# IMU Inertial Measurement Unit

(Difference between revisions)

## IMU Script

This script simulates an IMU. You can specify the update rate in the editor. It can use a Sender script to send the readings to a remote machine.

## Code

```var updateFreq = 2.0;
var angVel : Vector3;
var angAccel : Vector3;
var linVel : Vector3;
var linAccel : Vector3;
private var lastPos : Vector3;
private var lastAng : Vector3;
private var lastLinVel : Vector3;
private var lastAngVel : Vector3;
private var timer = 0.0;
private var sender : Sender;

function Start(){
Init();
}

function Update () {
timer += Time.deltaTime;
if(timer>(1/updateFreq)){

lastLinVel = linVel;
lastAngVel = angVel;

var lastPosInv = transform.InverseTransformPoint(lastPos);

linVel.x = (0-lastPosInv.x)/timer;
linVel.y = (0-lastPosInv.y)/timer;
linVel.z = (0-lastPosInv.z)/timer;

var deltaX = Mathf.Abs((transform.rotation.eulerAngles).x)-lastAng.x;
if(Mathf.Abs(deltaX)<180 && deltaX>-180) angVel.x = deltaX/timer;
else{
if(deltaX>180) angVel.x = (360-deltaX)/timer;
else angVel.x = (360+deltaX)/timer;
}

var deltaY = Mathf.Abs((transform.rotation.eulerAngles).y)-lastAng.y;
if(Mathf.Abs(deltaY)<180 && deltaY>-180) angVel.y = deltaY/timer;
else{
if(deltaY>180) angVel.y = (360-deltaY)/timer;
else angVel.y = (360-deltaY)/timer;
}

var deltaZ = Mathf.Abs((transform.rotation.eulerAngles).z)-lastAng.z;
if(Mathf.Abs(deltaZ)<180 && deltaZ>-180) angVel.z = deltaZ/timer;
else{
if(deltaZ>180) angVel.z = (360-deltaZ)/timer;
else angVel.z = (360+deltaZ)/timer;
}

linAccel.x = (linVel.x-lastLinVel.x)/timer;
linAccel.y = (linVel.y-lastLinVel.y)/timer;
linAccel.z = (linVel.z-lastLinVel.z)/timer;
angAccel.x = ((angVel.x-lastAngVel.x)/timer)/9.81;
angAccel.y = ((angVel.y-lastAngVel.y)/timer)/9.81;
angAccel.z = ((angVel.z-lastAngVel.z)/timer)/9.81;

lastPos = transform.position;

lastAng.x = Mathf.Abs((transform.rotation.eulerAngles).x);
lastAng.y = Mathf.Abs((transform.rotation.eulerAngles).y);
lastAng.z = Mathf.Abs((transform.rotation.eulerAngles).z);

timer=0;

sender.Send(linVel + "," + linAccel + "," + angVel + "," + angAccel);
}

}

function OnEnable(){
Init();
}

function Init(){
sender = gameObject.GetComponent("Sender");
}```