Skywalker FPV Build - The Electronics

Electronics, Wiring, Ground Station and More

On this page you will find details and descriptions of the parts and accessories that have been included in my Skywalker build. I took many hours to research all the parts required for the build before I ordered anything, and this was probably the most time consuming part of the process. Everyone's build is a little bit different, and there are many choices of motors, batteries, ESC's, OSD's etc., out there to choose from. This was my first FPV build, so I probably made some errors along the way, but the end result is what counts! I hope some of these details and pictures can be some help to you as you may be assembling or thinking of your own.

Motor, Prop and ESC

There are a number of different popular power setups for the Skywalker, the Scorpion motor being one of the more expensive ones. I decided to work with a lower budget since this was my first FPV build. HobbyKing has a great motor that has plenty of power for my needs. I bought the NTM Propdrive 35-36 1400kv motor with prop adapter, which I paired with a Master Airscrew 9x6 prop. I chose the Turnigy Plush 60amp speed controller powered by a 3s 5000mah 20-30c battery. On my test flight I could cruise at a 1/4 power easily.

Remizibi OSD, Video and Accessories

The On-Screen-Display is an important part to a successful long range FPV platform. An OSD will overlay vital information in real-time on your display, such as GPS location, ground speed, altitude, battery voltage, and a home direction arrow. You can always estimate how long your battery should last, but seeing the voltage read-out in real-time is the best way to keep track of just how long you can fly.

Just like everything else, there are many choices when it comes to OSD's. They range from very simple to complex, comprehensive systems with return to home functionality. I decided to go with one that is kind of in the middle, the Remzibi OSD. This is a robust, full-featured OSD, with the capabilities to update and connect via USB to your computer as well. Once it's connected to your computer you can customize fonts, layout and configurations. It is priced around $120 and is a very flexible system. I've added a few extra cooling heat sinks to the board to help with cooling. You'll notice two small aluminum fin heat sinks as well as a small copper wire soldered to element that gets hottest.

In order to read the voltage of the motor battery, I needed a current sensor. I went with the Flytron 50 amp current sensor. This is a very small sensor that can read voltage levels from 2.7 to 40v. It already has the necessary .001 ohm sensor shunt and resistors install on the board. All I needed to do was solder the Dean's T-Plugs to the in and out of the board. This will intercept the connection between the battery and the ESC, giving a live read-out of the battery's voltage levels. After soldering the connectors onto the sensor, I covered it in black heat-shrink tubing for protection. I've also made an adapter to connect the Deans to a bullet connector, which my batteries use.

The camera I'm using for the live video feed is the 690TVL Ultra WDR Pixim SEAWOLF 2.8mm. The camera was originally purposed for a security camera, so I had to cut the stock connectors off and solder the wires into a standard servo plug. I did this for both the camera wires and the video transmitter connectors. I've also added a microphone to the VTx which is powered off of the same harness as the transmitter.

I chose to go with the LawMate 1.2GHz 1000mW  transmitter and the LawMate 1.2GH receiver. The solder points on the transmitter's board were weak on the unit I received, so I ended up resoldering them and securing them with a good amount of hot glue. I also have a Low Pass Filter for 1.3GHz Antennas attached to the Tx to stop interference of the 1.2ghz with the 2.4ghz band. The Tx is mounted on the rear tail section and the antenna will attach there as well.

Video Diversity

I've had around 10 FPV flights so far with my Skywalker, and I've used a single 8dbi patch receiver antenna each time. The patch antenna is great for long-range directional flights. It has a 70 degree FoV which covers a wide range in front of where it is pointing. There is a drawback to this however, for example if I fly behind or too far left/right of my antenna I will start to lose video signal.

There are a few remedies to this problem. I could change out my antenna to a circular polarized one giving me 360 degree coverage, but I will lose strength at a distance. I could add an antenna tracker, which will automatically point my patch antenna to where my plane is. This method can be very effective, but can be a bit costly and more complex. The third option, which I chose to go with, is video diversity. This is where you have multiple receiver antennas, often 2 different types, and then a diversity controller which chooses the best signal automatically out of the two antenna. This way I can have the best of both worlds, a circular polarized antennas for short range 360 degree coverage, and a long range patch antenna for further directional flights.

Some diversity controllers can be quite expensive, but there have been some newer types coming out as of late, and they are quite affordable. I purchased a Micro Diversity Controller from Range Video which takes two video inputs, chooses the best one based off of the RSSI signal strength, and outputs that video. It does all of this very quickly, so you won't even notice a dropout or switch happen.

I was using a 1280mhz Lawmate receiver, so I purchased a second identical one for the diversity setup. In order for the diversity controller to choose the correct signal, it needed to know via RSSI which receiver had the best reception. I had to open up the receivers, find the RSSI pin and then solder a wire to it and the metal case for a ground. I used a servo extension wire for easy linking/unlinking.

Inside the Skywalker

Since the start of this build I've added a few new components to the the Skywalker. I've added the FY-20A V2 flight stabilizer, and also a RMILEC LRS UHF system for long range control. Here you can see all the wires and components that make this thing work, Rx, OSD and Stabilizer.

The Ground Station

There are many ways to make a ground station for FPV, but I tend to like the "finished" look better than all the components just hanging out in the open. So I started with a cheap case from Habor Freight and started modifying it to fit my needs. The case has a top and bottom panel cut out of thin plywood and then covered in carbon fiber vinyl tape to give it a "techy" look. There are 4 switches, red being the master power switch and the other 3 will power individual components like the receiver, lcd screen, and transmitter. I am separating them to allow me to choose if I need them all powered or not, which will save some battery. (plus it looks cool)

I've cut out sections in the upper panel for the voltage meter and the 7" LCD screen. Three sections were cut out for the lower, the left for storage of the Fat Sharks, middle for access to the video splitter, and the right for the battery. The receiver and transmitter will sit underneath and will not have an access from the top, because once they're setup I won't really need to mess with them. The bottom panels also have doors that I made for them with small brass hinges and some knobs to open them.

 More to come...!

Make sure to check out the Skywalker FPV Build!