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

A modern, robust C++ library for generating DShot signals on the ESP32 using the new ESP-IDF 5 RMT encoder API (rmt_tx.h / rmt_rx.h).
Supports all standard DShot modes (150, 300, 600, 1200) and features continuous frame transmission with configurable timing.
Now with BiDirectional DShot support and advanced command management!

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
• Advanced Command Manager: High-level API for ESC configuration and control
• Command Sequences: Predefined initialization and calibration sequences
• 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

Manual Installation

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

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⚡ Quick Start

Basic Usage (DShotRMT)

#include <DShotRMT.h>

// Create motor instance (GPIO 17, DSHOT300, non-bidirectional)
DShotRMT motor(17, DSHOT300, false);

void setup() {
    Serial.begin(115200);
    
    // Initialize the motor
    dshot_result_t result = motor.begin();
    if (result.success) {
        Serial.println("Motor initialized successfully");
    } else {
        Serial.printf("Motor init failed: %s\n", result.msg);
    }
}

void loop() {
    // Send throttle value (48-2047)
    dshot_result_t result = motor.sendThrottle(1000);
    if (!result.success) {
        Serial.printf("Throttle command failed: %s\n", result.msg);
    }
}

Bidirectional DShot (RPM Telemetry)

#include <DShotRMT.h>

// Enable bidirectional mode for telemetry
DShotRMT motor(17, DSHOT300, true);

void setup() {
    Serial.begin(115200);
    motor.begin();
}

void loop() {
    // Send throttle
    motor.sendThrottle(1000);
    
    // Get telemetry data
    dshot_telemetry_result_t telemetry = motor.getTelemetry(14); // 14 magnets
    if (telemetry.success) {
        Serial.printf("eRPM: %u, Motor RPM: %u\n", 
          telemetry.erpm, 
          telemetry.motor_rpm);
    }
}

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📚 Examples

The library includes comprehensive examples:

1. Basic DShot Control (dshot300.ino)

• Simple throttle control
• Command execution
• Serial interface for testing
• Telemetry reading (if bidirectional enabled)

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

Mode	Bitrate	Bit Time	Frame Time	Use Case
DSHOT150	150 kbit/s	6.67 µs	~107 µs	Long wires, EMI-prone
DSHOT300	300 kbit/s	3.33 µs	~53 µs	Standard (recommended)
DSHOT600	600 kbit/s	1.67 µs	~27 µs	High performance
DSHOT1200	1200 kbit/s	0.83 µs	~13 µs	Racing applications

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);

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🎯 DShot Commands

Command	Value	Description	Usage
MOTOR_STOP	0	Stop motor	Always available
BEACON1 - 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
LED0-3_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 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