Video of Final Test

Below is a link to a YouTube video of our final testing. The seven segment and LEDs work together to display all six notes on the guitar “E4, B3, G3, D3, A2, E2”. The testing is completed in that order. The seven segment display lights up “E” for “E”, “b” for “B”, “g” for “G”, “d” for “D”, and “A” for “A”. The number of LEDs that light up correspond to the number of each note. For example, for the note “B3”, the seven segment displays a “b” and three LEDs light up.

 

Design and Construction Team Update

Testing Pictures

Above are some excel files showing our testing data for today. They were both taken from the output (in hertz) of our program, after listening to a progression of strings played on an acoustic guitar. The difference between the two is the threshold value, a value within our program that we wanted to test the difference of. The data is pretty noisy, especially towards higher notes (B and E).

Design and Construction Update

Audio Recording Test

Today we discovered the problem we were having with our circuit. The microphone audio jack was not wired to the circuit correctly. The wires were both going to the audio signal pin, so the audio jack was not grounded. To fix this, the ground wire was moved to the ground pin. Once this was done, we started seeing a proper signal on the analog input into the Arduino. This was monitored using the Waveforms software and Analog Discovery. However, the connections to the audio jack pins are loose so the wires will need to be soldered to make sure that loose connections are not causing problems.

We tested the circuit by playing the provided audio file but we believe there was interference from the phone or in the background of the audio because the frequency readings would fluctuate. Our next step is to test our circuit with a live guitar to hopefully minimize interference. Then we are going to write code to output the note being played (determined by the frequency) to a seven segment display.

Design and Construction Update

Today the Design and Construction team resumed work on the circuit and code to fix the problems from our last meeting, which were possible loose connections or problems with the potentiometer.

Our first idea was to try the circuit and code from the Arduino Guitar Tuner instructable instead to see if it worked. Unfortunately, it also did not work and we could not figure out why. We did not get any frequency output to the serial monitor. So we switched back to the original code and circuit we were using from the Frequency Detection instructable.

After rewiring the circuit and changing the code back to what we had originally, we were faced with the same issues from the last meeting. We assumed that there was a problem with the potentiometer so we switched it out for a 4.7 kohm resistor and it did not work either.

We switched the resistor out and placed the potentiometer back in and decided to use the Analog Discovery and Waveforms software to see what our input signal is. Unsurprisingly, we discovered that we were not getting an input signal. We tried switching out the microphone for an aux cord connected to the computer, but that did not work either.

We were not able to fix this problem yet, but at least we now have a better understanding of what our problem actually is. Now that we know that we are unable to get a signal from the microphone, we know what we need to work on. Once we fix this issue, the circuit should work.

Abby and Isaac met while we worked on the circuit and came up with a design for the online presentation to explain the theory behind this project.

Online Presentation Brainstorming

The Research and Documentation Team brainstormed how to best describe pitch verses frequency in a simple way such that a middle or high school student could understand. The group decided on creating an infographic using diagrams and short descriptions and drew out sample sketches on the marker board. They will also create a Instructable to describe how the project works .

The infographic will be broken into three parts: Sound Source,  Frequency (Sound Waves), Pitch (Human Ear).

Design and Construction Progress

Today the Design and Construction team met to finish building the circuit and see if the Arduino code and circuit work correctly. After building the circuit, we used code from the Arduino Frequency Detection Instructable to see if the circuit was picking up the frequency and outputting it to the serial monitor correctly.

At first, our output was reading as “inf hz” which we believe meant that there was a loose connection or the variable resistor needed to be adjusted.

After rewiring our circuit and adjusting the variable resistor, we started seeing various frequencies as our output, but when attempting to test it with the audio file, we did not have the correct output frequencies. The output would also occasionally stop, which may be the result of loose connections.

We did not get consistent, correct output frequencies, but the circuit was at least collecting data and outputting it. We will need to determine the cause of the issues and fix it. We also discussed using an oscilloscope or the Analog Discovery and Waveforms software to look at our input signal to gain a better understanding of the issues we are experiencing.