Codea deviceShaking() function

main.lua

-- Accelometer Shake
 
supportedOrientations(LANDSCAPE_RIGHT)
 
function setup()
    print("Shake a few times until the rect() exceeds the ellipse().")
end
 
local function deviceShaking()
    local acceleration = UserAcceleration
    local intensity    = 4 -- adjust min. shaking intensity to trigger this event!
    if UserAcceleration.x > intensity or acceleration.y > intensity or acceleration.z > intensity then
        _deviceShakeUpdatedAt = ElapsedTime
        _deviceShakeBegunAt   = _deviceShakeBegunAt or ElapsedTime
 
        -- first shake triggers listening process
        -- listen if shaking continues for [x] seconds then device is considered shaking on purpose
        if (ElapsedTime - _deviceShakeBegunAt) >= .5 then return true end
    end
    if _deviceShakeUpdatedAt and (ElapsedTime > (_deviceShakeUpdatedAt + .5)) then
        _deviceShakeBegunAt   = nil
        _deviceShakeUpdatedAt = nil
    end
    return false
end
 
function draw()
    if deviceShaking() then
        print("DEVICE SHAKING")
        background(255, 60, 25)
    else
        background(100)
    end
 
    translate(WIDTH/2, HEIGHT/2)
    noFill()
    stroke(0)
    strokeWidth(2)
    rectMode(CENTER)
    ellipse(0, 0, 100)
    rect(UserAcceleration.x * 40, UserAcceleration.y * 40, 10)
end