Create a unique structure that spins in the wind—then experiment with its rotation using the Science Journal app
At least 20 minutes to prepare sensor, base, and testing area
In Wind Spinners: Getting Ready, you’ll set up your sensor and testing station and then you’ll move on to Wind Spinners: Designing and Building, where additional tools and materials will be needed.
Tools and Materials
- Battery and battery connector
- External sensor (light sensor board)
- Microcontroller base
- USB micro cable
- Cardboard encoder
- Hockey puck
- Metal rod
- Sensor housing
- Electrical and masking tape
- Hand drill
- Jumper wires
- Screwdriver set and screws
Prepare the microcontroller and external sensor.
Set up the components needed to record data from your wind spinner.
1. Load the Science Journal program on your microcontroller
Microcontrollers are small programmable computers. By loading different programs onto the microcontroller you can use and play with it in different ways. You’ll use the microcontroller to help interpret the information from the light sensor board in the form of graphs and illustrations in Science Journal.Download the Science Journal program and follow the instructions to install the firmware on your microcontroller. (If you have a Science Journal kit, the program is preloaded so you can skip to the next step.)
2. Set up the microcontroller base.
Now that your microcontroller is programmed, use the two screws provided to attach it to the base. This will make it easier to move it around as you test your wind spinner.
3. Prepare the light sensor board.
Snap the connecting wires, provided in the light sensor board packet, into the board.
If you’d like to extend the distance between your board and the microcontroller, attach a jumper wire to each of these wires. This can be helpful when you begin experimenting with your wind spinner. The colors that you choose do not matter; they are just extending the wires. You can use electrical tape to secure the connections.
4. Connect the light sensor board to the microcontroller.
Insert the end of each wire into the corresponding microcontroller port as diagrammed below:
OUT to A0 pin
VCC to 5V pin
GND to GND pin
5. Turn on the microcontroller.
Connect the phone charger to the micro USB port and plug it in. Or, for more flexibility, get power using the 9V battery and connector. You’ll know the microcontroller is on when you see the green light turn on. Turn off the microcontroller when not in use.
6. Connect the sensor to the Science Journal app.
Now you’re ready to test your setup with Science Journal. Get out your phone and open the Science Journal app.
To pair your microcontroller and light sensor board using Science Journal, press the Add Sensor icon in the top right.
Bluetooth allows you to connect to an external sensor.
The microcontroller has a unique identifying ID, SCIXXXX, that will show up under available devices; click on this ID to pair with the device.
The microcontroller can only be paired with one phone at a time. If using multiple microcontrollers, it can be helpful to write the unique identifying ID, SCI XXXX, on a piece of masking tape or sticker and apply it to both the microcontroller base and the phone. This will help easily identify the microcontroller when pairing with the phone.
7. Reading data from an external sensor.
When you pair your sensor it should automatically connect as a Raw sensor. This setting allows you to see the raw data value from any external sensor that you may have connected. You’ll use this setting to experiment with the photoresistor on the light sensor board, which is helpful for understanding how it works. Later, you’ll use the Rotation setting with the light sensor board to measure the wind spinner’s speed.
Return to Observe mode and select the Raw icon from the Sensor menu.
To test your light sensor board, cover and uncover the photoresistor, , on your light sensor board. What do you notice in graph mode when the photoresistor is covered and uncovered?
The photoresistor is used to measure the amount of light received. When the photoresistor is covered, the reading on your graph will decrease. When it’s uncovered, it will increase.
8. Setting up the ambient light sensor for rotation.
To measure rotation speed, you’ll need to attach the light sensor board to the purple sensor housing. First, insert the photoresistor, into the large hole on the bottom of the purple sensor housing. Then use tape to secure the board to the base, being careful not to tape over the smaller hole in the center of the housing.
9. Make a stand for your wind spinner.
Next you’ll drill a hole into the hockey puck. Tape your hockey puck down to a table to hold it in place. Using the hand drill and a 3⁄32 drill bit, drill a ¼- to ½-inch-deep hole into the middle of your puck.
Drill straight down, not at an angle, in small increments to ensure that the drill bit does not get stuck in the rubber.
To put the stand together, place the rod through the small hole in the middle of the sensor housing and then insert the rod into the hole in the puck.
10. Assemble the axle and cardboard encoder.
Take one cardboard encoder and tape it to the bottom of a straw, leaving a bit of the straw poking out the bottom.
Make sure there is not more than a ¼ inch of the straw sticking out of the cardboard encoder. If there is more, the excess light will cause inaccurate readings in Science Journal.
The straw will be the foundation for building your wind spinner.
When your wind spinner rotates, the cardboard encoder window will also rotate, changing the amount of light reaching the sensor. Science Journal can measure the rotation rate based on this changing light information; essentially it is “seeing” how frequently the window passes over the sensor.
11. Test the rotation (RPM) setting.
Experiment using the cardboard encoder to measure rotations per minute, or RPM.
Change the external sensor type.
When you’re finished experimenting with the photoresistor in Raw mode, change the sensor settings to Rotation (RPM). This sensor will help you measure the wind spinner’s speed. To change the sensor settings to Rotation (RPM), press the Add Sensor icon in the top right, choose the Gear icon next to your paired device, then under Device Settings change Raw to Rotation (RPM) .
Place the straw on your wind spinner stand.
Line up the window of the cardboard encoder with the opening of the light sensor board. Use Science Journal to watch as the sensor reads pulses of light and dark as the window rotates over the sensor.
