swerve drive with arduino mega 2560

[Mike Bortfeldt]

Becky,

First off, I think this drive system is an great choice for a first swerve system. Having the steering modules linked together, as well as speed, will make things much easier from a control aspect. Because of this, I wouldn't start with any sensors. They are not needed to be able to drive around, and for someone relatively new to programming, this will make things much easier. I would use a two axis joystick model, where the forward/backwards motion drives the robot, and the side to side motion controls the speed of turning. Sensors can be added later once you get it driving if you want to have more (or more interesting) control.

As others have said, you will need to be able to generate PWM signals for the speed controllers and the Arduino servo library has that capability. But before we get to that, one important question comes to mind. Have you thought about how you are going to control this? What type of operater station do you have and how will it communicate with the Mega? Wireless? Wired (tethered?) Somehow you will need to get the information to the mega on what you want it to do, and that will add another layer of complexity to your system depending on the communications you want to use.

I would initially like to suggest an idea that could make this project much easier (no programming). Do you have access to an RC style transmitter/receiver? Maybe something like this? Using an RC style controller would allow you to eliminate the mega and just control the speed controllers directly. IIRC, the talons should be able to take a standard servo style input. Just a thought. There may be other better ideas out there, but this happened to come to mind. Would this be a possibility?

Mike

[asid61]

Originally Posted by Mike Bortfeldt

Becky,

First off, I think this drive system is an great choice for a first swerve system. Having the steering modules linked together, as well as speed, will make things much easier from a control aspect. Because of this, I wouldn't start with any sensors. They are not needed to be able to drive around, and for someone relatively new to programming, this will make things much easier. I would use a two axis joystick model, where the forward/backwards motion drives the robot, and the side to side motion controls the speed of turning. Sensors can be added later once you get it driving if you want to have more (or more interesting) control.

As others have said, you will need to be able to generate PWM signals for the speed controllers and the Arduino servo library has that capability. But before we get to that, one important question comes to mind. Have you thought about how you are going to control this? What type of operater station do you have and how will it communicate with the Mega? Wireless? Wired (tethered?) Somehow you will need to get the information to the mega on what you want it to do, and that will add another layer of complexity to your system depending on the communications you want to use.

I would initially like to suggest an idea that could make this project much easier (no programming). Do you have access to an RC style transmitter/receiver? Maybe something like this? Using an RC style controller would allow you to eliminate the mega and just control the speed controllers directly. IIRC, the talons should be able to take a standard servo style input. Just a thought. There may be other better ideas out there, but this happened to come to mind. Would this be a possibility?

Mike

For a swerve drive I would think manipulating motors directly would be difficult. It could be possible with crab drive. However, the Mega has a pulseIn() function one can use to read the PWM coming out of an RC transmitter, so perhaps that could be used instead of a wifi link or something for controls.

[ajlapp]

What type of operater station do you have and how will it communicate with the Mega? Wireless? Wired (tethered?

I've been slowly walking her towards these next steps.

Our free RobotOpen library and driver station will make tele-operation via wifi dead simple once she gets there. RC is an option too, but why not use the stuff designed for Arduino.

http://www.team221.com/robotopen/index.html

I think she can run this thing in autonomous only mode as well...she never mentioned needing tele-operation.

[beckster1999]

i would like to make it so that it is possible to drive it with sensors or a remote, as in have them both as an option. but im not sure how to put either a sensor or connect a remote to it. for me, the steps are really the things I need the most help with

[beckster1999]

also, im not sure what kind of sensor i should use

[beckster1999]

im going to use four IR sensors; one in each direction

[ajlapp]

Before this project gets all the way off the rails let's just keep making some forward progress.

The very next step you need to accomplish is to get the speed controller spinning the motor using commands from the Arduino. The "Servo" example is a good starting point.

Start there and see if you can get any action.

[beckster1999]

I cant find it.... also, i can talk at most points but I can only work on it from about 10-11 each day with maybe half an hour to an hour difference in when, but still only an hour of work

[ajlapp]

In the Arduino IDE

File->examples->servo

[beckster1999]

it's not there

[beckster1999]

it has servo mood indicator

[ajlapp]

make sure you have the newest IDE installed....I'm using 1.6.9...servo is under "examples" near the bottom.