Regarding Firmware, you might want to have a look into Teacup_Firmware. Teacup is all plain C, compiles without Arduino libraries and has a plentitude of configuration options already. And it's compatible with official FiveD, of course. Traumflug 10:39, 5 March 2011 (UTC)
Thanks Traumflug, I'll check it out. I probably won't start working on the next version of Repic until Microchip come out with a 40-pin DIP PIC24F chip, but when they do that sounds like it'll be perfect for getting the firmware to run off USB memstick. Myndale 10:30, 7 March 2011 (UTC)
No sign of the 40 pin PIC24F yet. They do have a 44 pin quad that could be mounted on a carrier but this will be extra work. While browsing their site it occured to me that it might be possible and in some way perhaps easier to integrate the controller into 2 20 pin PICs. One could be dedicated to the motion control stuff and the other could be the interface and accessories that do not require speed. This would remove all the interrupts and code for PID loops, USB and other stuff from the stepper processor. The one device could just run the vectors (maybe that is what the 5D part is about) and the other one could do the house keeping. The loss of an SPI port for the inter IC communications shoud still leave enough pins to get most of the jobs done with care. I am trying to get my RepStap ready for electronics and will consider this platform for testing. I hear that the project is still active but no sharing has been done due to lack of interest. Some of this due to broken contact forms and such on his personal web site (contact me if you need his email address) but we are bound to have an update one day. KalleP 11:20, 22 January 2012 (UTC)
Full speed ahead
I love the idea of a through hole budget set of electronics, I'm also a PIC fan. I also love any ideas on reducing the cost of US$12/14 stepper boards with just a US$2/3 IC on them. The retail pricing is appropriate but there should be some way to get a hobby friendly pricing as well.
The other cheap mass produceable board (Melzi) has all the parts on the board and it adds in a option for a cooling fan that some people use, it could be for the extruder, heatsinks, cabinet heater or some other output, I believe one transistor to drive an optional feature will allow for quite a bit of experimentation. Also any spare pins still need to come out on a header to allow max flexibility.
A one wire serial LCD interface would be nice, it seems the 'g-codes' support debug and status messages, I suppose someone has done this already.
I also look forward to the free C compiler version that can integrate the G-code interpreter in the PIC.
Having a USB memory stick interface makes it more universal, memory cards come in so many flavours but USB is only one. Do you plan to allow both USB host and slave connected together or just one at a time?
Perhaps it is time soon to come up with a standard way to store the basic configuration parameters in a .INI file or something, not sure if this is the case yet but from reading is still seems that the numbers are standardised but they are not stored in any common form. A default set as RepRap.INI and one with the same filename as the G-codes like MotorMount1.INI for special parameters, possibly offering relative adjustments in % as well as absolute figures if you know which machine it will be printed on. KalleP 07:57, 5 January 2012 (UTC)