When you use Due as the controller of your 3D Printer, you may find the RAMPS1.4 is not compatible with DUE.As you know the Due is a microcontroller board based on the SAM3X8E Cortex-M3, the importance is the SAM3X8E chip used on the Due operates at 3.3V,worse applying 5V to the Due's inputs will likely damage the chip. So we create a new RAMPS variant which is compatible with the Due to replace Ramps1.4. Why should I use Ramps-FD instead of Ramps1.4 Campare Ramps-FD with Ramps1.4,the Improvements of Ramps-FD are below * The RAMPS-FD has other hardware protection, through the jumper cap control motor drive IC * The RAMPS-FD Much more than Ramps1.4 2-way PWM * The RAMPS-FD has Larger driving power than Ramps1.4 * The RAMPS-FD 'POWER has two choices:12v and 24v * CPU operates at 3.3V * High-current IO pins are capable of 15 mA source, 9 mA sink * Low-current IO pins capable of 3 mA source, 6 mA sink * CPU package has an absolute max of 130mA * The Due has 1 dedicated SPI port, and 4 multipurpose USART/SPI ports. The SPI port is only routed to the 6 pin header used for ICSP on Mega, but this is not used for ICSP on Due * The Due does not have any EEPROM * Due has lower power, computing faster and flash, sram bigger than mega2560