Grbl_ESP32 CNC Development Board

This is development board for using CNC on Grbl ESP32. It supports all of the current and planned features of Grbl_ESP32. It is a great way to get started with the firmware.  It is currently for sale in my Tindie shop.

ESP32 brings the following benefits Grbl

  • Small and very low cost
  • Powerful dual core processor running at 240MHz per core
  • 4MB of flash RAM
  • Floating point coprocessor
  • On board Wifi
  • On Board Bluetooth


  • A very modular design – If any of the major circuits get damaged, you can plug in a new one.
  • A socket for a ESP32 Dev board also known as NodeMCU 32S. Most 19 pin per side dev boards should work, just check the pins or ask me.
  • (3) Sockets for stepper motor drivers. These fit many types of drivers. The TI DRV8825 type is my favorite driver for this type of application. Micro-step selection jumpers are included.
  • Home/Limit switch connections for XY and Z axes. These also have R/C filters to eliminate high frequency noise from false triggering the switches.
  • Z Probe connections with R/C filter
  • Control switch input connections for Feed Hold, Cycle Start, Reset and Door. These have filters as well as pullup resistors, because they are on inputs that do not have internal pullups.
  • Spindle output for PWM (Speed). Spindle Enable and Direction are also connected, but not in firmware yet.
  • A socket for a micro SD card module. Note: The SD card feature is in testing and not in the master branch firmware yet. Also it shares pins with other non-popular features that would have to be turned off (Mist Coolant, Spindle Direction and Spindle Enable)
  • DC-DC power supply. There is a strong 3A DC-DC power supply to run the ESP32 if it is not connected to USB. It is adjustable, 0.8V to 20V, but would typically be set to 5V. It also has connections, for off board use.

Required Modules

What it Comes With

  • Fully soldered based board.
  • DC-DC P/S installed and adjusted
  • Basic Testing and Inspection (Voltages  and components)

Open Source

The design is open source with Creative Commons 4.0 Attribution – Share Alike . Here are the source files.


  • The SD Card pin 5 (vcc) was accidentally hooked up to 3.3V. It should be connected to 5V. The boards have a simple cut and jump. Keep this in mind if you use the gerber files.

Where to get one

You can build your own from the source files or you can buy one from my Tindie store. Buying one from me helps support this project.

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3 Responses to “Grbl_ESP32 CNC Development Board”

  1. Colin

    I like this poduct a lot and repect your work but $19.00 shipping costs to Europe is prohibitive. Can you not exlore more competitive shiping arrangements?

  2. Frederir

    Do you think you would support an I2C IO extender in future version ? The goal would be to add a 4th axis and to allow more I/O for HMI.

    Slow outputs like Mist, Flood, Enable should not be affected with the increased latency of I2C. It may be possible to have dedicated SPI for the SDCard also.

    What do you think ?

  3. bdring

    That is likely to happen in the future. Initially, I am focused on completing all features with on chip resources.