. The screw and plate should then look like the picture below.
Below is what is should look like when the screw is put back through the plate with the head ground off. Take notice how the flat spot on the head will prevent it from turning when there is a screw through the hole in front of the flat spot. The reason the upper hole looks oblong is because I originally tried to use the manufactured hole as a guide to drill through the head of the screw. This does not work as the aluminum of the plate is way to soft. I wouldn't recommend trying it.
Now the screw head needs accommodation. Drill out the soft resin of the plastic base just enough to accommodate the head of the screw that is now going through the plate. Be careful not to drill out the threads for the screw that is going down next to the ground off portion of the new screw's head. Luckily the screw that came with the GPS had a very flat head. I just drilled out enough for the head where the screwdriver mates to the screw to fit below. The thin part of the head still rests above the black. When you are done it should look something akin to the picture below.
The final step is to reassemble the entire thing. This step is pretty self explanatory. One thing that I found I had to worry about after it was too late was to grind the corners and all sharp bits off of the top plate. If you fail to do this it will gouge the GPS when attaching it. Below is what mine looked like as a final product.
For a final look here is the GPS on the mount installed on my camera.
Cable Construction
Now to construct the cable. This cable would be about $150 dollars and a 3-6 month wait should you buy one from Nikon. Even then you would still need a serial adapter for your GPS. This hack was harder than the first one for me because the 10 pin connector on the D200 is poorly documented. Well I am sure it is perfectly documented but that would require an NDA with Nikon. That is something I do not have. For a reference one what each pin on the 10 pin connector does I referenced this page. One caveat I found is that with the MC-21 cable I used the color coding on his chart is correct however if you are looking at the female connector the pin-out is a mirror image to what is shown there. It is for this reason I may still have one wire wrong. I do not know the long term implications of this and take no responsibility for what anyone decides to hook onto their camera. In actuality it seems that the communications between the camera and the GPS are only happening in one direction. I Think I may have the Rx for the GPS hooked to an unlabeled pin on his diagram. More on this later as it is neither here nor there at the moment. First lets take a look at what we need to make this hack work.
This little cable is a 5 volt serial converter. It can be found here. It is available in a 3 or 5 volt version. You will want to acquire the 5 volt version as that is what the D200 will provide for us. After shipping this item set me back $29.
This here was an e-bay special. This is a cigarette and serial adapter for a Garmin GPS. After all was said and done it set me back $16.25
This is the Nikon MC-21. It is a very spendy little cable. If you can find a source of a male 10 pin connector for the D200 for cheaper elsewhere I suggest you go for it. There are cables on E-bay that claim the are compatible. The however do not have the metal locking shoulder which is something that I really wanted. This spendy little item cost me about $70 after shipping. It was part of another order so I can write off some of the shipping.
The first step in making the cable is to remove the DB9 housing from the serial converter and remove the female DB9 connector. To do this there are two simple screws o the housing than need to be removed with small standard screwdriver. Removing the DB9 connector is a little more of a chore because of they way they attached it to the board. I must admit though that was pretty clever to slide the board in between the solder cups like that. Take a soldering iron and solder braid and remove all of the solder from each cup and pad on the connector. This ate through my braid but is absolutely necessary so as to do your best not to lift pads. I didn't do this too well and had to pick different solder points later. Below is a picture of the board sans housing and DB9 connector.
Next I shopped the connector off of the e-bay special. I left about 1.5" of cable to work with. I admit this is a simple step, but none the less the results are below.
