Photo Update

Pictures of our final circuit


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.

Design and Construction Team Update

Circuit DesingToday we met up with our parts to begin working on the construction of the circuit. We were able to set it up except for the 9 V batteries because we don’t have those yet. We also will have to solder wires to the potentiometer to connect it to the breadboard and connect the microphone input to our circuit. Our design is based on an Arduino Audio Input instructable. Our code will be based on an Arduino Frequency Detection instructable. Both of these links will be posted below. We are also working on a Fritzing diagram for our circuit. We plan on having a working project by April 21st.

The circuit diagram is from



Parts Order

Radio Shack

  • PC-Mount Condenser Microphone Element (2)
  • 1/8-Inch Mono Inline Audio Jack 2-Pack (2)
  • 1/4-Inch Mono In-Line Audio Jack 2-Pack (2)
  • Heavy-Duty 9V Snap Connectors (2)
  • Input Amp (2)
  • Uni-Directional Dynamic Microphone (1)


  • J-FET Amplifier 2 Circuit (5)
    • Part Number: 296-1780-5-ND
  • Analog Microphone Electret Condenser Omnidirectional (3)
    • Part Number: 102-1722-ND
  • 10k Ohm Gang Linear Panel Mount Potentiometer (3)
    • Part Number: 987-1301-ND
  • 100k Ohm ±5% 0.25W Through Hole Resistor (10)
    • Part Number: CF14JT100KCT-ND
  • 10µF 16V Aluminum Capacitor (10)
    • Part Number: P5134-ND
  • 0.047µF -20%, +80% 25V Ceramic Capacitor (10)
    • Part Number: P4307-ND