Ned Help ROV(submarine) microcontrollers/parts

roarroar

Hello everyone I am new in this forum

I hope someone can help me

I Have make a ROV(submarine),with 4 Thrusters.

My question is how can a control my 4 Thrusters on my rov (submarine)?

I think I will use 100m cable, 4 motors controllers (Parallax HB-25 Motor Controllers) and 2 Analog Joystick (from this site http://www.happcontrols.com/joysticks/50274000.htm)
but what microcontrollers can i use and what other parts do I need to control my 4 Thrusters on my rov (submarine)?


I have never use a microcontrollers, sow I need one that easy to use like BASIC Stamp.

Mike Green

You could use just about any Stamp although I'd recommend a BS2p or BS2px because of some of the extra statements and storage.
The Stamp can read the joystick directly using its RCTIME statement (read the description in the manual). The HB-25 motor controllers
have the advantage of only requiring a single control pulse to set its speed and direction and it will maintain that until it receives another
control pulse. With ordinary servos, the Stamp would have to produce a pulse for each of the 4 motors every 20ms. This is possible, but
it constrains the programming.

You didn't say what would be sent down the 100m cable, whether it would just be control signals or control and power. You will need
some signal conditioning and drivers / receivers for whatever signals go back and forth. What did you plan to have in the ROV itself?
If you're going to have batteries in the ROV, then you probably want a Stamp in the ROV and in the controller and have some timeouts
so the ROV can try to surface if there's a communications failure.

roarroar

ok, thanks! Mike Green

I will have batteries in the ROV, I need only 100m cable to signals go back and forth to the rov and surface (such as a RC control)

Sow I need one Stamp in the rov and one on surface?

can I connect 100m cable from Stamp in the rov to Stamp on The surface through RS485 or RS232 OR?

I Don`t understand.

Sow I wonder what do i need?

please! help me before i buy something from parallax.com

Post Edited (roarroar) : 12/10/2007 3:56:00 PM GMT

Mike Green

If you need to save money, something as simple as a Stamp 1 Project Board (www.parallax.com/Store/Microcontrollers/BASICStampDevelopmentBoards/tabid/137/CategoryID/12/List/0/SortField/0/Level/a/ProductID/119/Default.aspx) at each end would work, but very simply because the Stamp 1 has limited program memory and speed. It could read each of the 4 joystick pots and send their values serially to the ROV. The ROV would just wait for the next set of values and set the HB-25s accordingly. If communication failed, the ROV Stamp would "hang up" waiting for serial data and the HB-25 would time-out after 4 seconds. My assumption is that the surface unit would send a set of values perhaps 10-20 times a second to the ROV

If you want fancier control, you would need a Stamp 2 (BS2 or BS2p) at each end. These are faster and can have larger and more complex programs. You would need to build your own board or use the Stamp 2 Carrier (www.parallax.com/Store/Microcontrollers/BASICStampDevelopmentBoards/tabid/137/CategoryID/12/List/0/SortField/0/Level/a/ProductID/121/Default.aspx) along with the Stamp itself.

In either case, you will need to use either RS232 or RS485 for communication. For RS232, you will need to use a signal converter like the MAX232 at each end. For RS485, there are similar drivers. Look at the datasheets and application notes for these devices for sample circuits.

I suggest you think out what you want these controllers to do. If it's simply to communicate the joystick position to the ROV, the Stamp 1's should work and they're cheap. If it's anything fancier or you want to allow for more complexity in the future, you want a Stamp 2.