Marlin HAL

Hardware Abstraction Layer

A Hardware Abstraction Layer allows applications to discover and use the hardware of the host system through a simple, portable and abstract API, regardless of the type of the underlying hardware. (Pennington H., 2003)

Marlin 1.0 was originally derived from Sprinter and GRBL which could only run on 8-bit AVR boards. With the proliferation of new boards based on a variety of processor architectures, for Marlin 2.0 we decided to keep the existing code, but add architecture-specific HALs (AVR, SAM, STM, ESP) as a bridge between Marlin’s high-level code and the low-level functions that control the microcontroller’s pins, ports, timers, etc.

This way all the existing high-level Marlin code can work on any platform without needing to be concerned about the details. Retaining AVR compatibility and a single codebase is important to us, because we want to make sure that features and patches get as much testing and attention as possible, and that all platforms always benefit from the latest improvements.

Current Marlin HALs

AVR (8-bit)

board	processor	speed	flash	sram	logic	fpu
Arduino AVR	ATmega, ATTiny, etc.	16-20MHz	64-256k	2-16k	5V	no

DUE

boards	processor	speed	flash	sram	logic	fpu
Arduino Due, RAMPS-FD, etc.	SAM3X8E ARM-Cortex M3	84MHz	512k	64+32k	3.3V	no

ESP32

board	processor	speed	flash	sram	logic	fpu
ESP32	Tensilica Xtensa LX6	240MHz	—	—	3.3V	—

LPC1768 / LPC1769

boards	processor	speed	flash	sram	logic	fpu
Re-ARM	LPC1768 ARM-Cortex M3	100MHz	512k	32+16+16k	3.3-5V	no
MKS SBASE	LPC1768 ARM-Cortex M3	100MHz	512k	32+16+16k	3.3-5V	no
Selena Compact	LPC1768 ARM-Cortex M3	100MHz	512k	32+16+16k	3.3-5V	no
Azteeg X5 GT	LPC1769 ARM-Cortex M3	120MHz	512k	32+16+16k	3.3-5V	no
Smoothieboard	LPC1769 ARM-Cortex M3	120MHz	512k	64k	3.3-5V	no

SAMD51

boards	processor	speed	flash	sram	logic	fpu
Adafruit Grand Central M4	SAMD51P20A ARM-Cortex M4	120MHz	1M	256k	3.3V	yes

STM32F1

boards	processor	speed	flash	sram	logic	fpu
Arduino STM32	STM32F1 ARM-Cortex M3	72MHz	256-512k	48-64k	3.3V	no
Geetech GTM32	STM32F1 ARM-Cortex M3	72MHz	256-512k	48-64k	3.3V	no

STM32F4

boards	processor	speed	flash	sram	logic	fpu
STEVAL-3DP001V1	STM32F401VE Arm-Cortex M4	84MHz	512k	64+32k	3.3-5V	yes

Teensy++ 2.0

boards	processor	speed	flash	sram	logic	fpu
Teensy++ 2.0	AT90USB1286	16MHz	128k	8k	5V	no

Teensy 3.1 / 3.2

boards	processor	speed	flash	sram	logic	fpu
Teensy 3.2	MK20DX256VLH7 ARM-Cortex M4	72MHz	256k	32k	3.3V-5V	yes

Teensy 3.5 / 3.6

boards	processor	speed	flash	sram	logic	fpu
Teensy 3.5	MK64FX512VMD12 ARM-Cortex M4	120MHz	512k	192k	3.3-5V	yes
Teensy 3.6	MK66FX1M0VMD18 ARM-Cortex M4	180MHz	1M	256k	3.3V	yes