In my last post, “Alioli ROV Boards“, I described most of the hardware I use to build Alioli ROV and how I plan to use it. In this post, I show how the UAV submarine hardware and electronics interconnect with each other and the boards I have built for that purpose: the engines, driver, board, and motherboard.

Engines driver board

I used an odd version of the engine board earlier, so I decided to redesign it again using my recently acquired knowledge and experience. Here is the schema for the new board:

The building process wasn’t easy because I decided to add logic to get an inverted signal for Ox signals (pink), inverting the signal given from the Ix signals (yellow) in the L298N Dual H Bridge controller. I also decided to explore the transistors (2 different kinds) included in my Arduino starter kit. Finally, I got to the conclusion that I had in my hand 2 NPN Transistors (models PN2222A and S8050). The good news was that the same logic applied equally to both.

After reading theory, asking friends from Telecommunications (you must know that I am a computer engineer and I didn’t have much idea about electronics when I started with the submarine), and making some tests on the protoboard, I got to these conclusions:

The next step was to build the board (first, I had to look for a bigger one since I couldn’t match the 3 L298 inside the boards I already had). I implemented the schema shown before. Here you have the building process:

Motherboard

The motherboard is where all the buses will interconnect with Arduino. For this purpose, I bought a Breakout board for Arduino Mega 2560 Rev3 where I could solder pins to connect buses and wire everything as I expect:

Then I started soldering on it:

Following the next schema:

And I got this as a result:

Finally the test

Then I connected everything, and it was working as I expected:

The next video shows everything working as expected. There will be a warning at the beginning saying that MPU6050 is not connected (yes, it is right, I changed it for BNO055 from Bosh). The video also shows the test for engines (usually, I have disabled this test), but I enabled it for the video to show that the driver board for the engines is working perfectly. During the test, each engine will rotate forward and backwards. After the engines, Alioli will say hello, doing a dance flashing red and green lights in a specific way.

Next post

We are ready to discuss the software framework I have worked on, the “Alioli UAV Submarine Drone Software Framework for Arduino”.