Single Button Page Turner (SBPT)

A BLE keyboard controller for M5Stack AtomS3 that enables wireless page turning on Kobo e-readers.

Author

Morten Teinum (morten.teinum@gmail.com)

Hardware

• Device: M5Stack AtomS3
• MCU: ESP32-S3 FN8
• Dimensions: 24.0 x 24.0 x 12.9mm
• Weight: 6.9g
• Connection: Bluetooth Low Energy (BLE)

Features

• Short Press: Next page (Right Arrow key)
• Long Press (≥600ms): Previous page (Left Arrow key)
• Visual Status Indicator:
  • Green filled square: BLE connected
  • Red outline square: BLE disconnected

Setup

Method 1: Pre-compiled Firmware (Easiest)

Download the latest firmware from Releases

Using esptool (Command Line)

pip install esptool

# Flash all three binary files
esptool.py --chip esp32s3 --port /dev/ttyUSB0 --baud 921600 write_flash -z \
  0x0 single-button-page-turner.ino.bootloader.bin \
  0x8000 single-button-page-turner.ino.partitions.bin \
  0x10000 single-button-page-turner.ino.bin

Note: Replace /dev/ttyUSB0 with your port:

• Linux: /dev/ttyUSB0 or /dev/ttyACM0
• macOS: /dev/cu.usbserial-* or /dev/cu.wchusbserial*
• Windows: COM3, COM4, etc.

Using ESP Flash Download Tool (Windows)

1. Download Espressif Flash Download Tool
2. Select ESP32-S3
3. Load the binary files:
   • 0x0 → single-button-page-turner.ino.bootloader.bin
   • 0x8000 → single-button-page-turner.ino.partitions.bin
   • 0x10000 → single-button-page-turner.ino.bin
4. Select your COM port and click "Start"

Method 2: Build from Source

Prerequisites

1. Install Arduino IDE or Arduino CLI
2. Install ESP32 board support
3. Install required libraries:
   • M5Unified
   • ESP32 BLE Keyboard

ESP32 BLE Keyboard Library Modifications

The project requires a modified version of the ESP32 BLE Keyboard library (v0.3.0) to enhance BLE security and compatibility with Kobo e-readers.

Applying the Patch

A patch file is provided in patches/BleKeyboard.patch. After installing the ESP32 BLE Keyboard library:

cd ~/Arduino/libraries/ESP32-BLE-Keyboard
patch -p1 < /path/to/single-button-page-turner/patches/BleKeyboard.patch

View complete patch content

The patch file is located at patches/BleKeyboard.patch in this repository. It contains all necessary modifications to make the ESP32 BLE Keyboard library compatible with Kobo e-readers.

Upload Instructions

2. Upload the sketch to your M5Stack AtomS3

3. Pair with your Kobo e-reader:

   • Device name: Kobo PageTurner
   • Look for it in Bluetooth settings on your Kobo

Usage

Once paired, simply press the button on the AtomS3:

• Quick tap: Turn to next page
• Press and hold: Go back to previous page

The display shows the current connection status and button functions.

Configuration

You can modify these settings in the code:

• BLE_DEVICE_NAME: Change the Bluetooth device name
• LONG_PRESS_MS: Adjust the long press threshold (default: 600ms)

License

MIT License - see LICENSE file for details.