Where I got my original idea to make the GPS interface to my camera for geocoding...



If you don't have any of the stuff listed here it may be a bit pricey project but if you have knowledge on how to make a pcb and you already have the pharos gps you are in luck. Of course you will try this at your own risk because, well this is just a document for your knowledge and I will NOT take any blame for what you may break (Like your expensive camera, gps or anything else for that matter).

I used the GPS unit that came with my Microsoft Street and Trips 2008. It is a Pharos GPS-500 sirf star III. The GPS works great is really accurate and locks down a signal in seconds. I love it and the price couldn't be any better. This GPS is currently out for about 60 bucks in stores and it comes with the GPS software for your pc and a usb adapter. I already had one so I didn't have the need to purchase one. I have seen used ones on ebay for around $20.00 with the btII bluetooth adapter. I used the connector on the old btI bluetooth adapter for my project.

Note: The reason for the female 10 pin connector, and 10 wires in the cable that is going to the camera is simply so that you can use another device at the same time. It will be a passthrough, nothing special is done to the circuit. Since other devices use different pins it should not interfere with the GPS unless of course you plug in another GPS while this one is on.

Here is what you will need

- GPS-500





- Pharos GPS case (optional)



- USB /bluetooth adapter just to steal the connector for the gps unit. (optional you could always solder straight onto your GPS which I don't recommend) I would try to get an extra one off ebay or something because you will have to make it useless unless you make your own adapter...

- max233acwp chip (you can get a free sample on the web just google "max233acwp free sample")

PDF for Max233 Chip I used



- Couple of thin wires

- A 2" X 3" X 1" project box



- Some soldering skills specially if you are going to use the surface mount

- Dremel or something to cut your pcb and drill the tiny holes for your components

- 1 x 1 microfarad cap

- (Optional) a small 3v led

- (Optional) a small switch

- (Optional) Nikon female 10 pin plug from an old camera. (I purchased one for $10.00 off a camera repair shop from a D1) Nikon 10 pin connector with a long lead off of ebay. Make sure all 10 cables are there. Most of these only have three cables. (This cable is hard to come by and expensive about $40.00 on ebay at the time)

- (Optional) you can get 10 header pins and 1 10 pin connector usually used for db9 ports on a computer to make it easy to plug in your components. If you don't do this you will need to solder everything straight onto the board.

That just about does it for the parts list. Fortunately for me all I needed was the project case, the Nikon Female connector, and the 10 pin cable. So this entire project cost me about 55.00. Not too bad considering similar receivers are currently over $200.00 for my camera. Again if you don't have half of this stuff it will probably be just under the cost of a real gps unit for your camera. I enjoy the challenge and I had most of the parts which is why I took on this project.

Steps to make the project

1. Download Eagle PCB 9 lite version cause it's free and works well.

2. Download my Schematic and PCB Design files.
(You may need to edit them to fit your project but it's a good start.)

Study the schematic and put it down on a breadboard for testing. Don't attempt to plug it in to your camera until you have tested and are positive that it is working correcly. Failure to do this could cause irreversable damage to your equipment. I tested the circuit on a breadboard using the db9 port on my computer with hyperterminal which is installed by default on any windows box. There is less chance to fry something on your camera if you do this. The pin 5 is GND, and pin 2 is your RX. That is all you need. You should see the output from the gps come out on your terminal window if eveything is working correctly.



3.Create your pcb (this is a lengthy process and there are many tutorials on youtube and google so I won't go over that here.

4. Drill your holes for your components, wires, and header pins. Plug in the components and solder them on to your PCB.

5. Open up your bt GPS dongle and carefully remove the connector for the GPS. It is very flimsy so careful not to overheat and melt the plastic. The use of desoldering braid will come in handy. It's about $3.00 at any local electronics store. Create the connector for your GPS with this and attach the +5v, Gnd, TX, and RX cables to a header female connector on the other end. If you don't know what I am talking about look at the gallery of pictures. I tried to be as detailed as possible there.
If you got yourself a female 10 pin connector you should solder a 4” cable to it and glue it with an epoxy to make it strong and keep all the wires insulated from each other.

6.Get the male 10 pin connector and put it through a hole in the box that you should drill. Then feed the cable through and connect it to the cables on the 10 pin female making sure that the pins match exactly on the male and female pins. Once you put them together put header female connector on it so that you may attach it to your pcb without soldering to it. (I know you are excited to plug this into your camera now but TEST ON HYPERTERMINAL FIRST!!!)

7. Place everything into your project box. Carefull not to break anything it will be tight in there. Make sure not to put anything directly in front of the GPS because this will cause you to have interference and will cause the GPS to take longer to lock or not lock at all.

8. Assuming it worked on Hyperterminal it should work on your camera so go ahead and try it.

See Pictures of the finished project here.

Things to watch out for

-Do not overheat the chip when soldering it! I had to use a new chip because when I put in the first one I messed up on one odf my solder points an I fried the chip. It was giving output but was intermitent.

-Make sure you have the pinout correct!!! Notice this pinout given above is the view from the front of a D300. The pinout should be the same for the D200 but I have not tested.

-The GPS does not do well indoors make sure when testing that you can try outdoors. I can get a GPS lock inside my house but it takes about 45 seconds where it takes an average of about 7 seconds to lock outside. Once it locks if I turn it off and turn it back on it locks in about 2 seconds.