How to bring tech and making into any classroom! (1/4)

Turns out Ms. Frizzle from The Magic School Bus had it right all along! In the era of the Next Generation Science Standards, there is a great deal of evidence that experiential and project-based learning are effective approaches to education. As described in the Cambridge Handbook of Learning Sciences, project-based classrooms provide opportunities for students to “investigate questions, propose hypotheses and explanations, discuss their ideas, challenge the ideas of others, and try out new ideas.” All of this leads to higher test scores than in traditional classrooms.
While we educators may lack the magic necessary to shrink our bodies or travel through the solar system, technology can be an excellent, “magic-like” tool for teaching project-based learning across a wide variety of subjects. When implemented with care and intention, electronics and tech can enhance and expand the realm of possibilities, providing students with direct, hands-on experience of phenomena. A handful of carefully chosen equipment and materials provide an open-ended platform for endless variations of creativity, application, and exploration.
One of the major obstacles in getting started is figuring out what, and how much, to choose. The plethora of options can be daunting and it is not always obvious how to incorporate into a classroom. Here are four principles to help guide you as you make lesson and product choices:
1. Use what you have;
2. Let the students lead (peer-to-peer and even peer-to-teacher education);
3. Broken is better; and
4. Pass it on!
The remainder of this article will expand on the first principle: Use what you have. We will publish more in-depth articles on the remaining principles in the weeks to come, so stay tuned!
Principle 1: Use what you have.
Whether you are looking to teach history or robotics, there are many learning opportunities within everyday materials, particularly when paired with “smart” devices like computers, microcontrollers, or other Integrated Circuits (“ICs”).
Investing in an appropriate microcontroller* for your classroom gives your students more diverse options for projects and invites cross-disciplinary learning opportunities, a key foundation of NGSS. Microcontrollers can add coding to art, and art to coding. If you need some help choosing an effective microcontroller for your classroom, here’s an overview of some common, beginner-friendly microcontrollers.
Free or inexpensive components can be used in alternative ways: LEDs are also light sensors, motors generate electricity when spun, and speakers can be used as a microphone! Finding alternative uses for parts offers students a fun challenge and is a great way to explore connections across fundamental phenomena: Why is a motor also a generator? What does this tell us about how electricity and magnetism work together?
Encourage your students to ask deeper questions and look for connections.
Is there a closet full of old computers, telephones, printers, etc? Perfect! Old tech is often easier to understand because the pieces inside are larger and easier to see than in newer technology. Larger parts are also easier to harvest, or pull out for closer examination and/or use in other projects.
Guide the students in taking apart unused devices. If it’s broken, can the students figure out why? Is it possible to fix or hack it to do something different? If not, how could the students use the parts in new ways? What parts might the students harvest for other projects?
Here is a list of some parts that can be harvested without specialized tools and used in a wide variety of projects:
  • Motors
    • Motors can be used in a wide variety of projects including robotics, puppet shows, art projects, and creative music-making. This is a wonderful alternative to traditional robotics programs as it allows for a wider variety of ingenuity and a deep understanding of how motors function.
    • There are different types of motors that require different signals to turn on: DC motors, stepper motors, and servo motors are the most common. DC motors can be powered directly with a battery, while stepper motors will require a more finely tuned signal from a computer or microcontroller. Unsure what type of motor you discovered? Use three or four AA batteries or a 9V battery to touch the motor connections and explore how and when it moves.
  • Speakers
    • From special effects to science experiments, sound is exciting! Harvested speakers offer the opportunity to observe how sound waves are generated, how sound travel through different materials, and how waves move in general.
    • Connect a 9V battery to the speaker terminals to move and “beep” it, or use the speaker with a microcontroller and/or other amplifier circuit to create instruments, sound effects, and music. Speakers can also be used as an input when connected to an audio amplification circuit.
  • Electromechanical parts like switches, pushbuttons, relays, and connectors
    • Switches and buttons provide a way for us to interact with circuits and electronics. They can be used to explore analog and digital signals, build logic gates, create cause-and-effect machines, and design communication systems, as well as many other possibilities.
    • A relay is an electronic switch for two separate circuits that make a “click” sound when activated. Relays are one way to control motors with a lower-power circuit.
    • Electrical connectors come in an astounding variety of types, shapes, mechanical and electrical connection mechanisms. They help make the electronics sturdier and easier to store, transport, and modify. And of course, they can be used to add flair to projects sans electricity!
  • Sensors
    • Many electronics have infrared (IR) transmitters and/or receivers, which can be hacked to build remote controls for robots and other projects. Solar path lights and CD/DVD drives contain light sensors, security lights have passive IR sensors, and many printers have optical encoders!
  • Transistors
    • If you have tech that qualifies as antique, you may be able to find transistors that can be reused (in newer tech, they are so small that they are invisible to the human eye). Observing transistors in older tech is an excellent pathway through computer history, design, and hardware function.
    • If observation of transistors isn’t the educational opportunity you need, they can be used to add autonomy and logic to circuits, or can act as a controller for output devices like lights, speakers, or low-power motors.
  • Mechanical parts like springs, gears, drive shafts, etc.
    • One of the main challenges in doing engineering projects is having make functional gears. Avoid all of that by taking apart a printer and pulling out the mechanical components. Electronic toys that move are another good source for gears and mechanical mechanisms, and can be hacked or “mashed” together in combinations that span delightful and eerie.
A quick note on safety when doing take-aparts:
  • Unplug the electronics and leave unplugged for a minimum of two (2) weeks.
  • Avoid large appliances, microwaves, and ink-jet printers (or just take out the ink cartridges)
  • Always wash hands afterwards. Students should keep food and drink in closed containers and off the tables.
  • Do not force anything open or closed. The biggest hazard with take-apart activities are sharps caused by broken parts when someone tries to pull a case open without properly removing all the screws.
Even without harvesting parts, seeing the inside of electronics is an effective and memorable way to explore how these devices are made and how they function. Once students see the insides of a few different devices, they will quickly identify connections across all electronics and have a better understanding of the “magic” behind the tech.
Aside from electronics, there are tons of useful and versatile materials all around us! Cardboard, paper, plastic containers, pipe cleaners, brads, clothespins, and office supplies are incredibly versatile. Use these materials in conjunction with the tech you have available, or as stand-alone project-based lessons in science, math, history, and other subjects. How might your students explore various ways to build moving mechanisms with cardboard and paper brads? How might your students use colored paper to explore how light is absorbed and reflected? How might your students explore and visualize sound?
Often, the key to incorporating project-based learning is providing the appropriate challenge. The best challenges allow for a wide variety of creations, are accessible and relevant to the students’ lives, and are as fun to mess up as they are to achieve! Challenges do not need to be binary or only one goal or path-oriented. The most effective challenges are those with the most room for surprises and “broken” rules.
With all of that said (well, written), the only thing you really need to remember is that you can do a lot, including incorporating and meeting NGSS, with what you already have. Look around, look inside, and look for connections!
Please reach out if you have any questions about this principle or if you’re looking for ideas in getting started. Happy learning!
* Wait wait wait… what is a microcontroller? Excellent question! A microcontroller is a “simple computer” that runs one program at a time. Examples of microcontrollers are Internet routers, TV remotes, and video game controllers.

