DShotRMT - ESP32 Library (Rewrite for ESP-IDF 5)

A simple Arduino IDE / C++ library for generating DShot signals on the ESP32 (fqbn: esp32:esp32:esp32) using the ESP-IDF 5 RMT encoder API (rmt_tx.h / rmt_rx.h).
Supports all standard DShot modes (150, 300, 600, 1200) and features signal generation and frame transmission with configurable timing.

Now with BiDirectional DShot support, advanced command management, and modern web control interface!

The legacy version (using the old rmt.h API) is still available in the oldAPI branch.

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🚀 Features

• All DShot Modes: DSHOT150, DSHOT300 (default), DSHOT600, DSHOT1200
• BiDirectional DShot: Full support for RPM telemetry feedback
• Web Control Interface: Modern responsive web UI with WiFi access point
• Advanced Command Manager: High-level API for ESC configuration and control
• Safety Features: Arming/disarming system with motor lockout protection
• Dual Control Options: Web interface and serial console control
• Real-time Telemetry: Live RPM monitoring and data display
• Hardware-Timed Signals: Independent, precise signal generation using ESP32 RMT peripheral
• Configurable Timing: Ensures ESCs can reliably detect frame boundaries
• Error Handling: Comprehensive result reporting with success/failure status
• Simple API: Easy integration into your Arduino or ESP-IDF project

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📦 Installation

Arduino IDE

1. Search "Arduino Library Manager" for "DShotRMT"

or

1. Clone this repository or download as ZIP
2. Place in your Arduino libraries folder (~/Arduino/libraries/DShotRMT/)
3. Restart Arduino IDE

PlatformIO

Add to your platformio.ini:

lib_deps = 
    https://github.com/derdoktor667/DShotRMT.git
    https://github.com/bblanchon/ArduinoJson
    https://github.com/ESP32Async/ESPAsyncWebServer
    https://github.com/ESP32Async/AsyncTCP

Manual Installation

git clone https://github.com/derdoktor667/DShotRMT.git

Dependencies

There are no dependencies for the main library. The extended example sketches are using these libraries:

Web Interface Examples (web_control.ino / web_client.ino):

lib_deps = 
    https://github.com/derdoktor667/DShotRMT
    https://github.com/bblanchon/ArduinoJson
    https://github.com/ESP32Async/ESPAsyncWebServer
    https://github.com/ESP32Async/AsyncTCP

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⚡ Quick Start

Basic Usage (DShotRMT)

// Generate "dshot300" example sketch with Arduino IDE / CLI.

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🌐 Web Control Interface

The DShotRMT library now includes a modern web interface for wireless motor control:

Features

• Responsive Design: Works on mobile phones, tablets, and desktop computers
• WiFi Access Point: Creates hotspot "DShotRMT Control" (Password: 12345678)
• Safety System: Arming/disarming switch prevents accidental motor activation
• Real-time Control: Instant throttle response via WebSocket communication
• Live Telemetry: Real-time RPM display (bidirectional mode only)
• Auto-reconnect: Automatically reconnects on connection loss

Web Interface Access

1. Connect to WiFi network: "DShotRMT Control"
2. Password: 12345678
3. Open browser and navigate to: http://10.10.10.1

Web Client Mode

1. Setup SSID and Password in web_client.ino
2. Open serial for IP
3. Open browser, http://IP

Safety Features

• Motor control is disabled by default (disarmed state)
• Toggle the ARMING SWITCH to enable motor control
• Throttle slider is locked when disarmed
• Emergency stop resets all values to safe state

Technical Implementation

• AsyncWebServer for HTTP requests
• WebSocket communication for real-time data
• JSON message format for data exchange
• WiFi SoftAP mode for standalone operation
• Automatic client cleanup prevents memory leaks

⚠️ Known Issus

Make sure you are using these libraries for ESPAsyncWebServer and AsyncTCP to use "web_control.ino" example sketch.

