Custom ROV For Senior Project


#1

Hi,
My name is Grant Kobes and my high school requires me to do a project that benefits someone. For my project, I am building a ROV for my local underfunded Water Treatment Facility. I have already started working and have bought most of the electronics and have encountered some problems. Also, I do like the System OpenROV has made but since I have to raise the money myself as well as donate the finished project I could not afford to buy the entire OpenROV system. Which has lead me into some problems. Here is the list of the parts I have bought already:
BeagleBone Black from Amazon
Tenda HomePlug P200 from Amazon
Arduino Mega AT2560 from Amazon
NTM 28 Prop Series Motors from Amazon
Turningy 35Amp ESC from Amazon
LiFePO4 batteries from OpenROV
Battery Charger from OpenROV
Tether from OpenROV
Battery Tubes Kit from OpenROV
Topside Interface Board from OpenROV
180 Fisheye Lens Webcam from Amazon
Jumper Wires Pins for Arduino from Amazon

My first problem is how do I wire the HomePlug to the Arduino? I have already taken the HomePlug apart. Can I even use a regular Arduino Mega? How do I wire the Arduino to the BeagleBone?


#2

@bossgivol,
Here is a link to the OpenROV 2.8 Controller Board schematics which you can use to determine how to connect the HomePlug to the Arduino Mega and how to connect the BBB to the Arduino Mega.

Since the Controller Board is a custom design that uses an Arduino 2560, you will probably have to figure out which pins to use on the Arduino Mega board that are presently used on the Controller Board.

Unless you are really good at understanding Arduino/BBB programming and understand how to read electrical schematics I would say that you would be better off buying one of the OpenROV 2.8 Controller Boards, which is currently on sale, instead of trying to reinvent the wheel.
Regards,
TCIII AVD


#3

Though i would love to, I don’t have $180 to spend on something I’m just going to giveaway. Which is why I’m trying to ask for help that no one seems to be helpful enough to even try and give.


#4

@bossgivol,
Since it is going to be donated to a public entity, it just might be tax deductible.

What you are asking of the membership here is very complex and is not a task that is normally pursued on this Forum. It might have been best to ask if support of this kind would be available prior to purchasing the hardware. Do you have any experience with the Arduino microprocessor family and boards and can you read electrical schematics? If not, you are going to have a tough time with this project.

I would ask your local junior college microprocessor course instructor or a knowledgeable student for help. Since it is a project to be donated to a public entity you might just get some free help.

Here are some links to discussion threads on this Forum where members attempted to do what you propose to do:
Arduino Mega & BBB
Calibrating ESCs
Arduino Cape PCB
BBB & Arduino Cape
Arduino Uno or Mega

If you are going to use the Arduino Mega 2560 Board then you will probably need a Shield to go on top of the Mega Board to get access to the Arduino 2560 Digital I/O and Analog I/O Channel pins as shown on the OpenROV 2.8 Schematic Cover Page.

The HomePlug Adapter on the ROV end and the BBB both get their power (+5 vdc and +3.3 vdc) from the Controller Board and I doubt that the Arduino Mega 2560 Board can supply the necessary current for the HomePlug Adaper (+3.3 vdc) and the BBB (+5 vdc) without possibly going into overload.

To connect the BBB to the HomePlug Adapter on the ROV end you will have to fabricate this OpenROV RJ45 Connector. The BBB will communicate serially with the Arduino Mega 2560 over the Arduino’s primary serial UART. The BBB communicates with the Topside Adapter/Laptop through the HomePlug Adapters via the Tether.

Also, unless you plan to duplicate the current and voltage measurement circuits on the Controller Board, you are going to have to extensively modify the Controller Board firmware which will be no easy task.

I am a Systems Engineer with over 30 years experience with Digital/Analog Control Systems and there is no way that I would tackle this project when the Controller Board solution is available due to having to ensure that you connect all of the off board components to the right pins of the Arduino Mega 2560 Board and have not made any mistakes which could be disastrous. You will need a good low wattage soldering iron and a Digital Multimeter for this project.

Regards,
TCIII AVD


#5

I really appreciate your help. The only other question I have now is what pins on the ROV HomePlug connect to the tether? (And which need power I guess)


#6

@bossgivol,
Your latest question can be answered by looking at the 2.8 Controller Board Input/Output Schematic. The HomePlug Adapter pin-outs are in the lower right hand corner of that schematic.

Here is an OpenROV Forum link to a teardown of the HomePlug Adapter. Unfortunately I believe that this teardown discussion thread is for the original v1.0 adapter and not the current v2.0 adapter that has pins and sockets for the board interconnections. Here is an additional link to an OpenROV Forum discussion thread concerning the v2.0 HomePlug Adapter. Also, do a search on the Forum for “HomePlug Adapter”.

Have you downloaded the 2.8 Controller Board Schematics yet? If not, then you need to use the link I gave you above to download the schematics and learn to read them as this is your project.

Regards,
TCIII AVD