pxt-ev3/docs/tutorials/touch-sensor-values.md
2018-06-12 06:46:44 -07:00

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# Using Touch Sensor Values
## Introduction @unplugged
Use the Touch Sensor value to stop a running motor.
![Touch sensor and motor attached to brick](/static/tutorials/touch-sensor-values/touch-to-stop.gif)
## Step 1
Open the ``||brick:Brick||`` Toolbox drawer. Drag an ``||brick:on button||`` block onto the Workspace, and place it anywhere.
```blocks
brick.buttonEnter.onEvent(ButtonEvent.Pressed, function () {
})
```
## Step 2
Open the ``||motors:Motors||`` Toolbox drawer. Drag out a ``||motors:run||`` block onto the Workspace, and drop it into the ``||brick:on button||`` block.
```blocks
brick.buttonEnter.onEvent(ButtonEvent.Pressed, function () {
motors.largeA.run(50)
})
```
## Step 3
Open the ``||logic:Logic||`` Toolbox drawer. Drag out an ``||logic:if then||`` block onto the Workspace, and drop it into the ``||loops:forever||`` block.
```blocks
forever(function () {
if (true) {
}
})
```
## Step 4
Open the ``||sensors:Sensors||`` Toolbox drawer. Drag out a ``||sensors:touch is pressed||`` block onto the Workspace, and drop it in the ``||logic:if then||`` block replacing ``true``.
```blocks
forever(function () {
if (sensors.touch1.isPressed()) {
}
})
```
## Step 5
Open the ``||music:Music||`` Toolbox drawer. Drag out a ``||music:play sound effect||`` block onto the Workspace, and drop it under the ``||logic:if then||`` block.
```blocks
forever(function () {
if (sensors.touch1.isPressed()) {
music.playSoundEffect(sounds.animalsCatPurr)
}
})
```
## Step 6
In the ``||music:play sound effect||`` block, use the drop-down menu to select the ``information touch`` sound effect.
```blocks
forever(function () {
if (sensors.touch1.isPressed()) {
music.playSoundEffect(sounds.informationTouch)
}
})
```
## Step 7
Open the ``||motors:Motors||`` Toolbox drawer. Drag out a ``||motors:stop||`` block onto the Workspace, and drop it in after the ``||music:play sound effect||`` block.
```blocks
forever(function () {
if (sensors.touch1.isPressed()) {
music.playSoundEffect(sounds.informationTouch)
motors.largeA.stop()
}
})
```
## Step 8
Now, plug your EV3 Brick into the computer with the USB cable, and click the **Download** button at the bottom of your screen. Follow the directions to save your program to the brick.
Attach a Large motor to Port A, and a Touch sensor to Port 1 on your brick. Test your program by pressing the ENTER button. When the motor starts, press the touch sensor. Does the motor stop as expected?