The Ground Station
Due to the fact that I wanted my entire FPV setup to be small and compact, I opted to make the ground station an all-in-one package. I purchased a small aluminum case to not only house the screen, receiver and power system, but to also hold the camera and transmitter when not in use. The idea behind this, was that I could transport the entire FPV setup by placing everything in one box and taking it with me.
I started off with this aluminum case that I purchased from Harbor Freight. Its dimensions were 11.5" x 4.5" x 7.5"
The inside of the box was lined with a very thin type of foam that was partially glued down. It didn't look too good and seemed to peel very easily.
I made the decision to peel off the thin foam layer from the bottom half of the case, because that's where I would be mounting a lot of things. This, however, wasn't as easy as I thought it would be. After a few hours of trying everything (including acetone, soap water, power washing, rubbing alcohol and a dremel tool) I was able to scrounge away most of the foam from the bottom half. Unfortunately, it wasn't the prettiest thing in the world, but that was okay because I was going to be re-covering the entire thing anyways.
For the re-covering of the interior, I decided to use some balsa wood from Michael's. The wood was 3/16" x 3" x 36".
I cut different segments of various sizes so that I could neatly cover all 4 walls and the bottom side of the case. I found that Gorilla Glue was the best adhesive for this, as it allowed me a long amount of time to make adjustments before the glue set. Once set, however, it was very strong.
Next, I went ahead and repeated the process for the top lid. This time, however, I only removed the foam from the side walls of the top lid and then recovered them with balsa.
The last thing I wanted to do with the Balsa was create some dividers in the bottom of the case. I used two sections of Balsa to separate the bottom of the case into 3 sections. One for the antennas, one for the transmitter and camera and the last for the battery.
After this was completed, I moved on to prepping the screen. The screen I chose to use was a 7" car DVD player screen that I purchased on eBay for $20.
The screen had an AV IN port as well as a barrel jack for a power connector, but I wanted to remove the screen from the case and make some custom connections. I started off by prying the case apart and taking out the controller board.
I then desoldered the yellow AV IN port and replaced it with a servo lead which I soldered into the place - white is for video, black is for ground and red is for audio. I also went ahead and soldered in the battery leads into the VCC and GND through-holes. The three wires in the top left of the photo below are just the wires connecting the screen to the board. They were already soldered into place so I didn't have to make any modifications to them.
I then flipped the board over, inserted the ribbon cable, and stuck the entire board to the back side of the screen with double sided foam tape.
View from the front of the screen.
After the screen was complete, I moved on to preparing the RC305 receiver I was going to be using. The receiver, like the screen had an AV OUT port as well as a DC IN barrel jack.
I unscrewed the 4 screws that were holding in the two side plates then slid out the PCB. I then desoldered the AV IN port, just like I had done with the screen.
After that, I went ahead and soldered in the servo lead for the AV connection as well as a JST for the DC IN connection.
When that was complete, I slid the board back inside the case and screwed the two side plates into place.
The next step in the build was to build the housing that would situate the screen and the receiver. I decided to go with using black foam board from Michael's because it was the easiest to work with and offered the highest strength. I cut out a rectangular section of the board that would slide perfectly into the top lid. I then cut a screen-shaped hole out of the center of the foam board so that the screen would be able to sit in place.
Then I took my screen and tension fitted it into the rectangular hole I had cut. I lined it up so the front of the screen was flush with the foam board.
Next, I took some electrical tape and sealed the edges of the screen so that it could not fall out of the foam board.
After the screen was in place, I carefully placed my receiver near the edge of the board so that the antenna could be accessed from the top. I secured the receiver in place using double-sided foam tape.
The next thing I needed to do was create some sort of mechanism to hold the foam-board in place inside the top lid. I decided to use a magnetic mounting system because it was simple to make and easy enough to remove, if I ever needed to. I used a 0.5" x 0.5" Balsa stick that I got from Michaels, and embedded two magnets into it. I also cut a matching metal plate from some spare flashing I had laying around. The idea was that the magnetic balsa pieces would attract and hold onto the metal strips inside the case.
I took the metal strips and glued them to the edges of the back of the foam-board. I used electrical tape to seal them in place. I also went ahead and connected all the wiring for the receiver and screen.
Next, I lined everything up inside the lid of the case and then glued my two magnetic Balsa sections into place. One on the left and the other on the right.
I took the completed screen and slid it into the lid so that the magnets engaged the metal strips. I cut a small notch in the bottom left of the foam board to allow room for the power cables.
While I was inserting the screen into the top lid, I drilled out a small hole in the top left to allow space for the antenna to stick out.
Lastly, to finish up the ground station I took some foam I had from another case and used it to hold the antennas, camera pod and battery in the 3 compartments I had made earlier. I left the fourth corner of the case open for any wires and connectors I needed to carry with me.
And voila! After many hours of work, a finished and functioning FPV ground station.