In my last post “Get your hardware for Arduino Underwater ROV” I described most of the hardware I am using to build Alioli ROV and how I plan to use it. In this post, I will show how the hardware interconnects with each other and the boards I have built.

During the process of building Alioli ROV y when through several changes, most of them because I learned from the experience and improved the process of soldering and implementing boards. In the latest integrations, I started building my own boards because it made it easier to keep the table clean and made it more comfortable since I don’t have so many cables on my table.

The brain

The mainboard for the Alioli ROV is an Arduino Mega 2560 R3:

Power supply

The power I will need for Alioli ROV is:

• Arduino works at 5V
• Motors work at 12V
• Clock and some sensors work at 5V
• After getting the gyroscope and pressure sensors I found out that they work at 3.3V.

The maximum voltage I need is 12V (motors) so I am using a Voltage Stabilizer from 12V to 5V (HW-638) and a Voltage Converter from 5V to 3.3V. Motors will get their power straight from the battery since all the rest of the system will get their power from the Voltage Stabilizer. In this way, I am protecting the circuit from the noise of the motors when they start and stop. After the voltage stabilizer, it will be a Reducer Regulator Module from 5V to 3.3V to provide 3.3V to any circuit that needs it.

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I decide to build 2 boards: the first one is to reuse the Arduino Power Supply Module from the kit I bought so it provides me with several pins at the same voltage level and I am also able to use the switch to power on and off during tests, the second board is the one I will use when all the testing phase finish.

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I²C + RS485 board

Many of my modules work with I2C and because of that, I decided to make a board just for all of those, in addition, I thought it was a good idea to attach also the RS485 communication board for making compacter the final result. To build this board I used wires (30AWG 0.05mm²) with a silicone cover which made it easier to solder and manage. Some of the sensors do work at 3.3V so I have used a level converter to communicate 3.3V sensors with the rest of the bus at 5.5V (you can learn more about level shifter here “How a Bidirectional Logic Level Converter works? Logic Level Shifter“). WARNING: watch out, SDA & SCL are in different colors to show different bus voltages:

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Next post

During these days I will get Prototype Boards for Arduino Mega 2560 R3 so I can prepare buses and tests everything with the existing software. In the next post, I will publish the rest of the hardware that I have been working on and I will interconnect everything, the “Learn how to Build an Engine Controller for your Alioli Submarine UAV Drone“.