Homebuilt Rov Forum

Exploring the Hobby of Building your own ROV - Imagine, Create, Inspire.
It is currently Jan 21st, 2018, 12:24 pm

All times are UTC - 5 hours [ DST ]




Post new topic Reply to topic  [ 10 posts ] 
Author Message
PostPosted: Jul 7th, 2016, 8:15 pm 
Offline

Joined: May 22nd, 2014, 3:02 pm
Posts: 11
Location: Nova Scotia, Canada
Hello everyone,

After a lot of reading and no actual experience with this, this is what I have come up with as the new digital controller design.

If you see anything please let me know.

Here is the system break down schematic.
Image


Top
 Profile  
 
PostPosted: Jul 15th, 2016, 5:50 pm 
Offline

Joined: Feb 28th, 2013, 6:01 pm
Posts: 383
Location: Australia
Saw you posted about a week ago and may have moved on in design by now. Anyway, there is no video connection shown, or were you hoping to get video through the Arduino? If so, the Uno lacks the processing power to do video, and the RS485 connection does not have the speed required for video. The Uno will be able to generate the OSD data however, depending on the OSD board.

Not familiar with that compass board, but I think that it will require tilt-compensation (from external accelerometer board) to operate in any practical sense.

Aside from that the layout looks OK. The PS2 shield and the H-bridge boards look interesting so I may check those out myself. Hope that helps.


Top
 Profile  
 
PostPosted: Jul 16th, 2016, 6:21 pm 
Offline

Joined: May 22nd, 2014, 3:02 pm
Posts: 11
Location: Nova Scotia, Canada
Thank you for answering.

I was hoping on using Cat5E-STP and piggy backing the video on pins 3 and 6 which are not used for the RS485 communications. . . if that is even possible?

I have not decided on a final camera yet, and for the moment am using a BOSCAM HD19 as I had one on hand, but I know it is ill-suited to the job.

The idea for the OSD came from this thread:
http://www.homebuiltrovs.com/rovforum/viewtopic.php?f=4&t=1533&hilit=osd

He used HobbyTronics Max7456 breakout for the OSD and a SparkFun triple axis magnetometer (I am trying to copy this exactly) for direction and I am assuming is compensated just from seeing what he has already worked out.

The motor drivers have been switched out already due to supply issues with the manufacturer, but I'll report back on the replacements when I get and test them.

I am new to the Arduino and programming in general so this will be an "adventure", but I really want to see this work.

I hindsight too both of my posts on this project are in the wrong sections, and should be under the newbie section as my background is mechanical systems and not electronics.


Top
 Profile  
 
PostPosted: Jul 17th, 2016, 5:33 pm 
Offline

Joined: Sep 11th, 2015, 2:31 am
Posts: 15
It is not compensed, you need a IMU.


Top
 Profile  
 
PostPosted: Jul 17th, 2016, 6:27 pm 
Offline

Joined: May 22nd, 2014, 3:02 pm
Posts: 11
Location: Nova Scotia, Canada
Thank you. Do you have any recommendations?


Top
 Profile  
 
PostPosted: Jul 17th, 2016, 7:09 pm 
Offline

Joined: May 22nd, 2014, 3:02 pm
Posts: 11
Location: Nova Scotia, Canada
So yeah we are adding in this for an IMU.

http://www.robotshop.com/ca/en/6-dof-gyro-accelerometer-imu-mpu6050.html


Top
 Profile  
 
PostPosted: Jul 18th, 2016, 1:55 am 
Offline

Joined: Sep 11th, 2015, 2:31 am
Posts: 15
I used all-in-one 10dof IMU, i think it is easier way for programming, 9dof is the same thing, for example mpu9150, not the mpu9250, because there aren't more programming example in web! ;)


Top
 Profile  
 
PostPosted: Jul 19th, 2016, 7:18 pm 
Offline

Joined: Feb 28th, 2013, 6:01 pm
Posts: 383
Location: Australia
Be sure to use video baluns to minimize noise pick up from the 485 lines. I have used this compass https://www.pololu.com/product/2127 and the library that I think is available from that page.


Top
 Profile  
 
PostPosted: Jul 20th, 2016, 8:30 pm 
Offline

Joined: May 22nd, 2014, 3:02 pm
Posts: 11
Location: Nova Scotia, Canada
For sure.

I have a noob question: what is the advantage of having more degrees-of-freedom (DOF)? I am not familiar with this term.

My background is aircraft mechanics and I don't think I have ever head this in reference to gyros (and if I did I forgot it).


Top
 Profile  
 
PostPosted: Jul 22nd, 2016, 3:46 am 
Offline

Joined: Sep 11th, 2015, 2:31 am
Posts: 15
I used this 10dof imu because i have it, but i use a library that shows degrees of pitch and roll, that i used to compensed the compass.


Top
 Profile  
 
Display posts from previous:  Sort by  
Post new topic Reply to topic  [ 10 posts ] 

All times are UTC - 5 hours [ DST ]


Who is online

Users browsing this forum: No registered users and 1 guest


You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot post attachments in this forum

Search for:
Jump to:  
Powered by phpBB® Forum Software © phpBB Group