Scientists discover a way to send low energy and long range wireless signals!

Whenever your phone rings or you get a text message, radio waves carry that information, whether in the form of a voice or letters, across vast distances. Different forms of wireless communication use different types of radio waves, which are differentiated by their wavelength and frequency. Cellphone radio waves can travel far, but eventually they lose energy. To make sure that you get that very important text message, cellphone service providers amplify the signal with radio towers. But, some radio waves can travel even farther, like “very low frequency”, or VLF radio signals can travel miles, through air, land, and even water! This method of sending wireless signals is a great way for aircraft and submarines to navigate and communicate.

The catch with these low frequency signals is that creating an energy-efficient signal requires an extremely large antenna, often more than a kilometer long! This requirement limits the uses and practicality of these low frequency signals.

That is all about to change (insert obligatory dun dun dunnnnnn!!!):

Mark Kemp of of the Standard Linear Accelerator (SLAC) and his collaborators have been trying to build a low-energy and long-range radio antenna. In other words, they are trying to have it all.

Kemp and collaborators successfully built a long-range antenna prototype (pictured right) by using a creative approach: rather than using metal as is traditional for antennas, this collaboration used a material that expands and contracts to generate a radio wave. This allows a much smaller antenna that is able to be portable and long range!

We are excited for the possibilities of improved low-energy and long-range communication, particularly in remote areas, as it improves connectivity, safety, and access to services.

To learn more, you can read a more detailed summary of the prototype here: https://physicstoday.scitation.org/do/10.1063/PT.6.1.20190530a/full/

Or read the original published paper in the journal Nature: https://www.nature.com/articles/s41467-019-09680-2

Science Research is Important! Here’s why.

Pierre Teilhard de Chardin, a paleontologist, geologist, philosopher, and Jesuit priest, wrote: “The history of the living world is an elaboration of ever more perfect eyes in a cosmos in which there is always something new to be seen.” Humans have long sought answers to the mysteries of the natural world. Eventually, our curiosity helped us to develop the scientific method.

 

Today, support for basic scientific research in the United States is shrinking. There are fewer opportunities for careers in research, and we are attracting less and less qualified students both domestically and abroad. This is alarming as the neglect of basic research could be disastrous for our society and our species.

 

As stated by Daniel Kleppner, a physicist at MIT, “If our civilization succeeds in learning to live in harmony with the natural world, science will have played a crucial role in the transition.” Right now, we must convince Congress of this urgent fact. There is much to be optimistic about: the numbers of scientifically literate citizens and members of Congress are growing. But we must speak up about the importance of basic research if we are to save it.

Image result for climate change

Climate change is a serious and life-threatening hurdle for our species. We need new ways to deal with the rapid change in our climate and in our ecosystems. In fact, the latest report from the Intergovernmental Panel on Climate Change (“IPCC”) concludes “that previous reports erred in being to cautious: The time to stem the flow of greenhouse gases is shorter than had been estimated. We face the possibility of a runaway situation in which an increase in global temperature feeds back to accelerate global heating. Such a process would lead to a massive change in climate and a catastrophic elevation of sea level. We face a threat to civilization.”

Basic research has brought us tools and techniques that allow us to measure data critical to understanding Earth and the cosmos. For example, GPS few out of simple curiosity about general relativity, studies of atomic nuclei brought us the invention of MRI, and experiments of molecules in space lead to the development of the laser.

Yayy science for bringing us lasers!!
Humanity needs basic research to explore the mysteries of our existence as well as to ensure our species continues to thrive in harmony with nature. We need scientists from all backgrounds to bring new ideas and novel solutions to the table. We need you, dear reader, to ask your most burning questions and to seek answers using whatever tools and resources are available. And of course, to promote science in the classroom, in the community, and in Congress.

 

Please consider calling your local, state, and federal representatives and urge them to support funding for basic scientific research. Our very lives depend on it.

 

 

The inspiration for this post:
https://doi.org/10.1063/PT.3.4194

Using Arduino for Citizen Science!

Science allows us to ask our most pressing questions and explore all sorts of curiosities. With some thought, hard work, and patience, we can use our explorations to build a better understanding and appreciation of the complex and beautiful world around us.

This tutorial will teach you how to use an Arduino (uno) microcontroller, how to use different types of sensors, and how to gather and visualize data. Along the way, we’ll build three projects: a tilt switch, a temperature and humidity sensor, and a light sensor!

Difficulty Level: Beginner

Read Time: 20 min

Build Time: Depends on your project! (Projects in this tutorial take about 15 – 20 min)

Pssst, What’s the Difference Between Citizen Science and “official Science”?

The biggest difference is that citizen science is, as I love to say, “hand wavy”, which means that there are lots of errors and uncertainties and no rigorous process to identify them. Because of this, conclusions reached through citizen science are much less accurate than science-science and should not be relied upon to make serious/life-altering/life-threatening claims or decisions.*

That being said, citizen science is a great way to build a fundamental understanding of all sorts of fascinating scientific phenomenon and is good enough for most day-to-day applications.

*If you are doing citizen science and you discover something potentially dangerous (e.g. high lead levels in water), inform your educator (if applicable) and contact the relevant authorities and professionals for assistance.

What Is Arduino??

Arduino is a microcontroller board and Integrated Development Environment (“IDE”), which is a fancy way of saying “coding program”. For beginners, I highly recommend Arduino Uno boards because they are super robust, reliable, and powerful.

Arduino boards are a good choice for citizen science projects because they have lots of input pins to read in both Analog and Digital sensors (we’ll get more into this later).

Of course, you can use other microcontrollers for citizen science depending on your (or your students’) needs, abilities, and comfort level. Here is an overview of microcontrollers to help ya decide what is best for you!

To flash, or program, an Arduino board, plug it in via USB, then:

1. Select the type of Arduino you’re using under Tools -> Boards.

 

2. Select the port (aka where it’s connected to your computer).

 

3. Click the Upload button and check that it finishes uploading.

Tools & Materials

If you’re just getting started, getting a kit is a quick & easy way to get a bunch of parts at once. The kit I’m using in this tutorial is the Elegoo Arduino Starter Kit.*

Tools

  • Arduino Uno
  • USB A to B cable (aka printer cable)
  • Jumper Wires
    • 3 male-to-male
    • 3 male-to-female
  • Breadboard
    • Optional but recommended to make your life easier and more fun 🙂

Materials

For the projects covered in this tutorial, you’ll need these parts from the Elegoo Arduino Starter Kit:

  • Tilt Switch
  • DTH11 Temperature and Humidity Sensor
  • LED
  • 100 Ohm Resistor

*Full disclosure: I purchase these same kits for workshops, but the kit used in this tutorial was donated by the lovely folks at Elegoo.

