March 7 - Started devising the circuit. Order Alcohol sensors and audio jack.
March 14 - Finished first attempt at circuit. Created using 8 ohm speaker to physically hear tone difference.
March 15 - Tried to interface with phone impedance matching
April 1 - Got circuit to work with voltage regulator (9V Battery) no speaker and phone picks up signal.
April 2 - Started creating simple app to convert signal to frequency spread.
April 18 - Got phone to perform FFT and interpret signal.
April 20 - Ordered rest of components to make stand alone device.
April 29 - Finished circuit board and finalized phone app except for match BAC to know frequencies (needs more testing)
May 2 - Finished testing BAC estimated values to frequencies (hungover)
Still needed... Finish boxed product and update BAC numbers to the app.