Hello. So today I got my very first Arduino, and after burning one LED, I managed to figure out how to properly connect them, read resistance on resistors, read and write serial IO etc... Well, basically, what I'm trying to say is that I'm very new to this circuitry and hardware type of engineering, and that my experience is limited to few years of physics classes that I had in my school.
My project is somewhat demanding for a newcomer, as I'm trying to determine which keys are pressed on a synth and send them via serial port on Arduino. As of now, I've, with much ease, figured out the latter part, but the former one still stumbles me.
I'm unable to figure out where to start... I was attempting to measure voltage on my multimeter to determine which wire releases/drops current when any keys are pressed and I was unable to find anything (and honestly I was afraid of srewing up, since it was hooked up to an outlet, and I'm not sure will it do anything to me, even if it transforms from 220 V to 5 V).
My plead goes to any good soul willing to help me with this, as I'll gladly post pictures of the circuitry so I can ease you in the progress. Any help will do, even if someone knows any good video/tutorial on something similar that will help me solve my issue..
Thanks. (Sorry if it makes little sense, I'm not a native English speaker and it is too late, so I'm not very focused on proofreading).
If your musical instrument has a MIDI output, then the problem is already solved. If it doesn't, then go buy one that does. They're not expensive. A second-hand store probably has a few for around the price of a new Arduino.
Well, that's the problem. I live in a country that doesn't have that kind of stores, and if it has them, there would be little chance of finding one that has MIDI output, and even if I found it, it would be a intended for professionals and cost thousands of dollars (something I cannot afford). And mine, of course, doesn't have MIDI output on it.
Does eBay not work in your country? Is there no local equivalent? You will be surprised how cheap a MIDI keyboard can be. If it's got no actual synthesizer in it, or a very poor one, then it is not expensive to produce.
Send us some photos of the circuit board just under the keys. See if you can identify the switch element that senses the motion of the key. Give us a closeup of just 2 or 3 keys. Both sides of the board, if possible.
MorganS:
Does eBay not work in your country? Is there no local equivalent? You will be surprised how cheap a MIDI keyboard can be. If it's got no actual synthesizer in it, or a very poor one, then it is not expensive to produce.
Send us some photos of the circuit board just under the keys. See if you can identify the switch element that senses the motion of the key. Give us a closeup of just 2 or 3 keys. Both sides of the board, if possible.
It kinda works, but the shipping and import charges usually add up to be almost same price as the product, so it isn't worth it.
Thanks for your willingness to assist me. I'm going to post some pictures of the circuit board the first chance I get...
I have also found out that those resistors on the bottom give a 0.2 (± 0.01) V voltage in idle state, and when a key they correspond to is down, they drop to 0.14 (± 0.01) V.
Is there any way to connect them all to Arduino (maybe via analog input), and somehow receiving the states of all the keys?
What is your goal? What do you want to see when you press a key?
You are correct this is a big first project for a newcomer, but you will always be a newcomer if you have to be told what to do for everything.
Keep sticking your meter on random things if that's how you want to explore, but it would help if you had some understanding of how the keyboard works from power in to signal out.
I have started attempting the design for this in Circuits.IO. (https://circuits.io/circuits/2504225-synth-interpreter-arduino). But my Arduino only has 8 analog input ports, and I have only 10 NPN transistors... For my idea (to make a digital output pin switch active transistors every n miliseconds, so I can get states of all keys) that won't be enough.. Is there any smarter idea that utilizes 10 or less transistors.
Available components (that I currently have): 50 resistors (10 kOhm and 330 Ohm), 10 diodes, 10 LEDs, 10 transistors, also some potentiometers and photoresistors...
Those are diodes. They look like diodes and their names printed on the board all start with "D".
Can you get to the other side of the board with the keys?
That ribbon cable between the two halves looks like a good target. It might just have one wire per key. Does it? Then plugging the Arduino into that won't be hard at all.