What Kinds of Sensors Can We Use?

When designing a science experiment, we typically start with a question: How much CO2 do plants absorb in a day? What is the impact force of a jump? What is consciousness??

Based on our question, we can then identify what we want to measure and do some research to figure out what sensor we can use to gather data (although it miiight be a bit tricky to gather data for that last question!).

When working with electronics, there are two main types of sensor data signals: Digital and Analog. In the photo, the first two rows of parts are all digital sensors, while the top two rows are analog.

There are many different types of digital sensors, and some are more challenging to work with than others. When doing research for your citizen science project, always check how the sensor puts out data (srsly tho) and make sure you can find an (Arduino) library for that specific sensor.

In the three projects covered in this tutorial we’ll use two types of digital sensors and one analog sensor. Let’s get a-learnin!

Digital Sensors!

Part 1: the Easy Ones

Most sensors you’ll use output a Digital Signal, which is a signal that is either on or off.* We use binary numbers to represent these two states: an On signal is given by a 1, or True, while Off is 0, or False. If we were to draw a picture of what a binary signal looks like, it would be a square wave like the one in the photo below!

There are some digital sensors, like switches, that are super easy and straightforward to measure because either the button is pushed and we get a signal (1), or it is not pushed and we have no signal (0). The sensors pictured in the bottom row of the first photo are all simple on/off types. The sensors on the top row are a bit more complex and are covered after our first project.

The first two projects in this tutorial will teach you how to use both types! Onward to build our first project!!

*On means an electrical signal in the form of electric current and voltage. Off means no electrical signal!

Project 1: Tilt Switch Digital Sensor

For this first project, let’s use a tilt switch, that black cylindrical sensor with two legs!
Step 1: Insert one leg of the tilt switch into Arduino Digital Pin 13, and the other leg into the GND pin right next to pin 13. Orientation doesn’t matter.

Step 2: Write a sketch that reads in and prints out the status of Digital Pin 13.

Or you can just use mine!

If you’re just getting started in coding, read through the comments to better understand how the sketch works and try changing some things to see what happens! It’s OK to break things, that’s a great way to learn! You can always re-download the file and start over 🙂

Step 3: To see your live data, click on the Serial Monitor button.

.. aaaand that’s it! You can now use the tilt switch to measure orientation! Set it up to call out your kitty when it knocks something over, or use it to keep track of how tree branches move during storms! .. & there are probably other applications in between those two extremes.

Digital Sensors!

Part 2: PWM and Serial Communication

There are many ways to create more complex digital signals! One method is called Pulse Width Modulation (“PWM”), which is a fancy way of saying a signal that is on for a certain amount of time and off for a certain amount of time. Servo motors (which can be used to measure position) and ultrasonic sensors are examples of sensors that use PWM signals.

There are also sensors that use serial communication to send data one bit, or binary digit, at a time. These sensors require some familiarity with reading datasheets and can be pretty tricky if you’re just getting started. Fortunately, common serial sensors will have code libraries* and sample programs to pull from so you can still cobble together something functional. More details on serial communication protocols is beyond the scope of this tutorial, but here is a great resource on serial communication from SparkFun to learn more!

For this sample project, let’s use the temperature and humidity sensor (DHT11)! This is a lil’ blue square with holes and 3 pins.

First we’ll need a couple of special libraries for the DHT11 sensor: the DHT11 library and the Adafruit Unified Sensor library.
To install these libraries (and most other Arduino libraries):

Step 1: Open up the Arduino library manager by going to Sketch -> Libraries -> manage Library

Step 2: Install and activate the DHT library by searching for “DHT” and then clicking Install for the “DHT Arduino Library” .

Step 3: Install and activate the Adafruit Unified Sensor library by searching for “Adafruit Unified Sensor” and clicking install.

Step 4: Insert the DHT library into your open sketch by going to Sketch -> Libraries, and clicking on the “DHT Arduino Library.  This will insert a couple of new lines at the top of your sketch, which means our library is now active and ready to use!

*Just like your fav local library, code libraries are a wealth of knowledge and other folks’ hard work that we can use to make our lives easier, yay!

Project 2: Temp and Humidity Digital Serial Sensor

 

Grab 3 male-to-female jumper wires from the Elegoo Arduino Starter Kit and we’re ready to go!

Step 1: With the header pins facing you, connect the rightmost header pin on the DHT11 to an Arduino ground (“GND”) pin.

 

Step 2: Connect the middle header pin to Arduino 5V output pin.

 

Step 3: Connect the leftmost header pin to Arduino Digital Pin 2.

Step 4: Finally, read the DHT library and try your hand at writing a sketch! Oooor you can use mine or the DHT test example sketch within Arduino -> Examples!

When you’ve got it up and running, go forth and measure the temperature and humidity of all the things! .. Like an animal’s breath, a greenhouse, or your favorite climbing spot at different times of the year to find the *perfect* sending temp.

Analog Sensors!

After the difficult dive into digital sensors, analog sensors can seem like a breeze! Analog signals are a continuous signal, like the photo below.

Most of the physical world exists in analog (e.g. temperature, age, pressure, etc.), but since computers are digital*, most sensors will output a digital signal. Some microcontrollers, like Arduino boards, can also read in analog signals**.

For most analog sensors, we give the sensor power, then read in the analog signal using the Analog Input pins. For this test, we’ll use an even simpler setup to measure the voltage across an LED when we shine a light on it.

*Computers use digital signals to store and transmit info. This is because digital signals are easier to detect and are more reliable, since all we’ve got to worry about is getting a signal or not versus having to worry about the quality/accuracy of the signal.

** To read in an analog signal on a digital device, we must use an Analog-to-Digital, or ADC, converter, which approximates the analog signal by comparing the input to a known voltage on the device, then counting how long it takes to reach the input voltage. For more info, this is a helpful site.

Project 3: LED As a Light Sensor!

Grab an LED (any color except white), a 100 Ohm resistor, and 2 jumper cables. Oh, and a breadboard!

Step 1: Insert the LED into the breadboard with the longer leg on the right side.

Step 2: Connect a jumper wire from Arduino Analog Pin A0 and the longer LED leg.

Step 3: Connect the resistor between the shorter LED leg and the breadboard negative power rail (next to the blue line).

Step 4: Connect the Arduino GND pin to the negative power rail on the breadboard.

Step 5: Write a sketch that reads in Analog Pin A0 and prints to the Serial Monitor!

Here is a sample code to get ya started.

Visualizing Data: Arduino IDE!

