By Michael Delaney
Being an avid quadcopter pilot, I often like to fly for friends and family. One of the coolest aspects of these devices is the live video camera attached to the front of the quad. This camera sends the video feed to a pair of goggles which allows the pilot to see as though they are sitting in the cockpit of the quadcopter. However, as I only own one pair of goggles, it’s not possible for others to watch the video feed as I fly the device.
At first, I considered buying a commercial monitor online, but most of the displays I found were quite expensive. So, rather than pay for a prebuilt design, I decided to build my own.
This post is derived from an earlier one I made on hackaday.io, you can find the original version at: https://hackaday.io/project/160893-diy-homemade-fpv-monitor.
This project is made possible by GitHub user
This project began with a simple goal, to build an inexpensive FPV monitor that could reliably be used to view 5.8GHz video transmissions from my FPV quadcopter, but it quickly became more than a weekend project.
The construction of the circuit was overall quite simple, a few connections between the Arduino, RX5808, and LCD screen was all that was needed to build a functional prototype.
After this early success, I decided to design a custom circuit board for the device. In the past, I have looked to Chinese facilities to help with manufacturing these designs; however, given the simplicity of the design, I decided to experiment with making my own using a laser engraver.
For my first attempt I coated a blank PCB with sharpie and then removed the coating off with the laser, but the final product had streaks of marker left on the board which prevented me from etching the board.
As a second attempt, I coated the copper circuit board in a layer of spray paint. This time the laser did a much better job of removing the coating and the design looked great.
Now that the design was transferred onto the circuit board, I needed to remove the copper material from the surface.
Working at home, I etched the circuit board using a few common household ingredients: hydrogen peroxide, vinegar, and salt. This process, while much safer than commonly used etchants like ferric chloride, takes quite a bit of time. Unfortunately, by the time the board was nearing completion, the paint had begun to peel off the circuit board.
In my third attempt, I decided to try again using a stronger adhesive. This was much more successful, and here is a video of the laser engraver removing the UV sensitive resin to transfer the circuit design:
With the design now transferred to the board, I placed the PCB in a UV chamber to harden the resin before placing the board in the etchant solution.
After 8 hours in the etching solution, I used acetone to remove the UV resin in the areas where I would be attaching components and started to assemble the circuit. I also had to drill the necessary holes for mounting the “through-hole” components.
Once the copper is etched and the holes drilled, I attached the components to the circuit board.
After the circuit was assembled, I connected the Arduino to my computer, and the screen came to life— mirroring the drone’s video feed.
But I couldn’t just leave it there… I used the laser engraver to fabricate a custom enclosure to house the electronics and battery.
The result is an elegant and useful FPV monitor, built for under $40, that I now bring with me whenever I fly my quadcopter.