I am pretty new to electronics and have decided to tackle the MIT Sea Perch ROV. I've altered the design a bit. It calls for 3 motors and one of them (the vertical control) uses an SPDT push button switch which allows for the motor to reverse itself. I really like this idea and am attempting to alter the design to use 4 more SPDT switches for turning and forward/reverse.
What I've done is I've designed the control box to sort of emulate an old NES controller. What would be the D-pad is 4 SPDT switches and it is here that I am having trouble. Forward, reverse, and turning on the Sea Perch is done via two 12v motors at an angle. Just powering one will rotate the Sea Perch and giving power to both will let it move forward. What I'm trying to do is have these 4 SPDT switches control the forward, reverse, and rotation. Here is what I am after:
"Up" will power two motors and move the Sea Perch forward
"Left" will power one motor and rotate the Sea Perch left
"Right" will power the other motor and rotate the Sea Perch right
"Down" will reverse the power to the two motors and allow the Sea Perch to back up
I've got the first 3 to work via diodes but I am unable to figure out how to wire my "down" so it will do what I want. Right now it does nothing. This is my first attempt at such a thing and my first time making a post like this so I apologize if I don't show everything necessary for help. But I'll give it a shot.
I have my GND, PWR, and ACC wired for my left and right rotations. From my ACC I have my positive lines going to the motors. The lines from these ACC terminals have diodes to prevent feedback. I also have the positives for both motors on the "up" button on the ACC terminal. These also go through diodes to prevent feedback. On my "down" button, I have the negative for both motors in an attempt to allow it to work in reverse. What I figure is that the diodes are preventing the negative signal from being used through the "positive" lines to the motors so it won't allow it to spin the other way. But for the life of me I can't figure out a way around this. I have the feeling that the solution is staring me in the face but I'm just ignorant enough to not be able to see it.
Any advice/help would be greatly appreciated.
What I've done is I've designed the control box to sort of emulate an old NES controller. What would be the D-pad is 4 SPDT switches and it is here that I am having trouble. Forward, reverse, and turning on the Sea Perch is done via two 12v motors at an angle. Just powering one will rotate the Sea Perch and giving power to both will let it move forward. What I'm trying to do is have these 4 SPDT switches control the forward, reverse, and rotation. Here is what I am after:
"Up" will power two motors and move the Sea Perch forward
"Left" will power one motor and rotate the Sea Perch left
"Right" will power the other motor and rotate the Sea Perch right
"Down" will reverse the power to the two motors and allow the Sea Perch to back up
I've got the first 3 to work via diodes but I am unable to figure out how to wire my "down" so it will do what I want. Right now it does nothing. This is my first attempt at such a thing and my first time making a post like this so I apologize if I don't show everything necessary for help. But I'll give it a shot.
I have my GND, PWR, and ACC wired for my left and right rotations. From my ACC I have my positive lines going to the motors. The lines from these ACC terminals have diodes to prevent feedback. I also have the positives for both motors on the "up" button on the ACC terminal. These also go through diodes to prevent feedback. On my "down" button, I have the negative for both motors in an attempt to allow it to work in reverse. What I figure is that the diodes are preventing the negative signal from being used through the "positive" lines to the motors so it won't allow it to spin the other way. But for the life of me I can't figure out a way around this. I have the feeling that the solution is staring me in the face but I'm just ignorant enough to not be able to see it.
Any advice/help would be greatly appreciated.