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📚 Examples

The library includes comprehensive examples:

1. Basic DShot Control with Web Interface (web_control.ino)

• Web Control Interface: Modern responsive web UI accessible at http://10.10.10.1
• WiFi Access Point: Creates hotspot "DShotRMT Control" for wireless control
• Safety Features: Arming/disarming system with motor safety lockout
• Real-time Data: Live RPM telemetry display (bidirectional mode)
• Dual Control: Both web interface and serial console control
• WebSocket Communication: Real-time bidirectional data exchange

Web Interface Features:

• Responsive design optimized for mobile and desktop
• Visual arming switch with safety lockout
• Smooth throttle slider with real-time feedback
• Live RPM monitoring display
• Automatic reconnection on connection loss

2. Advanced Command Management (command_manager.ino)

Interactive ESC control with full menu system:

=== DShot Command Manager Menu ===
 1 - Stop Motor
 2 - Activate Beacon 1
 3 - Set Normal Spin Direction
 4 - Set Reversed Spin Direction
 5 - Get ESC Info
 6 - Turn LED 0 ON
 7 - Turn LED 0 OFF
 0 - Emergency Stop

Advanced Commands:
 cmd <number>       - Send DShot command (0 - 47)
 throttle <value>   - Set throttle (48 - 2047)
 repeat cmd <num> count <count> - Repeat command

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🔧 Hardware Configuration

Supported DShot Modes

DSHOT	Bitrate	TH1	TH0	Bit Time (µs)	Frame Time (µs)
150	150 kbit/s	5.00	2.50	6.67	~106.72
300	300 kbit/s	2.50	1.25	3.33	~53.28
600	600 kbit/s	1.25	0.625	1.67	~26.72

For DShot, T1H length is always double T0H length.

GPIO Configuration

// Using GPIO number
DShotRMT motor(17, DSHOT300);

// Using GPIO enum
DShotRMT motor(GPIO_NUM_17, DSHOT300);

// With bidirectional support
DShotRMT motor(17, DSHOT300, true);

// Also possible, defaults (17, DSHOT300, false)
DShotRMT motor();

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🎯 DShot Commands (experimental)

Command	Value	Description	Usage
MOTOR_STOP	0	Stop motor	Always available
BEACON 1 - 5	1 - 5	Motor beeping	Motor identification
ESC_INFO	6	Request ESC info	Get ESC version/settings
SPIN_DIRECTION_1/2	7 - 8	Set spin direction	Motor configuration
3D_MODE_OFF/ON	9 - 10	3D mode control	Bidirectional flight
SAVE_SETTINGS	12	Save to EEPROM	Permanent configuration
EXTENDED_TELEMETRY_ENABLE/DISABLE	13 - 14	Telemetry control	Data transmission
SPIN_DIRECTION_NORMAL/REVERSED	20 - 21	Spin direction	Alias commands
LED 0-3_ON/OFF	22 - 29	LED control	BLHeli32 only
AUDIO_STREAM_MODE	30	Audio mode toggle	KISS ESCs
SILENT_MODE	31	Silent mode toggle	KISS ESCs

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📚 DShot Protocol Details

Packet Structure

Each DShot frame consists of 16 bits:

• 11 bits: Throttle/command value (0-2047)
• 1 bit: Telemetry request flag
• 4 bits: CRC checksum

Checksum Calculation

// Standard DShot CRC
uint16_t crc = (data ^ (data >> 4) ^ (data >> 8)) & 0x0F;

// Bidirectional DShot (inverted CRC)
uint16_t crc = (~(data ^ (data >> 4) ^ (data >> 8))) & 0x0F;

Bidirectional DShot

• Inverted Logic: High/low levels are inverted
• GCR Encoding: Telemetry uses Group Code Recording
• 21-bit Response: 1 start + 16 data + 4 CRC bits
• eRPM Data: Electrical RPM transmitted back to controller

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🛠️ ESP32 RMT Peripheral

The library utilizes the ESP32's RMT (Remote Control) peripheral for precise signal generation:

Advantages

• Hardware Timing: No CPU intervention during transmission
• Concurrent Operation: Multiple channels can run simultaneously
• DMA Support: Efficient, automatic memory-to-peripheral transfers

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📖 References & Documentation

DShot Protocol

• DSHOT – the missing Handbook
• DSHOT in the Dark
• Betaflight DShot Implementation

ESP32 Documentation

• ESP32 Technical Reference Manual
• ESP-IDF RMT Driver
• Arduino ESP32 Core

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🤝 Contributing

We welcome contributions! Please:

1. Fork the repository
2. Create a feature branch
3. Make your changes with tests
4. Submit a pull request

Development Guidelines

• Follow existing code style
• Add documentation for new features
• Include examples where appropriate
• Test with real hardware when possible

Reporting Issues

When reporting issues, please include:

• ESP32 board type and version
• Arduino/ESP-IDF version
• ESC type and firmware
• Complete error messages
• Minimal reproduction code

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📄 License

MIT License – see LICENSE

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👤 Author

Wastl Kraus

• GitHub: @derdoktor667
• Website: wir-sind-die-matrix.de