Wednesday, February 4, 2015

Guitar Tuner using Labview and USB-6221 DAQ

            Tuning an instrument is a task that must be achieved basically every time the instrument is played. This is especially true with a guitar. Factors such as weather, temperature, the age of the strings, and even just playing the guitar causes the guitar to lose its tuning. Originally, tuning was done by the ears of musicians who would attempt to match each other’s tones, but with the rise of technology, electronic guitar tuners have greatly simplified this task. Modern guitar tuners typically clip on to the headstock of the guitar and use vibrations to determine whether or not each string is in tune. The approach of this project was to mimic this design through LabVIEW, however instead of using a clip on tuner, the signal was read directly from the input jack of an electric guitar into a data acquisition system.

Part Description
Model No. / Serial No.
Electric Guitar
PRS Custom 24 SE
Operational Amplifier
Data Acquisition System
Model USB-6221 / S.N. 1406618

I used an OP amp to increase the strength of the signal before sending it into the DAQ with a gain of 10. 

After adding a "noise gate" we got it to work very well.

Here is some output that you would see real time.

If given more time, an addition to this project would have been creating a self-tuning guitar. This could be done by attaching a servo to the tuning pegs of the guitar, and creating a feedback response system through the DAQ. If the tone was flat the servo would turn in one direction, and if it was sharp the servo would turn in the opposite direction until the desired tone was achieved.