grbl_stm32f4

Purpose

This a port of the grbl 0.8c g-code interpreter to the STM32F4 SoC

The STM32F4 SoC has attractive features for a realtime G-Code interpreter and machine controller.

• Lot's of IO - it's possible to run more stepper motors, more limit switches, etc.
• A Floating Point Unit - good for doing the linear/circular interpolation math.
• Fast (168MHz 32-bit versus 16MHz 8-bit for the atmega328p).

Target Platform

STM32F4Discovery Board

• http://www.st.com/web/catalog/tools/FM116/SC959/SS1532/PF252419
• http://www.digikey.com/short/504hf

Build tools:

GCC Toolchain

• https://launchpad.net/gcc-arm-embedded
• [gcc-arm-none-eabi-4_9-2015q2] (https://launchpad.net/gcc-arm-embedded/4.9/4.9-2015-q2-update/+download/gcc-arm-none-eabi-4_9-2015q2-20150609-linux.tar.bz2)

STLink Programming Tool

• https://github.com/texane/stlink

Target CNC Machine

This code is a straight port of grbl and is adaptable to many stepper drivers and CNC machines.

My test and development has used:

Gecko Drives G540 4-Axis Digital Step Drive

• http://www.geckodrive.com/geckodrive-step-motor-drives/g540.html

KRMx01 CNC Router

• http://www.kronosrobotics.com/krmx01/

Additions

• Support for XYZY axes operation has been added. ie- Two stepper motors, controlled in the same way, are used to drive the Y-axis.
• All input signals (homing switches, e-stop, etc.) are debounced in software.

Status

• Non-volatile EEPROM storage of configuration parameters is not currently supported. The EEPROM facility is being faked with RAM based storage. The desired machine parameters should be compiled into the firmware.
• The CDC USB serial device implemented on the board is not as reliable as it needs to be. Pending bug fixes the option of a normal serial port using the USART hardware has been implemented. This can be enabled in the makefile by setting "USB_SERIAL = 0".