Now I have no expectations as to how the color coding on any other GPS connector is so I will describe them with both the color in the photos AND the purpose. The black wire below is the ground, GND, from the GPS. I've connected it to the side of the capacitor shown at the top of the board because that pad is also a ground pad but is also a large pad. Larger pads are a lot harder to lift. (That is unless you are trying to remove a DB9 connector wedged on them) The red wire is the 5V+ line from the GPS. This wire is completely optional. I soldered it on for future if I would like to add a 5V regulator and power the GPS externally. If you notice the light green scratched near the black wire (GND) that is because I cut the extra trace that leads to the red wire (5v) that I soldered on. The trace appears to be for the upgraded serial converter that uses handshaking as well. If you connect the power wire from the GPS make sure to Isolate it from the circuit. The other two wires are as follows. The White wire is the GPS Rx. however since this serial converter was designed for use with a computer the lines are backwards from logical. I found this out after some staring at a data sheet for the national semiconductor part used on the board. The brown wire is obviously the GPS's TX then. This is the important wire to hook up in the right spot. I am pretty sure that the camera would still operate as it should with only the brown wire (Tx) and the black wire (GND). I think the Rx might be hooked to a wrong pin on the other side of the serial converter. At least it probably is according to the fore mentioned color coding. This should not be an issue because 1 it is a Rx line and 2 the pin on the camera is most likely a signal pin with a high impedance as all of the power's and grounds are accounted for.
This next part was figured out after several hours of monkeying with the adapter board on the inside of the MC-21 cable. First thing is first. If you want to be safe about cable lengths as I did I recommend using a long cable to make it all work and then cutting the 10 pin cable to the length you think you want it and re-attach it. If you want to go ahead and cut it as short at you think you need it now then by all means go right ahead. I just had the benefit of a female 10 pin connector on the end of my 10 pin cable. In this section I will go by the color coding found in the previously mentioned article. Also as I am sure different serial converters have different layouts for the TTL side connections this will be a little more difficult to explain. The purpose of this article is to make it easier for anyone else than it was for me so I will do my best. The green and yellow wires are the two grounds of the 10 pin connector. One is the signal ground which is the level that is considered 0 for logic levels. The other ground is the the ground for the power coming out of the camera. In order to have logical 0 be at the same level as the ground for the voltage plane the two must BOTH be connected to the ground on the serial converter. For this particular serial converter it is the second hole from the top of the picture. According to the color code the gray wire should be the regulated 5V. I however never saw a voltage on this wire. Id did however find the battery voltage on the brown wire. This is then what I used. The Vcc or 5V in to the Serial converter is the top hole according to the picture. If you have a different serial converter than the one I have shown then the easiest way to find it is to look up the part by using google to look up different numbers on the back of the package until you find a data sheet for the chip. follow the lines for Vcc and GND to the edge of the board on the TTL side and you will have where you need to connect all of these wire so far. Now for the signal wires. These two are seemingly backwards. In my case I had to hook the red wire from the Nikon which is supposedly Rx to the Tx of the serial converter. The Tx should be clearly marked on the serial converter. for mine there was a color code on the side of the cable. This leaves the Orange wire (Tx) from the Nikon connector to be connected to the Rx of the serial converter. I had to play with this wire a little bit. This is the one that I think that something may be amiss with. while the finished product works and Orange is labeled as Tx on the chart I found it to be in the position of Pin 5. Perhaps I Mixed it up in the middle of the night when I have time to work on this or that chart is wrong. Either way the orange wire seemed to be the one that worked.
At this point It should be a fully functional Unit. To give you an Idea of the size of my finished product below is a picture.
Now that I know its working and have tested it I gave it a good tight coating of electrical tape. Make sure you get onto the sheathing of the cables as to minimize any stress on the electrical connections inside. You can see my finished cable below.
Conclusion
Overall this project was fun and moderately challenging. I would say the hardest part was trying to make the serial converter work with the proprietary Nikon connector. Hopefully I saved you all that time. It took me about 45 minutes to make the mount and a several hours to make the cable. I would expect with directions the mount could be made in 30 minutes tops and the cable in about an hour or so. It depends largely on soldering iron skills and equipment.
Now to talk about the cost of this project. This is not the cheapest project in the world to undertake. However if you are looking to get a system it really is your best option. for the GPS I paid $99. For the Mount I paid a total of $14.50 as the screw I needed came with the GPS. The cable was the most expensive at $115.25. This cost could be reduced considerably if a cheaper 10 pin connecter is used. The grand total of the project is $228.75. Which for the same thing from Red Hen Systems retails for $544. This means I saved $255.25 by making my own setup.