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Scratch projects can be connected to the physical world using several different kinds of devices. Some are:
- Makey Makey
- LEGO WeDo Kit
- PicoBoard (also known as ScratchBoard)
- Kinect2Scratch, using Microsoft Kinect
- GoPiGo for Raspberry Pi
- GrovePi for Raspberry Pi
Makey Makey allows people to turn everyday objects into keys and use them with their computer.
- Makey Makey works by opening and closing circuits, using the user's body and other objects as conductors. It uses very little electricity, so it is safe, and it won't be felt
- If two alligator clips are attached to the Makey Makey board, an apple and the user's body, when they touch the apple you, the circuit is completed (closed) and the computer recognizes this as a key is pressed. The Makey Makey uses standard "USB input device" drivers, so the computer thinks Makey Makey is a regular keyboard or mouse even though a unique key has been made.
The default keys are the arrow keys, the space bar, and left click. They can be remapped using the website. Example use of Makey Makey:
- To make Makey Makey work with Scratch, plug in the USB to a computer and create a Scratch program normally. For example, when the right arrow key is pressed, the sprite moves 10 steps.
- Then, connect one of the alligator clips to Earth at the bottom of the Makey Makey board and touch the metal at the other end of the alligator clip with a finger.
- Next, connect another alligator clip to the apple and the right arrow on the Makey Makey board.
- When the metal clip and the apple are touched at the same time, the circuit is completed and the Makey Makey sends a signal to the computer saying a key is pressed. Every time the apple is touched, the sprite will now move 10 steps.
An alternative to using the steps above is by using the Makey Makey Extension.
To purchase a Makey Makey, visit Makey Makey's website.
For information on how to set-up a Makey Makey, visit Makey Makey Set-Up.
For information on different materials to use with Makey Makey, visit Makey Makey Materials.
For information on troubleshooting Makey Makey, visit Makey Makey Troubleshooting.
Article on ideas of uses for Makey Makey, Makey Makey Article.
- Main article: LEGO WeDo Construction Set
The LEGO WeDo kit can be used to make motors and sensors interact with Scratch projects. It has a distance sensor, a tilt sensor, and a motor.
Example uses of the WeDo parts:
- Making a machine move when the distance sensor detects a certain distance.
- Wave a hand to change the size of a sprite when the distance sensor detects a certain distance.
- Using the 'motor to spin attached objects.
- Using the distance sensor to control the speed of the motor.
To find out more about LEGO WeDo parts and how you can use them in Scratch, LEGO Education WeDo Robotics Kit.
To purchase LEGO WeDo, visit the LEGO Education Website.
- Main article: PicoBoard
|This article or section documents something not included in the current version of Scratch (3.0). It is only useful from a historical perspective.|
The PicoBoard provides a way for you to make Scratch projects sense and respond to events/objects in the world outside of the computer.
Examples of use with the PicoBoard:
- Use the sound sensor to make your sprite change how it looks whenever there is a loud sound.
- Use the light sensor to program a sprite to hop up or down whenever a shadow passes by.
- Use the slider and button to control a character in a video game.
- Use the USB cable and four sets of alligator clips that come with the PicoBoard to measure an electrical resistance in a circuit. The alligator clips can be used to build all kinds of custom sensors.
For more ideas on what to make visit the PicoBoard website.
To get started using the PicoBoard visit the PicoBoard Getting Started Guide.
To purchase a PicoBoard visit the SparkFun website.
If you own a ScratchBoard, a product similar to a PicoBoard that was sold through the Scratch website, the support information you'll find at the PicoBoard's website is applicable to your product as well.
If you own a ScratchBoard or PicoBoard and want to know about sensors that you can connect to it, look at the Sensor Types and Sources below.
Sensor Types and Sources
The following list shows different types of sensors that have been used in Scratch Sensor Board projects. (They are typically attached to alligator clip-heads plugged into sensor board jacks A, B, C, or D.) Visit the vendor site for pricing and ordering information.
Name; Description; Vendor Part Number
- Switch; Switch lever spdt 3A PCB; http://digikey.com SW773-ND.
- Temperature; Thermisor NTC 10K OHM 5%; http://digikey.com 317-1258-ND.
- Light; Photocell 5K-20K OHM 4.20 MM; http://digikey.com PDV-P9203-ND.
- Magnetic switch - 1; Switch Reed 10-15AT SPST .5A; http://digikey.com 420-1047-ND.
- Magnetic switch - 2; Switch Reed SPST .5A 12-23 A/T; http://digikey.com HE502-ND.
- Humidity; Consists of a metal electrode on a humidity sensitive membrane mounted on a ceramic substrate; http://rhopointcomponents.com SYH-1NC.
|Note:||When using resistive sensors with the XO microphone port, it appears that the interesting resistance range goes from around 2k to 5k. (Experimentally determined; the user's mileage may vary.)|
Kinect2Scratch works by using the sensor recognition in Scratch and the Microsoft Kinect. The Microsoft Kinect works by recognizing certain bone movements in the human body, such as waving an arm, and Kinect2Scratch has created the software to have Scratch recognize this as well.
To download the Kinect2Scratch software, visit Kinect2Scratch's Website.
For the set-up guide on how to install and use Kinect2Scratch, visit Kinect2Scratch's Set-Up Guide.
For ideas on what to do with Kinect2Scratch and sample projects, visit Kinect2Scratch's Examples.
GoPiGo for Raspberry Pi
GoPiGo is a robot that is controlled by an onboard Raspberry Pi to create an autonomous vehicle. The Raspberry Pi is a low-cost Linux-based computer that is very popular in classrooms. Once assembled, the GoPiGo can be controlled with Scratch 1.4, found on board the 'Raspberry Pi.
The easiest way to control GoPiGo is through Wi-Fi and a portable computer running VNC viewer. That way, GoPiGo can be untethered. It's also possible to hook it up through an Ethernet cable, or even as a desktop setup with keyboard and monitor.
Details on how to set it up can be found at Getting Started with GoPiGo
- Make the GoPiGo go forward, backward, turn, and of course, stop.
- Blink your left turn signal, and then proceed with the turn.
- Take a GoPiGo outside and race others. (Wi-Fi must be accessible)
To purchase a GoPiGo, visit GoPiGo Starter Kit Page
To see various projects that can be done with a GoPiGo, visit GoPiGo Projects.
GrovePi for Raspberry Pi
The Dexter Industries GrovePi is an Internet of Things (IoT) device built on the Raspberry Pi. The GrovePi can be programmed using the native Scratch installed on the Raspberry Pi (Scratch 1.4 or NuScratch). Programs that read plug-and-play sensors, and control everyday devices can be written.
The GrovePi can be used with the Raspberry Pi Models A, A+, B, B+, 2 and 3.
- LEGO Education WeDo Robotics Kit
- Dexter Industries GoPiGo For Raspberry Pi
- Connecting to the Physical World (forum)