Introduction: Simple Electronic Piano With 555 Timer in CD Case

About: Master of Information Technology, Universitas Indonesia | SecOps Engineer | A Rhesus(+) | Aries | Photography | Arduino | Computer Geek | Art & Design
In this instructable, I will show you how to make a simple electronic piano with common components. It uses capacitors and resistors, so you could easily modify the circuit. When the project is finished you will have a working simple circuit that can produce a variety of tones.

Of course, there are a couple of instructables that already feature such a circuit, but this is an Electronic Piano similiar to the one designed by sholtob. For reference, the original sholtob article is here while a great tutorial on building it is here. For the enclosure I used an old CD case, so it will easy to hold, and to keep the circuit well.

This is the video of my electronic piano

Step 1: Parts and Tools

Here is all you will need:
- (1) CD case
- (1) Perfboard
- (1) IC 555 Timer
- (1) 8 Pin DIP IC Socket
- (1) Potensio 10K
- (1) Potensio Knob (optional)
- (6) Tacticle Switch / Buttons
- (1) Flashing LED RGB (optional colour)
- (7) Resistor 1K Ohm
- (1) Ceramic Capacitor 0,1uF
- (1) Electrolit Capacitor 10uF
- (1) Speaker 8 Ohm
- (1) 9 V battery
- (1) 9 V battery holder with switch / Battery Clip
- Shrink tubing
- Jumper wire
- Male header extended (optional)
- Blackhousing / female 1x1 header (optional)

- Soldering iron
- Solder
- Hot glue
- Mini drill
- Pliers
- Cutter
- Helping hands (if you don't have it, you can build it from my helping hands instructable)

Step 2: Making the Circuit on Breadboard

First, lets put the components on a breadboard so we could see how it worked and how to fit it onto the perfboard.
The circuit diagram was made with Fritzing.

Test everything out and make sure that you're circuit is going to work before you start soldering.

Step 3: Move to Perfboard

Step 1
Cut the perfboard about 1/4 of its original size.

Step 2
Create paths of the circuit using markers. (this step just for easier our work, and easier for troubleshooting the circuit)

Step 3
Arrange the tacticle buttons and the resistors. Use a jumper wire to connect the "first leg" button to "first leg" on other button.

Step 4
Soldering the buttons and the resistors.

Step 4: Complete the Circuit on Perfboard

Step 1
Pins 2 and 6 need to be connected together and then attach to the negative end of the buttons. The 0,1uF ceramic capacitor is also placed beside the two jumpers. The other lead from the capacitor is bent down and used to connect to another lead which is connected to ground.

Step 2
Pin 1 is going to ground. Pin 4 and 8 is going to 9v (positive).

Step 3
Attach the positive lead of electrolit capacitor to Pin 3, then the negative lead to positive header for speaker. I'm using male header (extended) for positive and negative of speaker. In case I want to replace the speaker with Stereo Female Jack Connector if I want to using my headphones. (I'll show you "how to" later)

Step 4
I'm using male header (extended) too for potensio, so it will easy to modify with other value. The first lead of potensio is going to the last resistor and second last button. And the other lead of potensio is going to Pin 7.

Step 5: Adding the LED and Power Wire


Step 1
Solder the resistor to the positive terminal and the other end to the positive lead of the led (the longer one). Then take the other lead and solder it onto the ground.

Step 2
Solder anode and cathode of LED with jumper wire and shrink tubing is essential to prevent shorting.
Twist the jumper wire, to make them rigid.

Step 3
Attach the LED with the circuit we've been built before. The positive lead of LED connect to resistor 1K, while the negative lead connect to the ground.

The led should turn on when the device is powered and the other function is LED will stop you forgetting to turn off the instrument.


Step 3
Build two blackhousing / female header 1x1 (for positive and negative)
1. Strip the end of the wire, about 0,5 cm
2. Put the wire in the slot of the blackhousing clip, and bend it around the striped end.
3 & 4 Place the clip into the blackhousing header.

Step 4
Solder the wire to each positive and negative section on the perfboard with the circuit we've been built before.

Solder components carefully to ensure there are no shorts, also ensure all connections are made at all points.

Step 6: Putting All Together

Now it's time to put it all together, attach the power wire, potensiometer, speaker, and check all your joints and work through the diagram circuit. Connect a 6 - 9v power supply, and press the buttons. Pressing the different combinations produces different tones. Moving the pot also changes the tones.

This video will show you how my circuit works after all joined.

Step 7: The Enclosure

Step 1
Drawing the pattern on CD Case with marker for placing the circuit, speaker and potensiometer. It's really helps for drilling.

Step 2
Be careful when you drilling the CD case, because it quite thin. You may get some crack, but it's okay as long as you didn't crack the whole case. For the button, you can tidy it up by using a small cutter knife.

Step 3
There will be some scratch and some little cracks on the case, I want to make it neat and nice looking, so I used a colour paper for covering the surface.

Step 8: Put the Circuit Into Enclosure

I attach the perfboard to the CD Case with 'Foam Double Sided Tape' instead of using hot glue, just in case I want to modify the circuit later. But if you want to make the circuit steady and permanent I recommend for using some hot glue.

And for looking better, I used a colour paper for covering the surface.

Step 9: Modify As You Want !!

This circuit is easy to modify as it's so simple, and there are some ways to modify the instrument :

1.  You could replace a resistor with a LDR to create a solar therimin, or change the resistor values to get different pitches

2. You could replace a speaker with stereo female jack connector, so you can use headphones to listening the sound.

3. You can add more buttons / LEDs if you want.

4. Adding a potensiometer between speaker and capacitor can help in tuning the piano.

5. Let your creativity flow!!

Have fun :D

Greetings from Indonesia!!

Pocket Sized Electronics

Participated in the
Pocket Sized Electronics