Alright, this is going to be a lot of info, but I've had a difficult time finding out where to start with due+ramps-fd. I found the Due for cheap from banggood (http://www.banggood.com/Arduino-Compatible-DUE-R3-32-Bit-ARM-With-USB-Cable-p-906466.html, $20) and RAMPS-FD from Geeetech (http://www.geeetech.com/new-pololu-shield-rampsfd-for-arduino-due-3d-printer-controller-p-770.html, $28). Almost cheaper than MEGA+RAMPS! I also like the RADDS shield (http://max3dshop.org/index.php/default/elektronik/radds/radds-v1-1.html)that has very similar functionality, it's just more expensive (>2x).
More info about RAMPS-FD is available here (http://reprap.org/wiki/RAMPS-FD) including a schematic that can help decipher the unlabeled pins of the board itself. Geetech has its own wiki with duplicate info (http://www.geeetech.com/wiki/index.php/Ramps-FD, not sure who copied who) but neither have very helpful diagrams. I've made my own here (http://imgur.com/CnByrtf) with room for improvement. I'll add it to the reprap wiki soon. This is RAMPS-FD v1 (from what I understand v2 is final and v3 is on the way). It is important to note that v1 has reversed (logic?) on the mosfets, so if the arduino power fails, the heaters turn on. This is an important fix in v2, but I'm working with v1 for now.
The marlin port is discussed at length here (https://github.com/ErikZalm/Marlin/issues/626) including its practicality since a total rewrite could have many advantages. Bobc has the port of marlin I'm using, found here (https://github.com/bobc/Marlin) although supposedly repetier and a couple others have firmware that works with RAMPS-FD (and usually RADDS). There are three main forum posts I've found (including this one) that talk about projects with RAMPS-FD (http://forums.reprap.org/read.php?1,291043,291043 [forums.reprap.org] [andy-projects.blogspot.com]) They've all either had issues or just not been active enough put all the necessary info together to get it to work (thus this post).
I've also had issues with firmware similar to the issue found here (https://github.com/kliment/Printrun/issues/484) that I've solved by Unistalling the arduino Due usb driver (that I believe installs by default, but I'm left with "USB Serial (Communication Class, Abstract Control Model) (COMX)" You also MUST connect at 115200 baud rate and or else you get a communication error, and you must use the programming usb port, not the native port, to connect.
This is all I have for now, but it's connecting to just the Due on it's own in pronterface! I'll hook up the RAMPS-FD tomorrow morning and post an update
More info about RAMPS-FD is available here (http://reprap.org/wiki/RAMPS-FD) including a schematic that can help decipher the unlabeled pins of the board itself. Geetech has its own wiki with duplicate info (http://www.geeetech.com/wiki/index.php/Ramps-FD, not sure who copied who) but neither have very helpful diagrams. I've made my own here (http://imgur.com/CnByrtf) with room for improvement. I'll add it to the reprap wiki soon. This is RAMPS-FD v1 (from what I understand v2 is final and v3 is on the way). It is important to note that v1 has reversed (logic?) on the mosfets, so if the arduino power fails, the heaters turn on. This is an important fix in v2, but I'm working with v1 for now.
The marlin port is discussed at length here (https://github.com/ErikZalm/Marlin/issues/626) including its practicality since a total rewrite could have many advantages. Bobc has the port of marlin I'm using, found here (https://github.com/bobc/Marlin) although supposedly repetier and a couple others have firmware that works with RAMPS-FD (and usually RADDS). There are three main forum posts I've found (including this one) that talk about projects with RAMPS-FD (http://forums.reprap.org/read.php?1,291043,291043 [forums.reprap.org] [andy-projects.blogspot.com]) They've all either had issues or just not been active enough put all the necessary info together to get it to work (thus this post).
I've also had issues with firmware similar to the issue found here (https://github.com/kliment/Printrun/issues/484) that I've solved by Unistalling the arduino Due usb driver (that I believe installs by default, but I'm left with "USB Serial (Communication Class, Abstract Control Model) (COMX)" You also MUST connect at 115200 baud rate and or else you get a communication error, and you must use the programming usb port, not the native port, to connect.
This is all I have for now, but it's connecting to just the Due on it's own in pronterface! I'll hook up the RAMPS-FD tomorrow morning and post an update