Fun Fourier Transform Workshop: Whistle Detector
Check out this Colaboratory notebook for the exercises!
- Press "Open in Playground" under the toolbar in order to make edits.
- You will have to be signed into your Google Account to run the notebook.
If you are having technical difficulties or prefer running locally, no problem!
"File > Download .ipynb". Locally, you don't need to run the cells with following
lines of code:
from google.colab import files files.upload()
Just make sure that the WAV files are in the same directory as the notebook.
Accompanying slides can be found here!
You can request for the solutions here or by emailing me: ebezzam[at]gmail[dot]com
Requirements if running locally
Make sure you have the packages specified in
pyserial are only needed for the NeoPixels demo.
Live testing of the whistle detector
Once you have completed the following functions from the notebook:
transcribe estimateBaseFreq dtw
Copy them to the
You can then run
demo_audio_feedback.py to test the Whistle Detector!
A command line prompt will appear; you can press
"r+Enter" to record
yourself and see if you can match the "passphrase".
You should hear a bell if you whistled the correct tune and a buzzer if not.
If you have an Arduino and a NeoPixels 60 LED Ring,
you can run
demo_neopixels.py for a whistle detector that provides visual
feedback (green for correct, red for incorrect). You will first have to flash
your Arduino with
Tuning the whistle detector
Think you got it right but it's not detecting the melody? Or perhaps your detection thinks everything is correct (false positives).
You can tune the whistle detector by adjusting the following parameters:
THRESHOLDat the top of the
demo_*.pyscripts. A lower value will be more selective, while a higher value will yield a less strict detector.
Otherwise, you can tune your own whistling ;)
Workshop content is modified from material by Paolo Prandoni.
WAV file sources:
- In workshop: from Paolo Prandoni
- Bell sound: https://freesound.org/people/InspectorJ/sounds/411089/
- Buzzer sound: https://freesound.org/people/hypocore/sounds/164089/