Build an (easy) Floor Piano!

The household floor piano is a dream no more! The Makey Makey microcontroller makes it super easy (and affordable) to build your very own “foot-strument” out of common household materials.

Grab a Makey Makey kit, some cardboard, and your musician shoes and let’s get building!

  • Difficulty Level: Easy
  • Estimated Build Time: 60 minutes
  • Cost: $50 (for Makey Makey kit)

 

 

Materials & Tools

Materials

  • Makey Makey Kit
    • 16 Breadboard Jumper Wires
    • 4 Alligator Clips
  • Cardboard
  • Aluminum Foil
  • Plastic Trash Bag (stretchy is best)
  • Duct Tape

Tools

  • Scissors
  • Hot Glue Gun
  • Measuring Tape or Ruler

 

Build the Piano!

1. Build the piano base.

Cut a cardboard base for your keyboard, then divide it into 8 equally sized rectangles — these are the dimensions for your piano keys!

2. Make the piano keys!

Cut out 8 cardboard rectangles using the base dimensions and paint them white.

3. Build the key triggers for the piano.

Cut 16 cardboard rectangles of equal size or smaller than the cardboard piano keys.

Repeat the following for each pair of key triggers:

  • Cover both cardboard rectangles in aluminum foil.

  • Use copper tape to connect one wire to the aluminum foil on each of the key triggers, then cover the connection in duct tape to secure.

  • Cover one of the rectangles with a piece of the plastic trash bag so that the aluminum foil is completely covered. Secure with duct tape.
  • Sandwich the two key triggers together so that the trash bag is a barrier between the aluminum foil.

 

Connect to the Makey Makey!

1. Connect the wires to the Makey Makey – one of the wires goes to ground and the other goes to a keypad (doesn’t matter which wire).

2. Test that the Makey Makey is triggered when you put pressure on the cardboard.

3. Tape the key triggers to the bottom of the white cardboard piano keys. Secure them to the piano base with velcro or glue.

4. Connect one of the wires from each of the key trigger to the six header pins on the back of the Makey Makey board and to two of the arrow keys on the front.

5. Connect the other key trigger wires to the Makey Makey ground.

Recommended to connect the ground wires in two groups of 4, then use one alligator clip per each group of 4.

Write the Scratch Program!

We have 8 inputs, which means we can play an entire octave on our floor piano! (Yes, that was intentional).

Your job: Write a Scratch program that plays 8 successive keys starting at middle C (or wherever you prefer your piano octave to start) using the “play note” function. Or you can copy mine in the photo above 🙂

Aside from the program, just be mindful of what piano key is connected to what Makey Makey pin. It’s easy to get 8 wires a bit mixed up — consider labeling them to save yourself some time (& hair..).

Install & Play!

Consider coating the electrical connections in hot glue. Plug the Makey Makey into your computer, place your floor piano on, well, the floor, and have at it!

Enjoy making beautiful music by stomping on your custom creation.

Build & Play Robot Mini Golf!

Introduction

Create, build, and play an obstacle course for Brush Bots! This is an activity for all ages that teaches the basics of circuits and design thinking while encouraging and inspiring creativity, discovery, and collaboration. Most importantly, it’s super fun! (But seriously though, watch the video it’s adorbs and will make you smile)

This tutorial will show you how to build (and source parts for) a Brush Bot, how to design and build mini golf inspired obstacles, and how to use the design thinking process to create a Brush Bot that can accomplish each of the obstacles. Go forth and build your own Robot Mini Golf course!!

 

 

Tools & Materials

Tools

  • Scissors
  • Hot glue gun(s) + hot glue sticks
  • Wire cutters/strippers
  • Masking Tape

Materials

1. Electronics

2. Brush Bot Body & Feet

Since there are tons of ways to build the body, no list is absolute. Here are some suggestions (upcycling materials are highly encouraged & also cut down on cost!):

  • Toothbrush bristles
  • Styrofoam/plastic/paper cups
  • Paper plates
  • Cardboard
  • Tupperware
  • Toothpicks and/or wooden skewers
  • Popsicle sticks
  • Styrofoam pieces

3. Obstacles

  • Cardboard, cardboard, and more cardboard!
  • Art supplies
  • And maybe throw in some electronics in there also (see Step 4) 🙂

 

What the heck are Brush Bots??

Brush Bots, or Bristle Bots, are the simplest possible form of a robot: a motor with a counterweight and a battery attached to simple body. The counterweight causes the motor to shake, which, in turn, causes the body to shake.

The name “Brush Bot” comes from
a common design that uses toothbrush bristles as the “feet”. The term has been adapted to refer to any simple robot based on the counterweight motor design. Another super fun variation are Art Bots, which use markers or other materials to draw while they wobble around!

There are tons of ways to build a Brush Bot. A couple of approaches are shown in the photos. What other ways can you invent to build a Brush Bot?

 

Building the Obstacles

My obstacles were inspired by mini golf and through my experience in teaching Brush Bots and seeing various approaches from students and educators. I wanted obstacles that would be fun, accessible, and interesting for kids and adults, so I came up with four obstacles of varying difficulty.