The Arduino IDE comes with built-in tools to visualize data. We’ve already explored the basics of the Serial Monitor which allows us to print sensor values. If you want to save and analyze your data, copy the output directly from the Serial Monitor and paste into a text editor, spreadsheet, or other data analysis tool.

The second tool we can use to see our data in the Arduino program is the Serial Plotter, a visual version (aka graph) of the Serial Monitor. To use the Serial Plotter, go to Tools –> Serial Plotter. The graph below is the output of the LED as a light sensor from Project 3!*

The plot will auto-scale and as long as you’re using Serial.println() for your sensors, it will also print all of your sensors in different colors. Hooray! That’s it!

*If you look at the end, there is a super interesting wave pattern which is likely due to the Alternating Current (“AC”) in our overhead lights!

Visualizing Data: Excel!

For more serious data analysis, there’s a super cool (and free!) add-in for Excel called Data Streamer*, which you can download here.

This add-in reads from the serial port, so we can use the exact same coding technique of printing data to serial to get data directly into Excel.. heck yes!!

How to use the Data Streamer Add-In:

1. Once you’ve installed it (or if you have O365), click on the Data Streamer tab (far right) in Excel.

2. Plug in your Arduino and click “Connect Device”, then select the Arduino from the drop-down menu.

3. Click “Start Data” to start data collection! You’ll see three new sheets open up: “Data In”, “Data Out”, and “Settings”.

Live data is printed in the Data In sheet.  Each row corresponds to a sensor reading, with the newest value printed in the last row.

By default we only get 15 rows of data, but you can change this by going to “Settings”. We can gather up to 500 rows (limit is due to Excel bandwidth — there’s a lot happening in the background!).

 

4. Add a Plot of your data! Do some data analysis!
Scatter plots show you how the sensor readings change over time, which is the same thing we saw in the Arduino Serial Plotter.

To add a Scatter Plot:

Go to Insert -> Charts -> Scatter. When the plot pops up, right click on it and choose “Select Data”, then Add. We want our data displayed on the y-axis, with “time”** on the x-axis.

To do this, click the arrow next to the y-axis, go to the Data In sheet, and select all of the incoming sensor data.

We can also do calculations and comparisons in Excel! To write a formula, click on an empty cell and type an equals sign (“=”), then the calculation you want to do. There are lots of built-in commands like average, maximum, and minimum.

To use a command, type the equals sign, the command name, and an open parenthesis, then select the data you’re analyzing and close the parentheses.

5. To send more than one column of data (AKA more than one sensor), print the values on the same line separated by a comma, with a final blank new line, like this:

Serial.print(sensorReading1); 
Serial.print(","); 
Serial.print(sensorReading2); 
Serial.print(","); 
Serial.println();

*Full disclosure: Although this tutorial is not affiliated, I do work w/ the Microsoft Hacking STEM team which developed this add-in.

**If you want the actual time to be on the x-axis, select the timestamp in Column A on the Data In sheet for the x-axis values in your Scatter Plot. Either way, we’ll see our data as it changes over time.

Go Forth and Measure All the Things!!

Alright folks, that’s all! Time to go outward and upward! Use this as a foundation to start exploring sensors, Arduino coding, and data analysis to tackle your questions, curiosities, and fav mysteries in this big, beautiful world.

Remember: there are lots of folks out there to help you along the way, so please leave a comment if you have a question!

Need some more ideas? Here’s how to make a wearable state change switch, a solar-powered remote temperature sensor, and an Internet-connected industrial scale!

Like this tutorial and want to see more? Support our projects on Patreon! 😀

Renewable Energy Technology: What is it and How to Use it!

Now more than ever, folks like you and me have to step up and take a stand to protect and preserve our environment (and, quite honestly, our species). One great way to do that is to incorporate renewable energy technology into projects that use electricity.

Even if the environmental aspect isn’t enough to get you on board, you should still use renewable energy tech because the simple truth is that eventually we will run out of coal and natural gas. Besides, renewable energy tech is cleaner and more cost-effective in the long term, AND it means that you rely less on external sources for electricity — super handy in case there’s a severe storm or a solar flare that temporarily knocks out your local power grid.

First of all, what is renewable energy technology? Basically, it encompasses any technology that generates (electrical) energy from effectively renewable sources. For example, from our perspective, the sun is essentially an infinite power source since it will be around long after we are gone and produces more energy than we could possibly hope to consume in our lifetime.

Coal and natural gas are NOT renewable because they are finite, meaning that there is only so much of it available for us to use. Once we’ve used it up, we’re pretty much sh** out of luck, as the saying goes.

Now that I’ve convinced you it’s a good idea to use renewable energy technology, what are your options and how do you actually go about incorporating them into your projects?? Well my friend, read on to find out! This is by no means an exhaustive list, but it does cover the most common and easily accessible types of renewable energy tech.

Also, this guide assumes you have a basic knowledge of electronics, so please ask if there is a term or concept that you’re unsure about and I’ll be happy to expand or provide you with more thorough resources. Happy building!!

Photovoltaic Panels (aka Solar Panels)

Solar panels are awesome! I put these first because they are one of the most common and, in my opinion, the easiest to incorporate into all kinds of different electronic projects.

How Solar Panels Work

Solar panels convert incident radiation (aka sunlight) into usable electrical energy via the photoelectric effect. Basically, a photon (light carrier particle) knocks into an electron and transfers its energy to the electron. By making solar panels out of special materials called semi-conductors, one with extra electrons and one with missing electrons (aka “holes”), the free electrons are attracted towards the positively charged material (and repelled by the negatively charged material). When an external load is connected across the solar panel, it creates an effective current.

Since the current output depends on the amount of sunlight hitting the panel, the highest power output occurs when the panel is in full, direct sunlight (and is free of dust and debris).

How to Use a Solar Panel

  1. First, solar panels output Direct Current (“DC”), which is ideal for computer/microcontroller projects. For household applications, you’ll need an inverter to convert the DC voltage into AC.
  2. Second, since we’ll only get energy generation during the day, we’ll (most likely) need to use a rechargeable battery to store the energy for use at all hours of the day and night. Calculate the battery capacity that you’ll need by multiplying the electric current consumption of your project by the number of hours it will be on and consuming power without any external charge. For example, if my project consumes 0.20 mA of current and I want it to be able to provide power all night (~ 12 hours), I’ll need a battery with a minimum capacity of: 0.20mA * 12 hours = 0.0024 Ah (2.4 mAh). Also, the battery voltage needs to be lower than the solar panel voltage for current to flow from the panel into the battery.
  3. Third, use a diode for trickle charging or a charge controller for higher power applications to protect the solar panel from backwards current flow.
  4. Finally, to choose the right sized panel, figure out how much power your project consumes (P = I * V) and pick a panel within a reasonable range. For example, the power consumption of a 5V, 0.50mA microcontroller is 0.0025 W, so a panel between 1W and ~ 7W would be more than sufficient. For larger power panels, be sure you have sufficient circuit protection to avoid blowing out your microcontroller or other electronic device(s).

