FPV Lunchbox -Ground Station-

So, like most of the FPV enthusiasts, I've been through the trouble of having to carry everywhere I want to go fly, a separate LCD screen, the video Receiver, batteries for the ground station, connecting cables and over that, having to find a good place to lay all that down.

I drew inspiration from the "suitcase" concept many people used for their ground stations, and started thinking about plywood boxes and a lot of non-sense, and don't know from where, the idea of a kids lunch box came, thus the concept was born.

 My ground station had to:

-Be dirty Cheap.
-Be tripod mountable.
-Fit inside a regular sized backpack.
-Hold a LCD screen, for spectators.
-Have a plug for my Fatshark goggles.
-Be rather plug-n-play, so I could eventually replace the receiver with a different frequency system. (I'm using 900mhz for the moment)
-Be cheap (can I stress it enough?).


So lets get on with the build!



I picked up a plastic kids lunch box from a local store for about $5. I selected one that had some sturdy plastic as I was to mount some components to it. The plastic on this one is 2mm thick.

 

The strap was removed as I wasn't intending on hanging it from my shoulder.

I then went to some local electronics store and picked up 2 toggle switches, and a RCA port. All the extra components I would need.

I used two switches. One to cut the whole power to the ground station and one to turn on and off the LCD monitor. This way I can use my Fatshark goggles with the unit, without having the LCD on at all times.



I started off by taking apart my LCD screen, as that was the biggest part of the ground station. I eliminated anything that wasn't extrictly necessary.

I marked a window on the lunchbox a few mm smaller than the actual LCD screen so I had some edge to attach to.

 

The piece was cut out with an X-Acto knife.

I also took apart the video receiver to save some more space. The video receiver is made up of a receiver module and a board.

 

Removing the casing freed up quite some space, but then I noticed the two transistors (regulators?) on the back of the board, which touched up on the aluminum case acting as a heat sink, so I left the bottom piece on.

 The receiver module is held in place by a nut that screws on the thread of the antenna port. This makes it very handy to mount on the ground station. A hole was drilled to be snug with the antenna port.



The next two holes to make where the ones for the switches and the RCA port.
I decided to put the toggle switches one on top of the other height-wise and the RCA port just below those.

At this stage I also decided to make the top switch (the closest to the LCD) the LCD switch and the bottom one the main power.



Last but not least, I drilled the hole for the tripod plate bolt. All of the cheap type tripods have a 1/4" hole on the plate with a screw you can replace. Notice the smaller hole to the side, which is for that little locking pin many tripod plates have.

 

Testing the tripod mount plate. Should have gone with a shorter bolt, but that's what I had laying around.

 

All the components test mounted. 

 

The whole setup as It will look when finished. The LCD is being held by duck tape at this point :P. No wiring or anything.

Now is time for spray painting! 

(You thought I would take out that cute, green thing?)

I had some cans of matte black, glossy black and a silver one. I love the matte black finish, but then I realized that, living in a caribbean country (Dominican Republic), where the sun shines the whole year, the ground station would get quite hot from exposing it, so I went with the most reflective one, the silver.

I removed the handle and the locking tabs and painted those black separately.

 

Yes, the black parts have quite some silver spots on them. I didn't pay too much attention to painting (as I should) because I was too excited to finish this project and put it to work.

A glossy white paint would have looked fantastic, but then again, I was going for cheapness.



After painting, and not letting it fully dry, I started assembling.



The LCD was simply hot-glued to the lunchbox. It makes it quite easy and sturdy.

I had to change the LCD monitor for a new (used one) as I killed the first one by powering it wrong (negative and positive reversed).

Despite triple checking the connections, I used a battery plug that was laying around my desk which had the leads wired the wrong way (The black lead was actually the positive). And also, the first LCD monitor was very crappy and didn't even have a safety diode :/.

 

I screwed on the receiver module to it's position, but didn't feel comfortable with it being supported only by the nut and the antenna port, so I took some spare foam board (left over from airplane builds!) and stacked a couple pieces together to make a base, which I hot glued the module to.



The board part and casing was also hot glued to the bottom of the lunchbox, with only enough space to clear the nut from the tripod mount and not to touch the receiver module too much (to prevent any shorting).



All electronic connections where made separately before mounting. The leads from the battery plug go into the first toggle switch, which on the ON position powers the video receiver and the second toggle switch, which then relays power to the LCD monitor.



Everything was mounted on its corresponding hole. I had it so, the switch would be turned ON when toggled towards the handle of the lunch box.

I used some old A/V cables I didn't throw out, and cut off the RCA leads. I used a Y splitter to wire one to my LCD monitor and the other to the RCA port on the outside. Again, I did it this way to make the whole receiver unit replaceable.

 

The wires coming from the other RCA lead were soldered directly to the LCD monitor PCB. Everything on the LCD side was secured with a combination of cable ties, double sided foam tape and hot glue.


The only thing left to do, was to tidy up the interior a bit.



I used some left over foam board to protect and cover all the wiring and everything, although I ended up having to make a window when I realized I wasn't going to be able to change channels or anything.

The only thing coming out are the battery leads and the cables to the LCD monitor.



On the LCD monitor side, I got lazy and only layered it with some soft foam sheets. I left the little adjusting board out so I could adjust brightness and such if needed.



Finally it's done



Mounted on the tripod.



Antenna screws in.



You only need to plug in a 3S LiPo. It will get connected and disconnected through the toggle switch, so no need to open the ground station up every time you wan to turn it on. (Although I do plug out the battery when I throw the unit into a backpack as the toggle switches like to get turned on in there.)



I have to say I'm incredibly happy with the out come. It solved my problem pretty good, and it turned out very nice, handy to carry, easy to operate, and of course, VERY cheap.

I hope this serves as an inspiration for someone out there! This is quite easy to build, and very practical.

Thanks a be safe!



Over and out!