FPV Quadrotor Flying

What is FPV Drone Flying?
Soldering and Assembling the Drone
Learning About the Components of a Drone
Troubleshooting the Drone
- Updating the firmware of the flight controller
- Getting the drone to "arm"
- Lipo Battery Care
- Solving excess heating of the VTX
- Connecting the goggles to the VTX
- Having clearer image quality from the VTX
- Adding a beeper to the drone

What is FPV Drone Flying?

Imagine a flying drone with four propellers zooming past hoops, trees, and buildings. Sometimes these drones are doing flips in the air and sharp corners. Behind the drone is someone with a giant remote control radio and first-person-view (FPV) googles. This person sees what the drone is seesing from a first-person perspective.

I wanted to get started in this hobby because it looked like something that was fun. At the same time, I learned a few skills such as soldering, using a multimeter, troubleshooting, and how to deal with fustration.

Doing this hobby requires one to have the patience to learn by themselves. I learned by watching information-packed or vauge tutorial videos or by reading poorly descripted electronic component manuals or online forums.

This hobby required me to either search for the answer online or to try different options in the software whenever something did not work. Things did not work most of the time, but my struggles paid off because now the drone is able to fly, which is rewarding to experience.

Even today, I am still trying to create a better flying experience by searching for new components to incorporate into my drone setup and troubleshooting problems along the way.

Soldering and Assembling the Drone

Assembling the drone required skills in soldering. I had a bit of experience in soldering, but this stage was like a test. I could not mess up because I purchased all the components that took weeks to ship to my home.

I had to watch videos on Youtube to learn how to solder correctly.

I learned how to solder components correctly without damaging the electronics. For example, having the soldering iron set to the melting temperature of the solder is important. This helps prevent too much heat from burning the electronics. I also learned about how to maintain the soldering iron in good condition by tinning the tip with solder before and after use. This step prevents oxidation of the iron.

The video by the YouTube channel UAV Features helped me get started in assembling the drone. This video was a good video. It helped people choose what electronic parts to purchase as well as showing how to assemble the drone. I followed the advice of the video and purchased the recommended parts. I also followed the instructions of the video. There was a problem though.

The trouble was that sometimes the video would not be clear in explanation, both in verbal and visual mediums. For example, when soldering the camera I had to double-check if I am soldering the higher voltage connection or the low voltage. Or when soldering pins on the flight controller, I had to research online the function of each pin.

This experience taught me how to be patient and problem-solve my way of assembling the drone.

I used this video as a starting point to get into the hobby. While it provided all of the necessary components to get started, it did not warn me of all the troubleshooting I had to do.

Learning About the Components of a Drone

Initially, I did not know what I bought. I bought what the video told me.

But, I got curious about how the drone worked, and I wanted to learn what each component does to make the drone fly.

Watching YouTube videos and looking at more websites like getFPV.com helped me understand the basic functions of each part.

Electronic Speed Controller
- These connect to the motors and drive the motors to spin.
Flight Controller
- The flight controller is like the brain of the drone. It communicates with the radio vs TX and RX and tells the electronic speed controllers how fast to move the motors.
- It also includes sometimes sensors like an accelerometer or GPS capability.
Power Distribution Board
- It connects to the battery and the flight controller. It provides power to all of the components.
TX vs RX
- TX stands for transmission
- RX stands for receiving

In addition to these components, I learned even the motors and the batteries have different ratings for different applications.

Soldering/Assembling My Drone

Troubleshooting the Drone

Updating the Firmware of the Flight Controller

One problem I had was making the motors spin fast enough to make the drone fly. The terminology is "arming" the drone. It took a few days for me to figure it out. I eventually learned that the drone motors have to first be recalibrated in the drone software, Betaflight.

Before that, I first had to figure out how to connect the drone to the software, and I tried many things that did not work. I tried downloading many drivers, following different video advice, and I could not figure it out. It took a few hours of troubleshooting.

It was a two-step solution. The first step was to reflash the firmware. The second step was a post on a forum saying not all USB cables are the same. Apparently, some USB cables transmit current and data, and some just transmit current. Switching the cable out fixed my problem of connecting the drone to the software. The solution was simple, but figuring it out and being patient took a lot of time and effort. It was one of the first hurdles I was glad to persist.

