ESP32 Bluetooth Media Controller

A customizable Bluetooth media controller based on Waveshare ESP32-S3-Zero, inspired by the Sony RM-MC25C controller design with modern enhancements.

Project Overview

This project transforms a Waveshare ESP32-S3-Zero into a powerful Bluetooth media controller with:

• Media control (play/pause, next/previous track, volume)
• Deep sleep for power saving (2-minute timeout)
• Visual feedback via RGB LEDs
• Modified RM-MC25C functionality with additional features
• Customizable button actions (including modifier key combinations)
• Smart power management using USB-C LiPo charger module

Hardware Requirements

Components

• Waveshare ESP32-S3-Zero (Main controller)
• LiPo battery (3.7V, 500mAh+ recommended)
• USB-C LiPo Charger/Booster Module (like https://www.amazon.com.mx/dp/B09YD5C9QC)
• Tactile buttons (x5)
• NeoPixel LED (optional)
• Resistors (10kΩ for pull-ups)
• JST PH 2.0 connector (for battery)

Power Setup

The USB-C LiPo Charger Module provides:

• Built-in charging circuit (no separate TP4056 needed)
• 5V boost output (powers ESP32 directly)
• On/off button functionality

Special wiring:

• ESP32 5V/GND connected to module's boosted 5V output
• DOWN button wired to charger module's power button pin
  • Single press: Turns power on/off
  • Still functions as modifier button when powered on

Wiring Diagram

Power Connections

LiPo (+) → Charger Module "BAT+" LiPo (-) → Charger Module "BAT-"

Charger Module "5V OUT" → ESP32 "5V" Charger Module "GND" → ESP32 "GND" DOWN button → Charger Module "PWR" pin

Button Connections (All using INPUT_PULLUP)

Button	GPIO	Function
DOWN	7	Modifier/Power
PLAY	9	Play/Pause
BACK	10	Previous Track/Vol-
NEXT	11	Next Track/Vol+
STOP	12	Stop/Wake-up

RGB LED Connections

• Red LED: GPIO 6
• Blue LED: GPIO 5
• Green LED: GPIO 4
• NeoPixel: GPIO 21

Troubleshooting: False Wake-Ups from Deep Sleep

If your ESP32 randomly wakes from deep sleep shortly after entering it (especially when using GPIO12 as the wake-up trigger), follow these steps to resolve electrical noise issues:

Recommended Fix Hardware Modifications (Required for GPIO12):

Add a 10kΩ pull-up resistor between GPIO12 and 3.3V.

Add a 100nF ceramic capacitor between GPIO12 and GND (for debouncing).

Circuit Diagram:

[3.3V] ----[10kΩ]----.
                     |
GPIO12 --------------+
                     |
                    [ ] STOP button (to GND)
                     |
                   [100nF]
                     |
                   [GND]

Software Configuration: In setup(), add these lines to stabilize the wake-up pin:

void setup() {
...
  pinMode(STOP, INPUT_PULLUP);  // Enable internal pull-up
  gpio_pullup_en(GPIO_NUM_12);  // Force strong pull-up
  esp_sleep_enable_ext0_wakeup(GPIO_NUM_12, LOW);  // Wake on LOW (button press)
...

Why This Happens ESP32 wake-up pins are sensitive to noise (floating voltages, EMI, or button bounce).

The 10kΩ resistor ensures a clean HIGH state, while the 100nF capacitor filters noise.

If Issues Persist Use a multimeter to verify GPIO12 voltage:

Should read ~3.3V when idle (no button press).

Should read 0V when pressed.

Shorten wires between the button and ESP32.

Replace the tactile switch (defective switches can cause floating signals).

Features

Core Functionality

• Bluetooth LE keyboard emulation
• Media control shortcuts inspired by RM-MC25C
• Enhanced with modern ESP32-S3 capabilities
• Visual status indicators

Installation

1. Hardware Setup:

   • Solder components according to wiring diagram
   • Ensure proper polarity for battery connections

2. Software Setup:

   • Install required Arduino libraries:
     • Adafruit_NeoPixel
     • BleKeyboard

3. Upload the Sketch:

   • Open WS-ESP32-Media-Controller-Sleep.ino
   • Select ESP32-S3 board
   • Upload to device

Usage

1. Power On: Press DOWN button once
2. Pairing: Connect via Bluetooth as "RM-MC25C Media Controller"
3. Controls:
   • Standard button presses for media control
   • DOWN + other buttons for secondary functions
4. Power Off: Press DOWN button twice quickly

Customization Options

• Change timeout duration in code
• Adjust LED colors
• Modify button mappings
• Create custom enclosure

Technical Specifications

Bluetooth: BLE 4.2 Operating Voltage: 3.3V (regulated from 5V boost) Current Draw: ~15mA active, ~5μA sleep Battery Life: ~20 hours (500mAh LiPo)

Features pending to add

• 3D Printed housing to put all together inside

---

License

This project is licensed under the GNU GENERAL PUBLIC LICENSE. See the LICENSE file for details.

---

Acknowledgments

This project was made possible thanks to these valuable resources:

• ESP32-BLE-Keyboard Library by T-vK
  For enabling Bluetooth HID keyboard functionality on ESP32

• Waveshare ESP32-S3-Zero Documentation
  For hardware specifications and pinout references

• USB-C LiPo Charger/Booster Module
  For providing integrated battery charging and power management

Special thanks to the open source community and all contributors whose work helped shape this project.

📬 Contact & Support

---

Project Repository:
🔗 github.com/geekinsanemx/ESP32-Bluetooth-Media-Controller

Creator:
👨‍💻 GeekInsaneMX

Need Help?

• Open an Issue on GitHub
• Share your project modifications - I'd love to see what you build!

Your feedback and contributions are always welcome! 🚀