Arduino Plays Piano Tiles

by psurya1994

39K16333

Intro: Arduino Plays Piano Tiles

Ever wondered if your phone can play games by itself. Yes, it is possible. You can build a circuit to play Piano tiles on your smartphone.

The video shows the demonstration of the project.

STEP 1: Components Required

And the circuit can be built with simple components like Light sensors, Relays and Arduino.

Three main functions of the circuit are :
Sensing color of the tile (Black or White)Processing the color information and generating timing for the touch (Arduino)Simulating capacitive touch (Relays)

STEP 2: Sensing

We use light dependent resistors (LDRs) to sense if the tiles are white or black. Four LDRs are positioned over the screen each facing one tile. The LDRs have been connected to the back of the cardboard like this.

The LDR resistance changes with the intensity of Light. Higher the intensity of light, lesser the resistance. LDR is placed in a Voltage divider circuit to produce a voltage proportional to its resistance.The LDRs are connected to the analog input pins of the Arduino as shown.

Practically, this is how you would connect the circuit. You can check the test_ldr code to see if the LDRs are working fine. When you run the code, you will get a high value from the LDR if it’s sensing black, else you get a low value.

STEP 3: Processing

Arduino reads the voltage drop across the LDR. Observe the voltage voltages for Black and White tiles, choose a suitable threshold voltage say Vt. If (V

STEP 4: Simulating Touch

For this we have to understand how capacitive touch screens work. The electrodes apply a low voltage to the conductive layer creating a uniform electrostatic field. When a finger hits the screen a tiny electrical charge is transferred to the finger to complete the circuit creating a voltage drop at that point on the screen. The location of this voltage drop is recorded by the controller and this is how a capacitive touch screen works.

We are going to use this concept, except that in the place of a finger, we use the ground pin on the arduino to transfer the charge on the screen. To have more surface area on the display of the screen, we use a coin.

Relays are directly connected to the output pin of the Arduino. It is equivalent to a touch if the voltage given is high as there is a path for the current to flow to the ground. It is equivalent to not touching if the voltage given is low.

Run the test_relay code at this link to see if the electronic touch is simulated properly.

STEP 5: Finishing Touch

Once you the connect the circuit and dump the code main.ino at this link, your circuit should start working. If not, it is because the delays are not adjusted perfectly. Tweak the delay values in the code and it should work.

And you built a circuit that can play Piano Tiles better than any human in the world!!

STEP 6: Other Resources


Source codes: https://github.com/psurya1994/arduino-plays-piano-...

Blog: http://themotivatedengineer.com/blog/arduino-plays...

31 Comments

braytonlarson 8 years ago

Nice. Replace the relay with an NPN transistor though and you will have a much cheaper and smaller project.

psurya1994 8 years ago

Agreed, thanks for pointing out. :)

ssarwar 8 years ago

hy...is it possible to replace relays with npn transistors???? spent all my money buying an arduino :( relay are not so cheap

Sanderv2 8 years ago

Couldn't this also be done directly from an Arduino pin? Giving low (ground the pin) for a touch and high for no touch.

braytonlarson 8 years ago

I suppose that would work as well. Would have to add a resistor to the ground line of the arduino. Good thinking!

psurya1994 8 years ago

Nope. Never do that. You need to switch between open circuits and ground (not Vcc and ground)

satyamchauhan 1 year ago

Sir, i want to make a project.
Here, in this project there're 4 LDR are used..but in my case I have to use 12 LDR sensors.
And the colour change is from black to purple
Can you help? please.

NithinS27 5 years ago

I really want to do it, but a bit confused about connections can you (/anybody) make a full connection diagram for this project and send me .. it would be helpfull?

NikhilD59 5 years ago

Could you please explain what is the function of the relay in this circuit?

Tanmay Deuskar 7 years ago

Hello,

I've been trying to get the coin thing working, but it simply doesn't simulate the touch. Can you tell me what could possibly be going wrong or how I can troubleshoot it. I want to simulate touch using Arduino to take photos.

Thanks

SouvikC6 7 years ago

can you plz tell me how coins are used here to touch the screen??

theglenneth 7 years ago

Hey, I was wondering if you could be more detailed about how you got the screen to think it is being tapped. When i put the contact i made on the screen, it registers a tap, but when i apply 5v or 3v, it does not register as it no longer being touched. Am I hooking it up wrong?

Shivama22 7 years ago

Can u share the circuit diagram u have designed?

Aswinm1 7 years ago

Which relay did you use .I really want to make this.EAGERLY waiting for your replay.Also a very nice project

JakubZ9 8 years ago

What should be the parameters of LDR's ?

Hertafeld 8 years ago

Great project! I'm trying to do something similar using relays on a phone screen (without the arduino). I'm using tin foil contacts instead of coins due to space constraints. With one side of the relay grounded and the other making contact with the screen, activating the relay DOES register a touch. The problem I'm facing is that when the relay is switched off and the contact is floating, the phone does not register a "release" and remains "touched" until the contact is physically removed. Did you come across this issue, and how did you solve it?

asilva57 8 years ago

Great idea guy! GO ahead with the project e thanks for sharing.

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