So I'm wondering (and I realize it might me far fetched) if it is possible to open a guitar tuner, and somehow connect it's circuit to arduino and make arduino read the values being sent to the LCD display on the tuner?
A variation of this might be reading the data being inputed into the tuner, instead of reading the data outputed to the LCD itself. I really want to make a different kind of guitar tuner, but for my project I need really good frequency detection so I don't think that if I made one myself (including coding the freq. detect.) it would be accurate enough.
In theory you can do it, but in practice it is a lot of a pain. This is because LCD signals are complex multi level signals and they take a lot of fishing out.
Of course you can tap into any digital line, and unless it's got some undocumented encryption you can decode it. But if your intent is to 'make a different kind of guitar tuner' then you learn nothing about that and gain nothing other than learning how to decode an LCD.
A tuner has 3 aspects, input, process, output. It -can- be done in 1 chip, so there's no 'reading the data being inputed into the tuner, instead of reading the data outputed to the LCD.' At least, that's the cheapest way to do it. Regardless, if there's a separate analog input interface chip, and even another driver to the LCD, there's no other point where you can tap into 'data.'
You'll learn a lot more and make more -direct- progress towards a tuner by researching and studying waveform analysis. There's got to be a ton of info available about it ranging from algorithms-101 tutorials to whole books. Start with the -101.
'I need really good frequency detection so I don't think that if I made one myself (including coding the freq. detect.) it would be accurate enough.'
You're not going to get that by decoding a $20 tuner either. A consumer grade item is designed/calibrated by referencing against lab grade tools. There are also lots of hobby grade versions too that can get you off the ground. The 'accurate enough' is in the ADC resolution bits. That's it. After that the software is researchable. Check sourceforge.net. I'd half-bet there's an open source project or even several projects going on there. Check github too. Now those are more likely about PC based tools not Arduino, but they'll point your researches in the required directions.
My point is that LCD driving lines are not digital logic, but mulit level signals.
Also there are several different types of LCD, as explained.
You're not going to get that by decoding a $20 tuner either
Wouldn't be so sure, don't forget that you pay for software once only, with hardware you pay every time.
Detecting a note can be difficult because of the harmonic content, notice that tuners do not always give the octave but just the note. It is a mistake to think that the fundamental is always the largest harmonic or the lowest harmonic.
Grumpy_Mike:
You're not going to get that by decoding a $20 tuner either
Wouldn't be so sure, don't forget that you pay for software once only, with hardware you pay every time.
Detecting a note can be difficult because of the harmonic content, notice that tuners do not always give the octave but just the note. It is a mistake to think that the fundamental is always the largest harmonic or the lowest harmonic.
Yes, but to what purpose, and by what means? The tuner accepts analog-in. That can be controlled by a generator(s). Then inside the chip is 'mystery software' (the software that the OP wants to 'do better' than.) Then LCD-out. The only possible way to perform the exercise is to know, down to the nth detail, exactly what's going into it tuner, and then watch how it displays. With that, yes, one could figure out at least what 'kind' of analysis it's doing to find frequency/octave/whatever. However, the only way to do that kind of analysis, again with nothing more than audio input, with the high-end hardware, and an LCD output is to already -know- how to do what the chip is doing in the way of audio analysis. A class-A (just for reference) engineer -could- do that kind of analysis on any device, because he already knows every algorithm. By the behavior of the output as compared to the input he'd 'know' what the software was doing. But for an 'I have an Arduino' newbie, it's simply purely absolutely impossible to learn anything, other than how to decode LCD signals.
By analogy, it's like putting a car on jacks, starting the car and putting it in gear, watching the wheels spin around, and trying to 'analyze' the fuel injection and ignition systems, to build a better motor that improves mileage.
Don't get me wrong! I'm NOT saying that OP CAN'T build a better trapper-of-mice, only that 'decoding an LCD' is the -completely- wrong way to go about it.
The OP asked about reading an LCD display.
He did not aske about building a better tuner, he gave the tuner as an example of what he might want to do with the technique. He was not very specific about what these improvements were to be so I think you are some what jumping the gun here.
First off thank you guys for the answers I really appreciate it.
My main problem is with hardware however, as I don't have access to a radioshack for example, and getting parts takes a lot of time, so all I have a couple of cheap piezo's which I have tried many times to use but that simply arn't good enough to detect the vibrations on a guitar with enough precision for me to be able to use that as an input device to then calculate the note. I am a fairly good programmer and I think I could make a frequency detection algorithm (I said I didn't want to in order to make my explanation simpler) but I simply don't have the hardware to do it.
As for what the tuner looks like inside, I can indentify the piezo with one connection on the outter ring and one on the inner one just as it should be, and the screen has 3 wires attached to it, red green and black. Ive attached the pictures of the tunner so u guys can see too