For more information, here is a helpful guide.

Wind & Water Turbines

Wind and water turbines use pretty much the same mechanism to generate electrical energy, so I lumped ’em together. Of course, depending on what medium you’re using, you’ll want a different turbine size and shape.

How Turbines Work

Turbines are a mechanical device that rotate when an external fluid passes through the blades of the turbine, whether it’s water or wind (whoa what air is a fluid?! yes, yes it is :D). The turbine is connected to a drive shaft that spins an electric generator to produce electrical energy. 

How to Use Turbines

  1. Turbines are location dependent, so first you’ll want to figure out if it’s feasible: Do you have a stream, waterfall, or other moving water source nearby? Does the location of your project get steady wind?
  2. Turbines also output DC current, so you’ll need an inverter for household appliances.
  3. As with solar panels, you will likely want a rechargeable battery to store the power for use anytime during the day or night, regardless of weather conditions. Calculate your needed battery capacity using the same method as for solar panels.
  4. Use a diode for low-power projects and a charge controller for larger projects to protect the energy generator from backwards current flow.
  5. Determine the power output for your turbine by calculating the power consumption of your project in the same way that’s outlined for the solar panel.

There are tons of DIY wind turbine projects on the interwebs, including on Instructables! Find one that fits your project needs and try building your own!! 😀

Here’s a link to more information on wind turbines!

 

Thermoelectric Generator

Thermoelectric generators (“TEGs”) are super cool, but generally have a very low power output. That said, they are not weather dependent, don’t have any moving parts (aka are essentially maintenance free), and are very reliable. Thermoelectric generators can be super handy for small projects like charging smartphones or powering LEDs.

How Thermoelectric Generators Work

Ok, so these things are somewhat complicated — basically, special materials with high electrical conductivity and low thermal conductivity can generate an electric current when there is a temperature gradient (aka a temperature difference between one side and the other). So if you heat one side of the thermoelectric generator and cool the other side, a current will flow. It also works the other way around — if you apply a current to the generator leads, it will cause one side to heat up and the other side to cool down.

A super simple thermoelectric generator is shown in the photo above: a junction of two different metals (copper and iron) is heated to produce a current output between one end of the copper wire and the head of the nail. It’s too little current to be of much practical use, but it’s a great educational project!

How to Use Thermoelectric Generators

  1. Another DC electrical energy generator! Get at those inverters for AC power applications.
  2. Since these are super low power, I’d suggest a rechargeable battery just like with solar panels and turbines, and maybe even an amplifier like a transistor.
  3. Since these will likely stay low power, you shouldn’t need a diode to protect the TEG, but be sure to have adequate circuit protection for your particular electronic load.
  4. You can purchase TEGs that have specific power outputs, typically for camping purposes, or you can rig up your own using peltier junctions. Consider connecting a few in series to get a higher energy output.

Here’s a great overview on how TEGs work, check it out and be inspired!

 

Other Types of Renewable (& Clean) Energy Technology

Ok, so that’s it! We’ve covered 3 of the primary renewable (and clean) energy technologies! There are TONS more out there but they are either 1) super involved, 2) super expensive or 3) both. Here are two of the more common ones to give you a sense of what is possible in the wonderful world of renewable energy technology!

Geothermal Power Plants

Geothermal power plants use hot water deep in the earth to run a steam turbine. This requires ridiculously deep wells (~ 1km) to pump up the hot water, run it through a heat exchanger (or directly through a steam turbine if you’re lucky enough to be close to a water source that hot), and then push the water back into the earth or let it seep back down naturally.

These are super cool because there are no negative consequences of energy generation — no pollution is generated (only steam!), no water is lost, and it the water will heat back up naturally over time.

Nuclear Power Plants

These are a bit controversial due to the radioactive waste byproducts of nuclear fission, but nuclear power plants do in fact generate renewable, clean energy. As long as the waste is properly stored and there are safeguards in place to prevent meltdowns, nuclear power plants are relatively safe and well understood.

Currently, nuclear power plants use the process of fission, which involves breaking up an unstable atom (e.g. uranium) to get out high energy electromagnetic radiation (aka light). That energy is usually converted into heat and used to run a steam turbine.

Ideally, we’ll figure out fusion somewhere in the near future, which is the process of fusing two simple atoms together (usually two isotopes of hydrogen). Nuclear fusion generates electromagnetic energy and inert particles like helium. This is what stars do! Except they are much, much more efficient as they are insanely hot and high pressure.

Fusion does NOT produce any radioactive waste, so it would be a perfect solution to our energy crisis. Now to just figure out how to get a net positive energy output….

For more info on fusion, check out this awesome article by the folks at Industrial Quick Search Directory.

Go Forth & Build!

Now you know what renewable energy technology is and, generally speaking, how to incorporate it into your personal projects. It’s also a great way to charge your gadgets while out and about, make your projects portable, and have a backup power source in the event of a power outage.

Please feel free to ask any and all questions! My goal with this is to empower you to feel confident in using some sort of renewable energy tech in your everyday life, whether you purchase it or build your own.

Remember, it’s ok (and encouraged) to start small and simple! Use a solar panel to power a small motor, use a wind turbine on your bike helmet to power a bike light, or use a thermoelectric generator to light up some LEDs while camping!

If this tutorial inspires you, I’d love to see any projects you made, share ’em in the comments below!!

Make Custom (& Inexpensive) Circuit Blocks!

Create, build, and play with your very own LEGO-inspired circuit blocks! Explore the basics of electricity and circuits, discover how sensors work and use ’em to design your own experiments, and incorporate upcycled materials to improve on your materials-sourcing & MacGuyver-ing skills! That old gum wrapper? Make it into a resistor or a switch!

But seriously, this is a super fun (and inexpensive) project/toy/game to teach electronics to kids (and adults!) of all ages and experience levels. The total cost of this project is under $30 and it takes about 2 hours to design and build.

 

Ok.. so where do we start?

First we need a base, the circuit block itself. This design uses breadboards* as the circuit block bases. I chose mini color breadboards so that each color denotes a specific type of electronic component (see next section). These are super cheap, typically less than $1 per board. Follow my design or create your own!

For each breadboard/component, we also need at least two or more breadboard wires (or 22 or 24 stranded wire), so for 20 breadboards with a single component we need 40 or more breadboard wires.

*Breadboards are non-edible, inexpensive prototyping boards for electronics projects. See photo above for a quick illustration of how breadboards work, or check out this tutorial.

 

Gather Electronic Components!

If you happen to have an assortment of electronic components around, gather them up and go through them to find the most choice pieces — we want components with only two leads, like simple motors, fans, LEDs, resistors, capacitors, etc. Check out websites like SparkFun or Amazon and search for electronic components.