Rotate the straw by hand:
What do you notice on your graph?
What happens when you spin it slowly? When you spin it faster?
While spinning the cardboard encoder at a moderate pace, count the number of rotations in one minute while you also record your data in Science Journal. How does the number of spikes on the graph relate to how many times you’ve rotated the encoder?
You’ll need ample light to shine through the window on the cardboard encoder for this to work. If you’re not seeing clear results in Science Journal, then move to a better-lit space or use the flashlight.
12. Set up a testing area.
For this activity, you’ll be using a fan as your wind source. Set up a testing station before building your wind spinners.
Place a table and fan(s) in an area where they will not interfere with your work space. If using multiple fans, experiment with using them separately or together to create stronger wind.
Wind Spinners: Designing and Building
Create a unique structure that spins in the wind—then experiment with its rotation using the Science Journal app.
1. Take a moment to think about wind.
Where have you noticed the wind interacting with people, places, and things? What was the effect of wind in these scenarios? Use these observations to inform your wind spinner design.
3. Build your design.
Use the masking tape and hot glue to attach materials to the straw.
Leave at least 3 inches of straw between the top of the cardboard encoder and the start of your design. If your wind spinner is too close to the cardboard encoder there’s a good chance it will be blocking too much light, preventing the light sensor board from receiving information about the spinner’s rotation.
4. Set up a project and an experiment in Science Journal.
When you’re ready to test your wind spinner with the fan, open a new project in Science Journal so you can document your observations.Add new experiments to document any observations or ideas you would like to test. See Science Journal: Getting Started for information on projects and experiments.
5. Test your wind spinner.
Place your wind spinner in front of a fan. What do you notice? What do you see happening in Science Journal?
Try holding the rod at different angles to the fan. Play with how close to or far away from the fan you place the wind spinner. Now think about experimenting with your design. Did your wind spinner do exactly what you expected? What was surprising to you? What do you think you could adjust to make your wind spinner work the way you hoped?
6. Brainstorm: What variables can you change?
You may have a specific goal in mind for your wind spinner, or you may not. Either way, a good way to start exploring is to make a list of everything you think you can change. For example: What happens if you...
change the length of the straw shaft?
change the shape, size, angle, or direction of the sails or blades?
add or subtract blades or sails?
change the angle of your rod?
use different materials?
What other questions can you ask that begin with “What happens if…”?
In Science Journal, each time you make a change and create a new experiment, you can add photos and notes on your wind spinner. Try making multiple trials for each experiment. When you review your experiments later, you can compare how the designs and outcomes are connected.
It’s important to change only one variable at a time per experiment so that you can connect those changes to the results you see in the app.
Can you find a way to make your wind spinner turn faster or slower, or spin in the opposite direction? What other challenges can you think of? Using Science Journal, document all your challenge questions and conclusions.
Create a new wind spinner, different from the first. Test, document, and investigate new materials, designs, and questions.
What’s Going On?
Your wind spinner may (or may not) be a beautiful artwork, but if it spins, it’s also a turbine—a machine for extracting energy from a passing flow of water, steam, or in this case, air.
Turbines take energy from fluids—liquids, gases, and plasmas—by harnessing Newton’s Third Law of Motion: For every action, there is an equal and opposite reaction. If a fan blade pushes passing wind to the right, the wind will simultaneously push the blade to the left.
Some designs spin furiously, while others don’t spin at all. An object rotates when it’s acted on by a twisting force, called a torque. But rotation only occurs for a net torque, that is, a torque that isn’t being canceled out by another torque in the opposite direction. If a design wiggles but doesn’t spin, it may be that parts of the wind spinner are working at cross purposes, creating equal but opposite torques that cancel each other out.
Friction may also slow or halt rotation in your wind spinner. Any two objects in contact experience frictional forces that act to oppose motion between them. Friction can be reduced but never completely eliminated.
As your wind spinner turns, it rotates the sensor base, creating periods of light and dark on the sensor that register in the Science Journal as revolutions per minute (RPM). RPM is a measure of the frequency of rotation around a fixed axis in one minute.
Take the fun outside, and build a wind spinner that can handle the great outdoors. Testing in the natural environment can be very different from testing with a fan. How might this influence your design? Materials, too, may need to be adjusted; what you used for the indoor setting may be too fragile for outdoor use.
You’ll be using a light sensor for this activity that needs a fair amount of light to work properly, so set up the testing area in a well-lit space. A flashlight can be used to increase the amount of light in a dim space or provide a constant light source.
Build at least one example of a wind spinner in advance. This will help you find out what might inspire people and what challenges they might face.
Organize the materials so your group can easily get started with assembling the different pieces and clearly see what’s available to design and build with.
When finished making and testing the wind spinners, dismantle them but keep the sensor setup, the stand, and any making materials that can be reused. Make sure everyone has had a chance to document their wind spinner designs before they’re dismantled.
Troubleshooting the Electronics.
When in doubt, press the Reset button on the Arduino.
If you’re having trouble getting a reading or response in Science Journal, double check that you’ve plugged everything in correctly: Is each wire on the light sensor board plugged into its corresponding pair on the microcontroller? Is your phone paired to the correct board?
If you accidentally touch something metal to either your microcontroller or the metal pins on the light sensor board, you might lose the data connection. Restart the microcontroller and have the app “forget” the sensor and then re-add it.