Rabbit GRBL

GRBL-compatible motion control firmware for ESP32

Deterministic, high-speed and stable motion control firmware, designed for real CNC machines and long production jobs, with predictable behavior, precise timing and reliable multi-axis control, engineered for continuous operation, low latency, accuracy, robustness, scalability, safety.

Introduction

Rabbit GRBL is a Motion control firmware for ESP32.

This repository is maintained to provide a professional-grade, fast and predictable firmware that remains
100% backward compatible with the original Grbl v1.1h for AVR processors command set and works with all standard GRBL G-code senders.

Rabbit GRBL is optimized for stable timing and low jitter, achieving up to 120 kHz step pulse rates on ESP32 hardware, making it suitable for real CNC machines — not experimental setups.

Design Goals

• Deterministic motion control
• Stable behavior under continuous load
• Full GRBL compatibility (no surprises)
• Predictable execution for production use

Features

• Control of up to 6 axes
• Step rates up to 120,000 steps/sec
• Jitter-free pulse generation
• Backlash compensation
• Canned Cycles G73, G81, G83
• User-defined homing sequences
• WiFi, Bluetooth & USB / Serial connectivity
• Optimized for ESP32 dual-core architecture

Compatible Hardware & Software

Rabbit GRBL runs on ESP32-based CNC controller boards and remains fully compatible with the standard GRBL ecosystem.

You can use it with supported ESP32 hardware as described in the official hardware compatibility list:

👉 Compatible Hardware
https://github.com/SourceRabbit/RabbitGRBL/wiki/Compatible-Hardware

On the software side, Rabbit GRBL works with all standard GRBL G-code senders, without requiring proprietary tools.
You can find the full list of compatible software here:

👉 Compatible Software/G-Code Senders
https://github.com/SourceRabbit/RabbitGRBL/wiki/Compatible-GCode-Senders

Because Rabbit GRBL is 100% backward compatible with the original GRBL (AVR) command set, it integrates seamlessly with existing GRBL-based workflows.

Build & Usage

Build instructions, configuration options and usage examples are documented in the Wiki:

👉 https://github.com/SourceRabbit/Rabbit_GRBL/wiki

Community & Support

• Discord community
  https://discord.gg/nRKETyjJ7E

• Official website
  https://www.sourcerabbit.com