Obstacle 1: Enter the Arena

Starting from 1 – 2 feet away, the Brush Bot must enter the opening to an arena. This can be made by marking an arena with tape, or by building a simple fence from cardboard.

Obstacle 2: Spiral Maze

The spiral maze is a crowd favorite and is a great obstacle for younger kids to tackle. Build the spiral maze by scoring a long piece of cardboard (~ 4 feet), then gluing it in a spiral pattern on a 2′ x 2′ cardboard square.

I decorated mine to look like a galaxy by spray painting the outside gold and the inside black, then gluing glow-in-the-dark stars on the inside.

Obstacle 3: Ramp

Although easy to make, this obstacle has proved to be the most challenging. I recommend using a low incline (less than 15 degrees) and adding a rough surface (e.g. sandpaper) on top of the cardboard.

Build the ramp by cutting out two identical triangles and then adhering a cardboard square on top.

 

 

 

Obstacle 4: Robot Head

By far the most fun, but a bit more complicated. I wrote a quick Arduino sketch to move a servo motor and added an IR breakbeam switch to trigger some LEDs when a Brush Bot goes into the mouth.

Recreate or modify this Robot Head or create your own whimsical obstacle!

Building the Brush Bot(s)!

1. Dismantle and gut an electric toothbrush! Your mission: find the motor.

For the Assure-brand “Soft Bristle Electric Toothbrushes” that you can get at the Dollar Store (just $1 woot woot!), twist off the bottom, pull out the battery holder, and pull out the motor. You may need to tap (or hit) the open toothbrush on the floor to get the motor out, or (gently) use pliers to pull it out.

2. Grab (or build!!) a battery box, and connect the positive side (red wire) to one of the motor leads*.

3. Connect the negative side of the battery box (black wire) to the other motor lead.

Orientation doesn’t matter — try switching them and see what happens!

4. Design and build a body for the lil ‘bot and give it a way to move. Iteration through different designs is recommended and encouraged!

Some common and easy ways to make the Brush Bot move are to use toothbrush bristles, toothpicks, or popsicle sticks to make legs/feet. Try different objects and object placements to see what happens.

*The motor leads are those gold tabs with holes by the white cap of the motor.

 

Conquering Obstacles W/ Design Thinking

Design Thinking is a problem-solving method. Traditionally, it’s applied for design of hardware and software products in various engineering disciplines, but this process can be applied to pretty much any aspect of life. The Design Thinking process comes in variety of flavors, here is a common breakdown:

1. Design: Who is your audience? What, or who, are you designing for? What are constraints for your product/project?

2. Ideate: How can you solve this problem? Come up with at least 3 – 5 different approaches — impossible solutions are totally acceptable in this phase.

3. Prototype: Choose one of your (possible) solutions and build it.

4. Test/Observe: Test your prototype and observe how it behaves. Does it solve your problem? If not, what’s wrong with it? If it does, can it be done in a simpler or easier way?

5. Adjust: Change your prototype based on your testing and observations.

Repeat steps 3 – 5 until you’ve arrived at a solution that solves your problem, satisfies your audience (or teacher), and meets any design constraints.

For Educators:

You can go through the design thinking process before, during, or after the workshop. One of the benefits of having obstacles to conquer is that it motivates students to naturally go through this process without having to sit and think about it.

 

Compete & Add Prizes

That’s it! You’re ready to tackle and challenge your students, friends, and/or family to a game of Robot Mini Golf!

A bonus feature would be to add prizes for anyone who successfully completes either one or all of the obstacles. My favorite method is to give out small prizes (e.g. stickers or buttons) to anyone who builds a Brush Bot that completes at least one of the obstacles, and a larger prize for anyone whose Brush Bot successfully completes all of the obstacles. This is a great way to adapt this into a workshop for folks of all ages — older kids and adults can try to conquer all of the obstacles while the younger kids still get to participate and have a blast! 😀

Please feel free to share your Robot Mini Golf stories in the comments! Would lovelovelove to hear anecdotes of how this activity went with students and/or to see photos of your unique Brush Bot(s) and obstacle course creations!

A Few of Our Favorite Brush Bots

 

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!! 😀

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!

Portable Solar USB Charger

Portable USB chargers are incredibly useful for adventures in the great outdoors, festivals, traveling, or if you are out-and-about all day. Adding in a solar panel provides an additional source of portable power useable (nearly) everywhere.
The whole project can be built for ~ $20, even if you don’t have a soldering iron!

Parts

  • 1.5W Solar Panel 9V
    • Suggested to use a low-power solar panel, typically if you are not using a charge controller.  
    • Note that the solar panel voltage output MUST be higher than the battery output for it to actually charge
  • 1N914 or similar diode
    • This protects the solar panel by allowing current to flow only from the panel to the batteries (aka prevents discharge from the batteries onto the solar panel).
    • If you choose a similar diode, be sure it works w/ the given solar panel specs (voltage/current output).
  • USB car charger
  • Rechargeable 9 V battery**
  • Battery holder for 9V (or use alligator clips)
  • Project container (e.g. tupperwear, altoids tin, cookie tin, etc.). Be creative!

