Cello Analyzer

Project Summary

A Photon 2–based system for cello performance and instrument care.

The Cello Analyzer combines a PDM microphone, DHT20 environmental sensor, SparkFun MicroOLED, RGB LED, buzzer, Particle Cloud, Initial State, Blynk, and a PySide6 desktop dashboard to monitor live playing dynamics and safe storage conditions in one device.

Live waveform visualization
Dynamic labels from pp to ff
Temperature and humidity tracking
Cloud, mobile, and desktop views

Sizzle Reel

Performance

Estimates sound level from PDM audio, maps it to musical dynamics, and draws the waveform on the OLED.

Environment

Tracks temperature and humidity to determine whether the cello is in a safe, cautionary, or problematic environment.

Feedback

Uses an RGB LED, buzzer, OLED pages, Initial State, Blynk, and a desktop dashboard for live feedback and logging.

Build

Hardware and Setup

Component	Pin	Purpose
PDM Microphone	`A0`	Microphone clock signal
PDM Microphone	`A1`	Microphone data input
RGB LED Red	`D2`	Red channel for visual feedback
RGB LED Green	`D3`	Green channel for visual feedback
RGB LED Blue	`D4`	Blue channel for visual feedback
Piezo Buzzer	`A5`	Audio feedback for dynamic transitions
Enable Switch	`D6`	Turns the system on or off
Pushbutton	`D7`	Cycles through OLED pages
MicroOLED Display	`I2C`	Displays waveform, dynamics, and environment data
DHT20 Sensor	`I2C`	Measures temperature and humidity
LiPo Battery	`JST battery connector`	Portable power supply

Wiring Diagram

Display System

OLED Pages

Performance: live waveform, current dynamic, and current volume percentage
Dynamic Trend: percentage of time spent in pp, p, mp, mf, f, and ff
Current Environment: current temperature and humidity
Environment History: temperature high/low and humidity high/low

The waveform is drawn on the first page by drawPerformanceScreen() in src/celloanalyzer.cpp.

Connectivity

Cloud, Initial State, and Blynk

Initial State Event

The project publishes the event Cello_Analyzer every 2500 ms using millis()-based timers.

[
  {"key":"volume","value":42},
  {"key":"temperature","value":23.2},
  {"key":"humidity","value":55.4},
  {"key":"dynamic","value":"pp"}
]

Cloud Variables

mode

dynamic

volume

raw

temp

hum

alert

celloHealth

Initial State Tile	Type	Purpose
Humidity	Gauge Tile	Displays current humidity with a visible safe-range region
Temperature	Gauge Tile	Displays current temperature in Celsius using a thermometer-style visualization
Volume	Line Graph Tile	Displays historical trend of volume percentage over time
Current Dynamic	Summary Tile	Displays the current dynamic label such as `pp`, `mp`, or `f`
Most Frequent Dynamic	Summary Tile	Displays the most commonly occurring dynamic over recorded history
Humidity	Line Graph Tile	Displays historical humidity trend over time
Temperature	Line Graph Tile	Displays historical temperature trend over time

Initial State Demo

Cello Analyzer Initial State dashboard demo

Blynk Display

Blynk Datastream	Virtual Pin	Data Type	Purpose
Switch Mode	`V0`	Integer	Virtual page-change button
Current Mode	`V1`	String	Displays current OLED mode
Dynamic	`V2`	String	Displays current musical dynamic
Current Volume	`V3`	Integer	Displays current volume percentage
Current Temperature	`V4`	String	Displays current temperature
Current Humidity	`V5`	String	Displays current humidity
Current Health	`V6`	String	Displays cello health message
Current Environment	`V7`	String	Displays environment status
Dynamic History	`V8`	String	Displays recent dynamic history summary
Temp History	`V9`	String	Displays temperature high/low summary
Humidity History	`V10`	String	Displays humidity high/low summary

PySide6 App

Desktop Dashboard

A PySide6 desktop version of the project is included in the repository and mirrors the embedded system with live waveform visualization, environmental monitoring, and an OLED-style preview panel.

Live waveform visualization
Current volume and dynamic display
Temperature and humidity monitoring
Mock data mode for UI testing
Serial data source scaffolding for Photon 2 integration
Session recording and CSV export

Desktop Dashboard Preview

Portfolio Video

A Photon 2–based system for cello performance and instrument care.

Hardware and Setup

OLED Pages

Cloud, Initial State, and Blynk

Desktop Dashboard

Project Demo