Hey, wait, where can I get this stuff for free??

Dig up that box of broken electronics in your garage and see what you can find inside the electronics!

The best sources for components are electronic toys that move and/or make noise, speakers, telephones, and other medium-sized electronics.You’ll need wire cutters and pliers to remove the pieces, be sure to keep the legs intact so they can easily connect to the breadboard.

Avoid smartphones, tablets and laptops since the circuit components are suuuuper small and difficult to attach to a breadboard (unless that’s what you’re going for, then extract away!). For safety reasons, avoid appliances (e.g. microwaves, televisions, refrigerators, etc.), and do not use capacitors that are larger than a child’s thumb.

 

Build the Circuit Blocks!

The breadboard assortment I got included red, blue, white, green and black, mini breadboards. I broke up the colors into the following categories and components:

 

Red boards (power devices): One 1 W solar panel, one 9V battery clip, one 2 AA battery box, and two coin cell cases.

 

 

 

Blue boards (simple active): one motor w/ propeller, six LEDs of different colors (three per board), and one transistor (the transistor is pretty tricky — I’d recommend replacing this with another motor).

 

 

 

Green boards (sensors): one photoresistor, one buzzer/piezoelectric sensor, one peltier junction, and one capacitive sensor (this didn’t end up working, so replace it with a pressure sensor or other cool, two-lead sensor).

 

 

 

White boards (simple passive): six resistors of varying values (three per board), two (small electrolytic) capacitors of different values, and one potentiometer.

 

 

 

 

Black boards (electromechanical): Two pushbutton switches of different sizes/types (one per board), two toggle switches (single board), and one cooling fan.

 

 

 

To build each circuit block:
Connect each component to the first rows of each breadboard (be sure they aren’t shorted — should be on either side of the breadboard), and hot glue the wires into place. Remember to label which side is positive and which side is negative! Another fun option is to make labels for each component.

 

Plug & Play!

You’re ready to start building circuits and teaching other people the basics of electronics! Start simple, then add in more components to explore their function and see how they affect your circuit.

Here’s an example progression exploring different ways to light up an LED:

1. Use a coin cell to light up an LED.

Exploration questions: Does orientation matter? Where do the wires need to connect to the breadboard?

2. Use the solar panel to light up an LED. Move the panel into the shade (or cover it with your hand), and see how the LED brightness changes.

Exploration questions: How does the brightness of the LED change when you cover the solar panel? Why does this happen?

3. Use a coin cell and potentiometer to adjust the brightness of an LED.

Exploration questions: What do you notice? Does it matter how we connect the potentiometer?

4. Use a coin cell and a photoresistor to adjust the brightness of an LED.

Exploration questions: What do you notice?. Does it matter how we connect the photoresistor? How could we use the photoresistor in an experiment?

Build your own sequences to teach folks about specific circuit components or sensors, or use them as a fun & educational free-time project!

Make a Light-Up Holiday Card!

Light-up cards incorporate two of the best worlds of making (electronics and crafts) with the added bonus of making somebody smile. Heck yes!

Here’s my approach to light-up cards and my favorite recent discoveries: pop-ups and cotton balls.

Read time: ~ 5 min.

Build time: ~ 30 min -1 hr (mostly crafting the card)

Cost: < $5

 

Materials!

Gather up the following materials:

  • One or more LEDs!
  • Copper tape (~ 20″)
  • One coin cell
  • One paper clip
  • One pushpin
  • Colored paper
  • & any other craft materials your creative heart desires!

 

Build the Circuit!

 

 

1. Cut out a pocket for the coin cell.

 

 

 

2. Add copper tape to cardstock!

Stick 2″ of copper tape just above the battery pocket, so that the bottom of the battery rests on top of it. This is the negative (-) side of the circuit.

Stick another 2″ piece of copper tape on the underside of the pocket, so that it touches the top of the battery. This is the positive (+) side of the circuit.

 

3. Add a switch!

Cut a small line at the end of the copper tape, push paper fastener through the slit and hook the paperclip under the paper fastener (it might also help to add copper tape to the end of the paperclip). This makes an “on/off” switch!

 

 

4. Connect the LED!

The longer LED leg connects to the positive side of the circuit. The shorter leg connects to the negative side of the circuit. Be sure that these two sides of the circuit do not cross, or it “shorts” the LED and drains the battery.

 

 

Design & Make the Card!

1. Plan out where the light is going to go!

This is super crucial if you want the light to be in a specific spot, like the top of a tree, as a nose, etc. It’s helpful to make a super simple drawing of what you want before you try, or at least have extra materials on-hand for second (or possibly third) versions. Check all the things before you glue stuff down.

2. Craft the card!

Since it’s the December holiday season, I’m making a bunch of holidays cards for friends, woo! I like incorporating re-used (or upcycled) materials, so for this card I cut out the cover of an old calendar and folded the edges under to make it 3D (oooohhh now we’re gettin’ fancy!).

Another fun option are pop-ups! Cut out thin strips (~ 1/2 inch) and fold them accordion-style, then use ’em to prop up your cutouts and drawings!

3. Add in the LED!

You can either hide the circuit under the cover, or inside the card. For this card, the circuit slips under the cut-out, and the LED, covered by a lot of cotton balls, sticks out the top to light up the clouds!

 

 

Final Touches & Beyond!

Close the switch to the LED and stand in awe at your awesome creation! Write a heart-felt note on the inside and give it to your favorite family member/friend/coworker/neighbor/etc!!

There are tons of other ways to make the LED circuit! The photo to the left shows a method using magnets (ohhhh magnets!). What other ways can you come up with to make the circuit? Post your creations in the comments below!! 😀

How to Use (and Choose) a Multimeter!

Checking your car battery life, debugging circuits, and finding that pesky short are all super useful functions that can be performed with just one awesome tool: the multimeter!

First of all, what the heck is a multimeter??   Excellent setup question! It’s a handheld device with bunch of different electrical meters — hence, multi-meter!

Measuring voltage, current, resistance, and continuity (aka electrical connection) are the most common uses of a multimeter.  Read on to learn what this means, how to do it yourself, and how to choose your very own multimeter!

Choosing a Multimeter!


There are a few key differences between multimeters, the main one being analog versus digital:
Analog multimeters show real-time changes in voltage and current, but can be difficult to read and log data.

Digital Multimeters are easier to read, but may take some time to stabilize.

There are also auto-ranging multimeters, that automatically detect the measurement range, and manual ranging multimeters where you have to choose a range yourself (or start with the highest setting and work down).

Other than those two main differences, you’ll want a multimeter that has separate ports for current and voltage measurements (this is a safety issue, both for the meter and for yourself).

