ESP32 Polymetronome Project

Core Concept

A modular multi-track hardware metronome system capable of running multiple independent rhythm patterns synchronized to a master tempo. Built on ESP32 with OLED display and precise solenoid actuation.

Documentation

• Hardware Documentation - Circuit diagrams and component specifications
• Software Architecture - Code structure and implementation details
• Screen Layout - UI design and display management

Current Features

• Two independent metronome channels
• 20-500 BPM range with multipliers (1/4×, 1/3×, 1/2×, 1×, 2×, 3×, 4×)
• Pattern editing with up to 16 steps per channel
• Global tempo synchronization
• Real-time visual feedback
• Solenoid actuation with accent support
• Wireless sync via ESP-NOW for multiple devices

Implementation Status

1. Core Functionality

• Basic timing engine
• Pattern storage and playback
• Solenoid control
• Display rendering
• Encoder input handling
• Multi-channel synchronization

2. Enhanced Features

• Tap tempo input
• Pattern templates
• MIDI Clock sync
• Settings storage
• Wireless control

3. Hardware Improvements

• PCB design
• Case design
• Power supply optimization
• Multiple solenoid support
• LED indicators

4. Modular system:

• Connectors
• Solenoids
• Piezo buzzers
• Speakers/amplifiers
• LED arrays/strips
• LCD displays
• MIDI interface modules
• Rotary encoders
• Buttons/switches
• Potentiometers
• Accelerometers
• Wireless modules (WiFi/BLE)
• SD card readers
• External DACs
• CV/Gate outputs
• USB interfaces

Wireless Sync System

The metronome now includes a wireless synchronization system using ESP-NOW, allowing multiple devices to stay in perfect sync:

• Leader-Follower Architecture: One metronome acts as the leader, broadcasting timing and pattern information
• Low Latency: ESP-NOW provides sub-5ms latency for tight synchronization
• Robust Protocol: Custom protocol with heartbeats, tempo, pattern, and control messages
• Auto-Recovery: Followers automatically reconnect if connection is lost
• Expandable: Support for LED strips, additional solenoids, and other output devices

LED Receiver

A companion project is included for an ESP32-controlled LED strip that syncs with the metronome:

• Receives wireless sync data from the metronome
• Visualizes beats with configurable colors for each channel
• Automatically follows pattern changes
• See the LED Receiver README for details