Axis help

Programming Support
#1

Hey guys so I am building a six motor drivetrain and I need help coding my joysticks since I can’t create a drivetrain like you can with four motor. How am I able to code tank drive in python for a six motor drivetrain. Thanks

1 Like
#2

We just need the joysticks to function like a normal tank drive

#3

Yes you can, just not in the graphical configuration menu – create a motor group for the wheels on each side, then set up the drivetrain passing the motor groups in place of motors.

3 Likes
#4

I did that, I think I might have a solution but give me a sec and I will post the code

#5

I am unable to test this currently so will this work

# drivetrain functions

def drivetrain_left_forward():
    LF.spin(FORWARD)
    LM.spin(REVERSE)
    LB.spin(FORWARD)

def drivetrain_left_reverse():
    LF.spin(REVERSE)
    LM.spin(FORWARD)
    LB.spin(REVERSE)

def drivetrain_right_forward():
    RF.spin(FORWARD)
    RM.spin(REVERSE)
    RB.spin(FORWARD)

def drivetrain_right_reverse():
    RF.spin(REVERSE)
    RM.spin(FORWARD)
    RB.spin(REVERSE)

def drivetrain_stop():
    LF.stop()
    LM.stop()
    LB.stop()
    RF.stop()
    RM.stop()
    RB.stop()

# fourbar functions

def fourbar_up():
    FOURBAR.spin(FORWARD)

def fourbar_down():
    FOURBAR.spin(REVERSE)

def fourbar_stop():
    FOURBAR.stop()

# 4bar clamp functions

def fbclamp_clamp():
    FBCLAMP.set(True)

def fbclamp_unclamp():
    FBCLAMP.set(False)

# conveyor functions

def conveyor_forward():
    CONVEYOR.spin(FORWARD)

def conveyor_reverse():
    CONVEYOR.spin(REVERSE)

def conveyor_stop():
    CONVEYOR.stop()

# clamp functions

def clamp_clamp():
    CLAMP.set(True)

def clamp_unclamp():
    CLAMP.set(False)


if controller_1.axis2.position(100)
else drivetrain_right_forward()

if controller_1.axis3.position(100)
else drivetrain_left_forward()

if controller_1.axis2.position(-100)
else drivetrain_right_reverse()

if controller_1.axis3.position(-100)
else drivetrain_left_reverse()

if controller_1.axis2.postion(0)
else drivetrain_stop()

if controller_1.axis3.position(0)
else drivetrain_stop
#6

essentially does the drive code function as a tank drive

#7

this is C++, but you should be able to do something like this in python, it just takes the axis values and sets them to the motor speed. (fwd- forward, pct - percent)

     Right.spin(vex::directionType::fwd, Controller1.Axis2.value(), vex::velocityUnits::pct);
      Right2.spin(vex::directionType::fwd, Controller1.Axis2.value(), vex::velocityUnits::pct);
      Right3.spin(vex::directionType::fwd, Controller1.Axis2.value(), vex::velocityUnits::pct);
      Left.spin(vex::directionType::fwd, Controller1.Axis3.value() , vex::velocityUnits::pct);
      Left2.spin(vex::directionType::fwd, Controller1.Axis3.value() , vex::velocityUnits::pct);
      Left3.spin(vex::directionType::fwd, Controller1.Axis3.value(), vex::velocityUnits::pct);
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#8

You can also utilize the Vex Drivetrain with 6 motors.

#9

Ok so based on this I think the python version I made will work

#10

what you have is a little flawed, because you can only go at 100% or zero, and your if statements contradict each other making the robot go back and forth at a REALLY fast rate if the controller is at an axis value of -100 < x > 100 and x != 0

#11

But with it like this how do I make it go a certain distance

#12

Ok I will make the change then repost

#13

if you want to go certain distances, you might want to do a spin for command, because it uses the internal encoders to track how many rotations or degrees the motor has turned

#14

This is probably not correct but maybe.

if controller_1.axis2.position(100>x<-100)
else drivetrain_right_forward()

if controller_1.axis3.position(100>x<-100)
else drivetrain_left_forward()

if controller_1.axis2.position(-100>x<100)
else drivetrain_right_reverse()

if controller_1.axis3.position(-100>x<100)
else drivetrain_left_reverse()

if controller_1.axis2.postion(0)
else drivetrain_stop()

if controller_1.axis3.position(0)
else drivetrain_stop
#15

Is there a good way to convert that to inches based on rpm

#16

Or should I just guestimate and improve

#17

yes, the distance = circumference of wheel * amount of rotations

#18

Thanks that will make auton much easier

#19

Now I just need to know if I solved the acceleration problem you brought up. I don’t know if that is the way you meant

#20

i wouldn’t use if else statements, for many reasons

  1. you can only have the motors at 100% or 0%
    a) you cant make fine adjustments
    b) if you have any controller drift, than it would go at 100% power when you don’t want it to
  2. you are using the if/ else statements wrong
  3. it is longer and more complicated than it needs to be
1 Like