Running 4 stepper motors at once

Projects Programming
1

Hey all! So this is my first post, I have browsed the forum and cant seem to find the guidance for exactly what im looking for. Heres the project and my goal.

Project is a 4 wheeled vehicle using omni directional wheels. Wheels are run off of stepper motors using an Arduino Mega and Sparkfun EasyDriver. I understand the basics of getting the steppers to run. What I need is to be able to run the 4 wheels at the same time and can't really figure out how to do this. Any help or functions to use to do this? I understand the Arduino programming somewhat but still a beginner.

Cheers

2

Do one step at a time. Then you can step the motors in any sequence in any direction.

Typically you will know how far you want to move the motors and which direction, then you want to adjust the timing so the motors all finish at the same time. You figure out which motor has the most steps and calculate how often each of the remaining three have to step to finish at the same time. A simple example would be where one motor has to step 1000 steps and the other three have to step 500 steps. On that one the math is easy: step the fast motor as fast as it can handle and step the other motors every other step (half the rate because they have half the steps to travel).

3

So basically set up a basic loop where each motor is stepped once (if going strait) then loop it continuously/I have it triggered by something to stop?

4

So you don't know how far you want to travel? You only know the relative speed of the four motors?

Create an array of four motor speeds. The fastest motor gets 1.0. The slower motors get their relative speed

Create an array of four accumulators. Set them all to 0.0.

Every time through loop():
compare the current time against the time of the previous step
it it is time to step again
Record the current time as the previous step time
for each of the four motors:
Add the motor's speed to the motor's accumulator
If the accumulator is >= 1.0, step that motor and subtract 1.0 from its accumulator

That's it. To stop, just set the four speeds to 0.0