Ultrasonic Keyboard

Hi, I just had an idea, i would like to create something like this:

I would like to do it with an ultrasonic sensor, but it doesn't arrived yet to home so I don't know how it works. I know that it can measure the distance, but i saw few projects that use it like a radar, so can it give me x, y e z of an object? In this case I will interface it with a bluetooth module and at the coordinates of a key it will send the letter via bluetooth. Do you think that is possible?

Thanks for the answer :slight_smile:

gdandrea97:
Do you think that is possible?

No.

Ultrasonic sensor have detection about 3 degrees, at this short distance, that will not able to identify the key.

And with two ultrasonic sensor? One on the front and one on the side, to measure the distance for the x and the y axis? Or it isn't enough accurate?

gdandrea97:
And with two ultrasonic sensor? One on the front and one on the side, to measure the distance for the x and the y axis? Or it isn't enough accurate?

There are many reasons why this will not work. Besides other things, how will your system know when a key is actually pressed?

It's best to wait until you have an ultrasonic sensor, then see what it's capable of, don't you think?

so can it give me x, y e z of an object

I understand x, y and z. What is e?

gdandrea97:
And with two ultrasonic sensor? One on the front and one on the side, to measure the distance for the x and the y axis? Or it isn't enough accurate?

The thing about ultrasonics is with simple devices like these, it's hard to perform two measurements simultaneously, and because of the need to allow distant echoes to die away, your update rate is very limited - I usually allow no more than 20 measurements per second, so with two devices, each device would be limited to 10 measurements per second.

And, as has already been pointed out, how do you distinguish a key-press vs. a finger merely hovering?