This week, I used this pySerial tutorial (https://www.instructables.com/Capture-Data-From-Arduino-to-CSV-File-Using-PySeri/) to update the microphone testing code to save input data to a CSV file. These resources were helpful: https://forum.arduino.cc/t/compilation-error-read-econnreset/1114185, https://www.developer.com/languages/python/map-event-codes-python/. I also put together a test circuit (with Zeynep’s help) to confirm that the bracelet hardware can run entirely off of the battery as planned in the circuit diagram. Thank you, Freda, for suggesting these tasks!
Some of my deliverables from last week are behind schedule. However, the context and importance of some of these deliverables has changed.
Microphone signal processing is done (with Freda’s help) in the sense that microphone inputs can be obtained and used to affect other components like the LEDs. However, further improvement/debugging is needed. For example, I need to look into increasing the speed at which the Beetle runs so that microphone input can catch higher-frequency inputs such as those expected from piano or higher voices. This resource is useful for determining which frequencies correspond to notes we want to catch: https://www.omnicalculator.com/other/note-frequency.
In testing, we are not currently scaling microphone input values to correspond to decibel meter readings. It seems like the scale value varies among microphones, so the best thing to do might be to wait until we have assembled the final hardware components on the flex PCB before tuning the scale values. Similarly, the microphone testing code does not currently average samples over time. Although it is not correct for our final product to register short noises like tapping near the microphone, it is useful in testing. Also, as long as we are not weighting the input based on frequency, it is likely not necessary to perform an FFT for determining the dB value.
Visualization of decibel readings was not complete by March 30th; it is likely that this will be completed after the interim demo.
Some testing of the device has begun. It is not possible to complete the timeliness test now, because the webapp and device are not yet integrated. Similarly, since the bracelet is not assembled, passing the heat test has not happened yet. We are attempting to improve the accuracy of the microphone, but its results do not yet correspond to dB meter readings.
Deliverables for next week include placing an order for plastic wrap, helping bring the hardware subsystem (microphones and LEDs) to a testable state, and testing it in music studio sessions.