Next comes the fun part: features! Multimeters all have voltage and current meters (otherwise they’d just be called voltmeters and ammeters!), and most can also measure resistance. There are a variety of other “extra” features depending on manufacturer and cost (e.g. continuity, capacitance, frequency, etc.).

Second-to-lastly, there are a ton of different types of probe leads, including alligator clips, IC hooks, and test probes. Can’t decide? Here’s a kit that has four different types!

Lastly, always check the multimeter maximum voltage and current ratings to be sure that it can handle what you want to use it for.

Using a Multimeter!

But first! A quick overview of voltage, current and resistance!

My favorite analogy for electricity is the “water flowing through a pipe” analogy. In this analogy, voltage is similar to the water pressure, current is like the water flow (except with current you have electrons instead of water molecules!), and resistance is akin to the size of the pipe. Check out this tutorial for an awesome and thorough overview of electricity.

Keeping these analogies in mind helps us to figure out how, and what, we are measuring.

Measuring Voltage:

A voltage measurement tells us the electrical potential, or pressure, across a particular component.

Voltage is basically the “oomph” in our circuit, s so we want to avoid drawing any power from the circuit when we take a voltage measurement. This means we need to measure voltage in parallel with a particular component using infinite (or really, really high) resistance to prevent any electrical current from flowing into the meter.

Using a multimeter to measure voltage across a component (or battery!):

1. The black multimeter probe goes into the COM port, and the red probe into the port marked with a “V”.

2. Switch the dial to the “voltage” setting (choose the highest setting if you have a manual ranging multimeter).

3. Place black probe on negative side of the component, and red probe on positive side (across, or in parallel with the component). If you get a negative reading, switch the leads (or just note the magnitude of the voltage reading).

Read the meter output and you’re done! Not too bad 🙂

Measuring Current:

Taking a current measurement tells us the amount of electricity flowing through a given component or part of a circuit.

To measure current, we need to measure all of the flow in our circuit without consuming any power from the circuit and reducing the current measurement. This means we measure current in series with a component and we want our meter to have zero resistance.

Using a multimeter to measure current through a component:

1. The black multimeter probe goes into the COM port, and the red probe into the port marked with an “I” or an “A” (or “Amp”).

2. Switch dial to the current setting (choose highest setting if you have a manual ranging multimeter).

3. Connect red probe to current source, and black probe to the input of the component, so that the current flows from the source, through the meter, to the component (in series with the component).

Read the meter output! If you’re not getting a reading, switch to a lower setting.

Measuring Resistance: 

Measuring resistance is pretty straightforward, but you do have to disconnect individual components from a circuit to get their actual resistance, otherwise the rest of the components in the circuit can interfere with your measurement.

Using the multimeter to measure resistance of a component:

1. Put the black probe in COM port, and red probe in the port marked with a “Ω” or “Ohm” — it should be the same port as the voltage port.

2.  Switch dial to setting marked with a “Ω” (may have to choose approximate range for manual ranging multimeter).

3. Place probes on either side of the component (orientation doesn’t matter).

Read the meter output and you have conquered resistance!

Bonus: Measure Continuity!

The continuity measurement checks if two points in a circuit are electrically connected, otherwise known as a conductance test. Before measuring continuity, be sure that the circuit power is OFF.

Using the multimeter to measure continuity: 

1. Place black probe in COM port, and red probe in voltage port.

2. Switch dial to setting marked with an audio symbol.

3. Place probes at points you want to check — if the meter makes a beep sound, it means the two points are connected.

Le fin!

Go forth and measure all the things!

Now that we know how to use a multimeter, get crackin’ on all those at home, DIY projects! To get you started, here are a few quick, practical, & fun projects:

1. Measure the resistance of your skin! Change the distance of the probe leads and see how resistance changes. Lick your fingers (or dip them in water) to see how moisture affects resistance!

2. Measure the voltage across AA, 9V, or other batteries around the house/workplace/school to locate dead, or dying, ones.

3. Make a lemon battery and measure the voltage and current output.

4. Use the continuity setting to check if different materials conduct electricity.

 

Looking for more info on multimeters?

Check out this in-depth guide by the folks at Tools Critic!

Interactive Survey Game!

A survey questionnaire come to life! Use (nearly) any object to gather helpful data through an interactive, engaging, and fun multiple-choice survey.

This project uses the Makey Makey microcontroller in combination with a Raspberry Pi computer to read in participants’ survey choices and save the results in a text file.

Planning & Design!

This general design is easily customized to fit a different theme. The only crucial design requirement is to use materials that conduct electricity for the survey pieces, or wrap non-conductive materials in aluminum foil.

Suggestions:
Prototype, prototype, prototype! Build different versions and test them on family, friends, co-workers, or (ideally) your target audience. Observe how folks interact with your survey, then use that to make it better! And always remember to keep it simple 🙂

Materials

Makey Makey Kit
– Computer: Raspberry Pi

– One (1) ground piece, five (5) survey response pieces, one (1) submit piece, and two (2) yes/no pieces*

22 Gauge (stranded) Wire — five (5) 10 – 16″ strips and three (3) 6″ pieces (ends stripped)

– Container:

— Wood Box (12.5″ x 12.5″)
— Plexliglass.(“12 x 12”)
— Three (3) 2″ x 2″ wood panels

* Specific materials used in this design are detailed with the corresponding procedure, although customization is encouraged!

Tools

Safety goggles, woo!
Multimeter
— Optional: Soldering iron, solder& desoldering wick
— Ruler (or calipers)
Drill w/ both drill and driver bits
Flat wood file (to prevent splinters!)
Hot glue gun
— Epoxy (permanent)
– Pliers

Reprogram the Makey Makey

To reprogram the Makey Makey, you’ll need to have the Arduino IDE with Makey Makey drivers installed. Here’s a thorough tutorial on how to do this.


1. Plug Makey Makey into computer and open the Arduino IDE.

2. Open (or copy) Makey Makey source code:
Here’s the GitHub page for the Makey Makey.
Here’s a direct link to download the full program. This is a .zip file, so be sure to extract all the files.

3. Reprogram the “click” key into an “enter” key.
For a thorough overview of how to do this, check out this tutorial.

4. Change the following keys:
These two keys are mapped in the survey program, but can be left as-is or you can choose to switch other keys (e.g. the arrow keys). Just be sure to change the mapping in the program.

A. Change the “g” into an “n”.
B. Change “space” key into “y”.

Build the Survey Response Pieces!

Specific materials used in this design:

– Two (2) wood blocks, two (2) golf balls, and one (1) jar lid.
– Aluminum foil
Unistrut 1/2″ Channel Nut with Spring
– Ten (10) 1/2″ washers
– Plexiglass [or wood] (12″ x 12″)

Procedure:

1. Wrap each of the survey response pieces at least 2 – 3 times with foil, hot gluing each layer.

2. For unistrut spring pieces, hot glue (or epoxy) the top of the spring to the bottom of each survey response piece — be sure that the metal of the spring is touching the foil of the survey piece.

