pxt-ev3/docs/reference/motors/motor/ramp.md

Ramp

Schedules an acceleration, constant and deceleration phase at a given speed.

motors.largeA.ramp(50, 100, 500, 100)

The speed setting is a percentage of the motor's full speed. Full speed is the speed that the motor runs when the brick supplies maximum output voltage to the port.

Parameters

• speed: a number that is the percentage of full speed. A negative value runs the motor in the reverse direction.
• acceleration: the number of movement units to rotate for while accelerating.
• value: the number of movement units to rotate for.
• deceleration: the number of movement units to rotate for while decelerating.
• unit: the movement unit of rotation. This can be milliseconds, seconds, degrees, or rotations. If the number for value is 0, this parameter isn't used.

Example

This is an interactive program that lets you change the values of the acceleration and deceleration and see the effects.

let steady = 0
let dec = 0
let acc = 0
brick.buttonLeft.onEvent(ButtonEvent.Pressed, function () {
    acc += -100
})
brick.buttonEnter.onEvent(ButtonEvent.Pressed, function () {
    motors.largeB.ramp(50, steady, MoveUnit.MilliSeconds, acc, dec)
})
brick.buttonRight.onEvent(ButtonEvent.Pressed, function () {
    acc += 100
})
brick.buttonUp.onEvent(ButtonEvent.Pressed, function () {
    dec += 100
})
brick.buttonDown.onEvent(ButtonEvent.Pressed, function () {
    dec += -100
})
acc = 500
steady = 1000
acc = 500
forever(function () {
    brick.showValue("acc", acc, 1)
    brick.showValue("steady", steady, 2)
    brick.showValue("dec", dec, 3)
    brick.showString("acc: left/right", 5)
    brick.showString("dec: up/down", 6)
    brick.showString("run large B: enter", 7)
})

See also

tank, steer, stop