hardware requirements

Projects General Guidance
1

Hi,

I am building a 3m fully operational model submarine and i need to control 8 servos or 8 stepper motors.

What arduino board would be the most suitable and what other hardware would I need. I have got heaps of room so size is not a problem. Also if more than 1 board is required that also is not a problem.

I will wory about the programming once I sort out my hardware.

Thanks
Henry

2

There is a big difference between the control of hobby servos and stepper motors. Servos only need one control signal from the Arduino so any board should be capable of controlling 8 of them. And they have all their electronics inside them.

Stepper motors need stepper motor drivers and at least one limit switch each to allow the Arduino to send the motor to the HOME position. Then, the type of stepper driver will determine whether each motor needs or 2 Arduino connections.

You should also be aware that stepper motors are very inefficient and are not well suited to battery power.

...R
Stepper Motor Basics
Simple Stepper Code

3

Spend a few hours looking at ROV (remotely operated vehicle) youtube videos and forum posts to see what hardware people use.

You basically have a choice of dry motors with magnetic through hull couplings to transfer the torque to the propellers/rudders or wet motors like those used for submersible pond pumps which will need electrical pass though hull fittings which can be a world of pain.

Either way you are going to need a driver board for each motor to suit the motor type whether it be AC, DC, or BLDC. If I were building a 3 meter long sub I would use one Arduino per motor so that an entire motor assembly can be developed and tested in isolation before being installed.

4

mikb55:
You basically have a choice of dry motors with magnetic through hull couplings to transfer the torque to the propellers/rudders or wet motors like those used for submersible pond pumps which will need electrical pass though hull fittings which can be a world of pain.

I assumed the motor would be inside and dry with the propshaft going through a gland like on a full size boat. Isn't that practical?

...R