Tools

  • Wire strippers
    • Scissors also work. To strip the wire, make cuts on both sides and pull off insulation w/ your fingers.
  • Electrical Tape
  • 5-minute epoxy, or other similar adhesive (gorilla glue probably works)
    • Other methods for making electrical connections: twist wires together and coat in epoxy. Other connections can be MacGyvered together; take apart old electronics for connectors and wires, use paperclips, and be creative w/ conductive objects like pennies.
  • Multimeter, if available. Massively helpful for testing electrical connections and checking if the circuit works as expected.

Background Info

advenira.com
advenira.com

Solar panels are awesome for many reasons:

  1. Renewable energy technology, woo!
  2. Handy in remote locations (like Burning Man..).
  3. Lifetime of 25 – 30 years.
    etc.*
SOLAR-WIND.CO.UK
SOLAR-WIND.CO.UK

Solar panels, or photovoltaic (PV) panels, output direct current (DC). Digital devices, like cellphones or iPods, run on DC. This means our charging circuit is fairly simple. As in the photo on the left, we need a panel, a battery, and our device, or load. Charge controllers regulate current flow primarily to protect the battery. We can avoid using one in our USB charger, but they are ideal for larger systems.

The solar charging system works w/out the batteries. The batteries are there so you can use the system whenever you need it.

 

A lil’ bit about USBUSB_pinout

As shown in the photo to the right, USB chargers have 4 pins. All USB chargers output 5 Volts (V) DC on the USB Vcc pin. However, the amount of output current depends on the type of USB charger. There are three main types: a standard downstream port (500 mA), a charging downstream port (1500 mA), and a dedicated charging port (900 mA).

Apple USB is a bit trickier (unsurprisingly..); one of the data pins is set to 2.7 VDC. So, if you finish your portable USB charger and you want to charge an iPhone or iPod, you need to increase the voltage (aka use a bigger battery.. or two 9V batteries connected together in series.

Build ProcessSolar_USB_Charger

Note: if you are using the epoxy method for connecting wires, wait until after you’ve tested the whole system to coat w/ epoxy..  epoxy is rather permanent and once it is set there is little you can do besides curse at it (won’t really help, but might make you feel better!).

  1. Strip wire on end of solar panel (remove colored insulation to expose the metal).IMG_4626

    No leads on the panel and there’s no soldering iron?! It’s all good! Get creative.
    Here’s one way: tape two wires onto the metal pads on the back of the panel w/ electrical tape (colors don’t really matter, but convention is red = positive and black = negative). Test it w/ a multimeter, or by connecting the leads to the USB car charger to make the “charging” LED light turn on. Coat in epoxy, let dry & you’re done!
  2. Connect diode to positive end of solar panel lead. If possible, solder the two ends together. Otherwise, twist wires & coat in epoxy at the end. Super important: install the diode so that the side w/ the silver band is connected to the battery, like in the photo to the right.
  3. Connect diode to positive (red) side of battery holder. Connect negative (black) solar panel lead to negative battery holder lead.IMG_4643
  4. The front metal part of the USB car charger is the positive terminal. One of the metal side tabs is the negative terminal. Determine which side of the USB car charger is the negative (or ground) side.
    Here are a couple easy ways:
    — Open up the charger; see which metal tab is connected to a wire.
    — Use the panel to turn on the charger. Connect the positive battery/solar panel lead to the front metal lead. Touch the negative battery/solar panel lead to each side. The side that causes the “on” light to light up is the negative side.
    IMG_4580
  5. Connect the negative battery/solar panel lead to the negative tab on the USB car charger. Connect the positive battery/solar panel lead to the front metal lead on the USB car charger.
    There are a few ways to do this, depending on your available tools and materials. The easiest way is to use alligator clips (and coat them in epoxy when it’s all done & tested).
    IMG_4646IMG_4645
  6. Test it! Connect a USB device (like the Raspberry Pi!!) and make sure it lights up.
    If it works, epoxy all the electrical connections, put it into a container and take it w/ you on an adventure!
    Once your first version works, make upgrades and modifications as necessary! Google is super helpful.

IMG_4649

*More info about solar!

Solar panels have a relatively low energy efficiency rating, typically around 12-15%. Research is continually improving solar efficiency, and a lab in Germany set the world record for solar cell efficiency at 44.7%.

In 2012, average costs of solar per watt were between $1 – $2, with some as low as $0.70 per watt. Although this does not include the cost of additional equipment (e.g. batteries, transformer for AC applications, mounting system, etc.), it is beginning to seriously compete with fossil fuels. Yay, solar!!

**Why a 9 V battery?

USB car chargers expect 12 VDC from the car, but will accept between 6 VDC and 14.5 VDC. Using a single 9V battery is the easiest way to get a sufficient input voltage for this USB circuit in order to get an output of 5 VDC.