The first time I got the drone to fly

Getting the drone to "Arm"

Next was getting the drone to "arm". In the UAV features video, he said the drone should arm at a hit of a switch. I was excited because I spend a long time figuring how to correctly connect the parts and how to connect the software to the drone. Then, my motors did not spin. I checked multiple times my radio control settings and drone settings, but still, it did not arm. This process took another few days to figure out. Eventually, I found the solution was in the software. There is a tab that has a small interface. I had to change the settings for this.

Finally, I had the motors to arm; however, the motors did not spin at a high enough RPM. There was not enough thrust. When I would raise the throttle all the way, the drone would barely take off. Checking the recommended battery choice for the ESC and the Flight Controller, I knew my components were compatible.

This is when I learned from a Youtube video that the solution is to recalibrate the motors. I almost gave up at this point until I saw the video. Again, this took multiple days to figure out. The solutions are so simple, but figuring them out was hard. It was different for me compared to school. At the school, I have a textbook, a professor, and other classmates if I ever needed them for help. But with this hobby, the people I have to help me are people from the internet who create hidden gems of information.

But, I think struggling and problem-solving the solutions was worth it. Now, I have a drone that does fly.

LiPo Battery Care and Charging

Important Battery Specifications

I learned there is a proper way to charge LiPo batteries for quadcopters or in general.

A battery has different S ratings. My batteries are 4S. This means there are 4 cells wired in series. The more cells/larger the S rating, the higher the voltage of your battery.

The nominal rating of a cell is 3.7 Volts. A nominal rating of a 4S battery is 4 * 3.7 = 14.8 V

The full charge rating of a cell is 4.2 Volts. A full charge rating of a 4S battery is 16.8 V

The 4S batteries I use

Important specifications of the battery:

14.8 V is the nominal rating
65C is the discharge rating
1400 mAh is the capacity rating

A pack can provide Amps = C rating * Capacity

Charging and Storing Batteries

To charge the batteries the best method is to do balance charging. This means the charger will charge the batteries so one cell is not overcharged. If you do not do balance charging, the cell that first receives current can be overcharged beyond the 4.2 V. This can lead to fires.

The LiPo batteries are very fragile when it comes to how much they are discharged. Discharging them beyond 3.7 V will damage the battery. When storing them, it is best to store them at 3.7 V.

The range for a battery cell's condition:

3.5 - 3.7 V is considered bad for caring for the battery. 3.5 V is essentially a dead cell.
3.7 - 4.2 V is considered safe battery cell voltage. Storing it at 3.7 V is recommended.

For a 4S battery, the overall voltage:

3.5 V each cell - 14 V
3.6 V each cell - 14.4 V
3.7 V each cell - 14.8 V
4.0 V each cell - 16.0 V
4.2 V each cell - 16.8 V

Solving the Excess Heating of the TX Circuit

When I touched the circuit, it would always feel very hot. So hot I would avoid touching it at all cost. I double-checked the circuit connections and they were correct. So for a while, I just let it be.

I ended up searching if this is a crucial problem. Apparently, there were multiple voltage modes on the TX chip. I found this out by watching YouTube reviews and reading the manual for the receiver. I found the manual by looking on Google.

However, I know just learned that a high power mode is preferred for better video reception. So I guess it's a trade-off between overheating the circuit or having a clear FPV video feed.

Connecting my Goggles to the VTX

I also learned how to connect my FPV goggles to the video transmission component (VTX) on my drone. Apparently, there are standardized brands and channels the goggles and VTX use. Looking at the manuals for both pieces of equipment I was able to tune to matching frequencies.

Important information of the VTX

Specifications of the goggles

Having clearer image quality from the VTX

This is something I still need to work on. As of now, the camera feed is blown out with white and I cannot see anything. In addition, when I turn a corner the video becomes filled with static noise and I cannot operate the drone.

I have read that buying a circular polarizing antenna might help with this.

You can notice how blurry the video feed is from the FPV goggles

Adding a Beeper to Find My Drone

Some people add a beeper to their drone if they ever fly too far away and lose connection.

The beeper I installed is the Full Speed Lucky Box Buzzer. After the lipo battery of the quad discharges, the beeper will go off to help me locate my quad.

The Beeper Soldered to the Buzzer Pads

Configuring the Beeper mode in CleanFlight