Thursday, August 21, 2008

Controller board, v2

The second version of the controller board for cncFDM is complete. I already have a list of fixes that are required for version 3, but I limped this one along. (Yes, you can guess, the first version didn't go so well ).

I use one-sided boards so i can mill and drill them in one shot on the mill. Here's the eagle file:


And the resulting populated and connected board:


The firmware is written in C using a demo version of mikroC ( ) Quite a nice compiler.

I almost ran out of memory on the PIC18F4331, bit after some extensive optimization i finally fit it all in.

More on the firmware later


Erik de Bruijn said...

Wow, I like it that you're using the more powerful PIC microprocessors (like I do of tommelise). The PIC electronics for the RepRap PIC electronics were very low-end PICs, so a switch to Arduino was a big upgrade, but the difference with PIC18Fnnnn is not so big at all and PICs are cheap and ubiquitous.

I love it that you made single side PCBs. I hope the RepRap will do PCB milling soon. There's someone with great results on a slightly adapted Darwin.

Then again, Sanguino is even heavier than most PIC18's. So mainstream RepRaps are also on a good path without many restrictions.


(see also my RepRap 3D printer blog)

Dave said...

Hi, Erik, thanks!
Yep, i looked at Arduino quite hard, and follow those projects-- they are quite nice.

In the end I "picked" pics because the 18F4331 has an onboard some _very_ nice peripherals.

In particular, I was interested in the quadrature encoder ("motion feedback module") , hardware PWM, and hardware SPI. They make a project like this very easy relatively speaking.

That's the lazy programmer in me talking, anyway ....

Forrest Higgs said...

I've just switched over to Mikroelektronika's Basic compiler. Their compiler family seems to be pretty solid from what I can see so far. I'm a little curious why they charge so much for for their C compiler, though.

Dave said...

Yeah, I dunno, guess they figure they can.

Its a shame that MicroChip's compilers are so crappy. I cannot even run MPLAB on my computer without it crashing. I really like PICs but their software is so bad it really makes me want to switch.

I live with PICs because (1) they tend to have better peripherals, and (2) my main hobby is micro r/c aircraft, and small pics are tiny enough to do circuits that fly :)