Howdy Folks,
This is my first post on this website, so please forgive me if I've put this in the wrong area.
I need a little help building an op-amp for a mini-grant project I received from my University. I'm building a simple guitar tuner that will use an Arduino Mega to detect pitch and represent each of the 12 notes as a color in the chromatic light spectrum (using a http://thingm.com/products/blinkm-maxm.html (http://thingm.com/products/blinkm-maxm.html)). The arduino will play a few random notes with PWM while flashing and then you try and play the same pattern (just like Simon).
http://www.tonychai.com/guitar.html (http://www.tonychai.com/guitar.html) <- This guy was kind enough to post his code for a guitar tuner project he built with an Arduino. I can't figure out what IC he used for his op-amp circuit... I've already modified his code to do what I need, but I can't get the arduino to read my signal.
Here's his schematic:
(http://www.tonychai.com/guitar/opamp.jpg)
I can't find an ECG891N anywhere.
I'm a Computer Science major and some of this EE stuff is over my head. I have it working using an FFT via Processing's Minim library and serial communication, but I want this to be a standalone project.
Please help!!!
Thanks,
DividedSky
I think a simple opamp will do. Something like a TL071 or something.
best of luck
RONALDB
Thanks RonaldB I'll give it a shot! I think i have to boost the voltage to 5V so the arduino can read it.
Quote from: DividedSky on August 16, 2010, 04:12:50 PM
Thanks RonaldB I'll give it a shot! I think i have to boost the voltage to 5V so the arduino can read it.
I was working on something similar and found this schematic and the website you mentioned. The boost circuit you posted is designed to increase the voltage from the guitar but I found that I needed a 0.1 uF filter on the input and output to get decent readings and a resistor to ground befor the output in order to zero the readings when the strings weren't vibrating.
Hope this helps.