3. Attach the survey pieces to plexiglass.

Determine location of survey response pieces and mark with tape. Drill a hole at each point.

Place a washer on either side of the hold and screw bolt into unistrut spring about 3 turns.

4. Connect a wire to each of the unistrut spring pieces.

Wrap wire around base of bolt (between washer and plexiglass). Hand tighten the bolt to secure wire without squishing it

Build the Ground Piece!

Specific materials used in this design:
– Styrofoam ball
– Metal pipe
– Flange stand for pipe
– Aluminum foil
– Twelve (12) washers
– 4 wood screws
– Wood panel (2″ x 2″)

Procedure

1. Build a stand for the styrofoam ball — use conductive materials or wrap pieces in foil.

2. Wrap styrofoam ball in aluminum foil, leaving a “tail” of foil. Place ball on stand and push the foil tail against the inside of  Hot glue pieces together.

3. Cover the exposed end of the ground wire (24″) to the inside, or bottom, of base and adhere with tape or epoxy.

5. Add a layer of two (2) washers under base to avoid squishing the wire, then connect base to wood pane via screws or epoxy.

Build the Enter Key!

Specific materials used in this design:

– Clothespin
– Wood panel (2″ x 2″)
– One (1) wood screw + one (1) washer

The screw should be about 1/4″ longer than the wood thickness.

– Aluminum foil

Procedure:

1. Wrap one of the handles of the clothespin in foil.

2. Remove clothespin spring clamp, align other side of the clothespin on wood panel, and drill in a screw and washer.

Foil on the other side of the clothespin should make contact with the washer + screw when closed.

3. Reconnect spring clamp and other side (may need pliers). Epoxy bottom of clothespin to wood panel.

4. Use alligator clip or wrap wire around screw and secure with hot glue.

Make the Yes and No Keys! 

Specific materials used in this design:
– Two (2) plastic container lids
– Two (2) wood panels (2″ x 2″)
– Two (2) wood screws and washers

Each screw should be about 1/4″ longer than the wood thickness.

– Aluminum foil


Procedure

1. Cut circle out of container lids. Wrap in foil.

2. Align lids on wood panels and drill in a wood screw with washer on top — be sure the screw slightly pokes through the back of the wood panel.

3. Use alligator clip or wrap wire around screw and secure with hot glue. 

Connect Pieces to Makey Makey

1. Connect ground piece lead to Makey Makey ground pads.

2. Connect survey game pieces to the first five (5) Makey Makey back header pins on the left: “w”, “a”, “s”, “f”, and “d”.

3. Connect the no button to the last (6th) back header pin, “g”

4. Connect the yes button to the “space” pads.

5. Connect the submit piece to the “click” pads.



Load the Survey Program!

Using a Raspberry Pi computer means that all of the electronics can fit into the game box! Write up a program in Python to cycle through a series of survey questions and five possible choices that map to the survey response pieces.

Here’s my code:
GitHub page!
Python program only.

Final Touches & Case!

This case is designed to withstand high traffic, experimentation, and children — and to be easily (and cheaply) fixable and adjustable. Use this design or customize your own!

Materials:
12.5″ x 12.5″ wood box
1″ x 10 ” wood panel

Procedure:
1. Epoxy wood panel onto front of box.

2. Drill the submit, yes, and no keys into the wood panel.


Recommended to put the “submit” button on the far right (switched this after further testing and feedback).

 

3. Drill hole large enough to fit an HDMI port in the back panel of the box.

I used two 3/8″ bits and filed down the hole until the HDMI port fit.

4. Label the survey game pieces and the submit, yes, and no keys.

Test, & Install!

Connect the Raspberry Pi to a monitor, keyboard, and the Makey Makey. Test the program and double check all the keys. Once everything is up and running, remove the keyboard (and mouse if connected).

Load the python program, stand back, and let passersby have a blast participating in a survey!

Prototyping Magnetic Boots!

Walking across large, metal pipes in search of urban adventure, my inner voice joked, “Hey, magnet shoes would be handy right about now.” Well, no arguing with that! Off to build my very own magnetic shoes!

This tutorial gives an overview of my build process for a magnetic boot prototype in hopes of inspiring you to build and test your own whimsical ideas! ‘Cause seriously, making ideas come to life feels like a superpower.

 


Materials


— Sturdy Boots
These had to secure my feet (aka no slipping out) and withstand my body weight. I found a pair of sturdy (although rather large) snowboard boots at a local thrift store which work as a first prototype.

— Rare earth (neodymium) magnets
Small, thin-ish (< 1/4″ thick) magnets with a 10 – 15 lbf rating (see previous step).

— One screw per magnet (or per magnet hole)
Use screws with a length shorter than the sole of the shoe (so they don’t poke your lil’ feetsies.. or add some sort of rubber sole inside).

— Suggestion: One washer per magnet
Supposedly, the washer helps increase the magnetic field of the exposed surface. I haven’t calculated this or done any serious research, so at this point it’s just a design suggestion.


Tools



Drill

— Ruler

— Pen/pencil.

CNC Router and a 3/4″ drill bit

 


Build Process!



1. Level bottom of the boot with a CNC router (or other available method).

Clamp the boots to the CNC table with the bottom facing up — a piece of wood was helpful to keep the boots straight.

Set the zero point of the CNC to be the lowest point on the sole of the shoe, then use a large bit (ours was 3/4″) and level the sole of the shoe to the zero point.




2. Mark boot with tape for location of magnets.



3. For each magnet, drill in screw, magnet, and washer into the bottom of shoe.


Testing!


To test the boot, I stuck it on a roof beam and pulled downwards. I added more magnets and repeated this until I couldn’t pull the boot off by hand, then (slowly) tried to hang from it.

Lessons learned during testing:
1. I ended up using waaay more magnets than I thought, so it is probably worthwhile to calculate how the individual magnet fields are adding together.

2. Magnets need to be level to maximize the total magnetic field strength.

3. There is a limit to how close you can place each magnet depending on the shape and size of its magnetic field. Smaller, round magnets are easier to work with than large, rectangular magnets.

4. Don’t place magnets close to parking passes (or other electronic devices). Also keep them far, far away from large containers of screws.


Results & Next Steps!


At this point, my magnetic shoes are more magnetic “gloves” (lol thanks @jayludden :D). But! I can successfully hang from one boot, so the concept works!

The lessons learned from testing will help improve this prototype design. Currently awaiting more magnets for the second boot (used most of them for the first one), trying different magnet orientations, and searching for a spot to test them upside down.

Stay tuned, will have them up and running, er, well, hanging, soon!

Many thanks to: Tinker Tank at Pacific Science Center for being my build and test center, and to Richard Albritton for the CNC help!