How To's

Controller Wiring for the "H" Bridge Relays


This is a basic Arcade Type Joystick assembly that you can use to control your Rov's Forward, Reverse, Left, and Right Movements. This is a digital joystick and control is accomplished with 4 simple snap switches that handle 4 relays, there is no need to use microcontrollers or even build any circuits for this hookup, just some more basic wiring.

This is what the 4 snap switches in your joystick should look like. You will be using the Com (common) and NO (normally open) poles, the NC (normally closed) poles will not be used during this hook up.

You will be mounting the Joystick assembly in your control box diagonal so when you push forward on the Stick the Joystick Control Block will press on two of the switches at the same time. When you press the stick forward the Block actually moves toward the rear switches, in these diagrams you are looking a the bottom of the joystick. You'll also notice that the Left and Right Reverse Switches are labeled backwards, this will become apparent later on in this write up.

The first step is to wire all of the Common Poles together.

The next step is to start connecting in your Tether wires from your Relays. (Below is the Relay diagram for reference.) For ease of my drawing I didn't draw the actual wires to running to each switch here so just connect A to A, B to B and so on. (For this step you are just connecting A thru D. for now.)

Power for the relays will depend on the relays you bought. If your relays are run from the same power source as your thrusters you may be able to tie in the common positive on the Rov from the main power feed instead of running a separate wire through the tether.


Then you will be using a Single Pole Double Throw Switch for Depth Control. You could use another joystick for this but I just showed a Switch for ease of drawing. If for some reason your Vertical Thruster runs the wrong way either change the two wires around or you can even flip the switch over in the control box.

Control of the light can be any kind of toggle or even a push button switch (just make sure its not the momentary type)

I drew this table to figure out which Relays need to be On when the Joystick was pressed in a certain direction. (Below is an explanation of what everything means.) Turning sort of has 2 speeds, if you press diagonal into the corners only one Thruster is turned On and your Rov should turn relatively slow in that direction. If you press true Left or Right one Thruster goes Forward while the other one goes in Reverse which will make your Rov turn faster or even spin in place depending on your Thruster positioning. You can also figure out from this table why the reverse switches are backwards.

This shows how to read the above Diagram - in the above example the Stick is Press Up/Forward which then moves the Joystick Block backwards and turns on the 2 bottoms switches (Forward Left & Forward Right Switches) This would turn on both the Left and Right Forward Relays which in turn would turn on both the Left and Right Thrusters and move the Rov forward.



As an alternative to the Joystick you could also use two S.P.D.T Switch for control. With this hook you basically dive the Rov like a Tank, I think the Joystick is a much better way and its easier to drive but I included this because S.P.D.T switches are readily available.

This table shows the switch positions for control using the duel switch setup.

If you have any other questions feel free to E-mail me, or if you actually use this setup let me know how it worked out for you.
All Information, Pictures, and Material is copyright © 1998-2009 by Stephen Thone and may not be used for any personal or commercial purposes without the consent of the author. All rights reserved. The Author makes no guarantees or warranties as to the accuracy or completeness of, or results to be obtained from accessing and using the Information herein.