Introduction: How to Make a Musical Chair
The purpose of the musical chair was to make music whenever people touch each other, such as holding hands or kissing. Based off a previous project, I decided to recreate the musical bench project, using a chair instead.
Step 1: Materials
Bill of Materials:
- Arduino USB (any type will work)
- $ 24.95Sparkfun Musical Instrument Shield
- $29.95Arduino Stackable Header Kit $ 1.50
- Two 1k Ohm resistors $0.25
- One 39k Ohm resistor (you can use a 47k resistor from this set if you can’t find a 39k) $7.95
- One 0.1 uF capacitor $0.25
- Solid core wire (red, black, and white is optional color choices)
- Stranded wireTwo Touch Pads (you can use scraps of copper or brass, copper pipes, or other conductive objects)
- DC power supply 9-12V
- $5.95Speakers or headphones with ⅛” stereo jack
- bench or chair
Soldering iron (we like this one from Weller)
- A computer loaded with arduino software
Here are some helpful websites:
Step 2: Solder the Headers
Solder the header to the main board. Insert the pins of the headers into the round holes along the side of the Shield. Make sure pins are down and pointing away from the side of the shield with the components on it.Then flip the shield over and solder each pin to the round hole. Make sure the pins are straight.
Step 3: Add Your Resistors
Place the music shield right side up, where the text is facing you. Place the three resistors next to each other in the center of the prototype area of the Musical Instrument Shield. Place the 39k resistor on the left. Place one of the 1k resistors in the middle and the last 1k resistor on the right, nearest the audio jack.Flip the board over and solder each leg. Also wait to snip the ends of the legs.
Step 4: Add the Capacitor
- Flip the shield over again. Place the capacitor above the resistors, just on top of both 1K resistors.
- Flip the shield to the back, and solder the capacitor down.
- Solder a leg of capacitor to the adjacent end of 1K resistor, which is located in the middle.
- Solder the other leg of capacitor to the adjacent end of the 1K resistor on the right.
Step 5: Adding the Wires
- Now you will add three wires to the board. To keep them easily identifiable you may use different colors but you do not have to.
- Cut a piece of solid core wire about 2” long and strip both ends.
- Insert one end into board right next to capacitor and directly above the resistor, located on the left side.
- Flip over the board and solder that end into place. Bend down the leg of the resistor and solder it to the wire.
- Flip the board back to the front and insert the other end into the header socket labeled “AREF” (it is on the bottom left side of the shield).
- Cut a piece of solid core wire about 2" long and strip both ends about 3/8".
- Insert one end into the board just above the capacitor/ 1K resistor located all the way on the right junction. Flip the board over and and solder the end into place. Make a soldered connected to the adjacent the capacitor/ 1K resistor (on the right side) junction.
- Flip the board back to the front side and insert the other end of the wire into the header socket labeled "GND" (right above "AREF").
- Cut a piece of solid core wire about 3" long and strip both ends about 3/8". Insert one into the board just above the capacitor/middle resistor junction Flip the board over and solder the end of the wire in place. Flip the board over and Insert the other end of the wire into the header socket labeled "A0" (on the middle right side of the shield).
- The overall product should look something like this.
Step 6: Connect the Wires to the Touch Points
- Cut two pieces of the stranded wire as long as you will need to reach from the shield to where you want the touch pads to go.
- Strip back 1/4" on one and insert just below 1K resistor on the right. Flip the board over. Solder the wire in place and make a soldered connection to the leg. Go back to the front of the board. Strip back 1/4" on the other wire and insert just below 1K resistor thats located in the middle. Flip the board over. Solder the wire in place and make a soldered connection to the resistor(the one in the middle) and the other resistor (located on the left) junction.
- Now you need to connect the other ends of the wires to your metal touch pads. We soldered them but you can also use bolts, alligator clip leads, or any method you wish. You may want to experiment with different materials and sizes for touchpads using alligator clips before soldering the leads. I used a sheet of brass metal.
Step 7: Check Your Work and Mount the Shield
Check your work and then you can snip off the protruding legs.
Then you can mount the shield onto the arduino by plugging the stackable header pins into the Arduino's header sockets.
There may be more header sockets on the Arduino than on the shield, but it's fine. Those sockets will not be used, and if you look closely, you will see that, due to the gaps between headers, there is only one way to plug it in smoothly without bending any pins.
Check to be sure that the USB connector on the Arduino is not shorting out to the bottom of the shield. If it is, you may need to put some tape in between.
Step 8: Load the Sketch to the Arduino
Plug the USB into your computer and load the SingingSnack sketch on to your Arduino. If you need help with this go to the guide on the Arduino home page
Step 9: Exploring and Have Fun
Plug your headphones, earbuds or powered speakers into the audio jack on the shield.
Touch both pads and start exploring how different types of touch maps to different notes. If you hold one of the touch pads and a friend holds the other you can make music by touching fingers, etc.
Step 10: Tweak the Sketch
If you go into the sketch on the arduino there are a few variables that are fun to play with. We've labeled which variables are the most tinker-able and the ones are probably better left alone (unless you are an arduino master).
Here are some helpful hints:
#define SIXTEENTH_NOTE_MS (100) - this number changes the fullness and denseness of the arpeggio (a series of notes played in sequence). We've decided to use the arpeggio to make the sound amore "musical"
#define SENSOR_HYSTERESIS (10) - this variable defines how sensitive the device is to changes jn resistance. We dialed this down to 4 to get a more full sound (although it also can produce more 'noise' in the system).
#define LOWEST_NOTE (48)
#define HIGHEST_NOTE (96) - these two variable controls the range in notes that can be played although the highest and lowest notes are usually not used.
#define MY_INSTRUMENT (0) - it's set to the 'grand piano' instrument but it's fun to play around with the numbers (it goes up to 127 to create some interesting sounds and even percussive effects).You can also change the volume and "strike force" here if your headphones don't have volume control.
Step 11: Hack the Chair
There are many ways to approach this, but here are the steps that I used.
Either you can mount the arduino to the bench or find a box to hold the arduino and speakers. I mounted mine directly underneath the my chair.
From there, I placed two pieces of brass (or other conductive material on parts of the arm rest). *I used super glue to mount the two metal pieces. However, soldering can also be an option.
Then I ran two separate wires alongside the chair (so they are not visible) and connected them to my touch points from the shield.
Step 12: Keep Playing and Have Fun
Now that you have finished, feel free to experiment with the chair and people in order to create cool and unique sounds.