New electronics for the makerbot part 2

Here is my makerbot electronics as of Friday.


Including the relay board, there are 7 boards involved in running the bot. I finished soldering the proto board to connect my Pro Mega to the Quadstep Friday night.
I got everything torn off and installed my new board stack in place.


Still some work to do for making it look nice, but it’s already a big improvement.

Moving on to the software side, I had a heck of a time getting anything to load from the Arduino environment. After nearly 8 hours of debugging and finally loading the basic blink program via the AVR Isp port (which involved teaching the Arduino environment that my pololu AVR programmer is like an stk500v2), I discovered what was happening. It was toggling the blink Led every 2 seconds instead of 1!

I triple checked the fuse settings against various AVR calculators and they were correct. I eventually broke out the oscilloscope to look at the clock input.

(blurry shot of 8mhz signal)

(blurry, but that is 8 Mhz)
To verify, I got a picture through the microscope


That’s an 8 mhz oscillator all right. The only problem is that Sparkfun doesn’t sell a 5V 8 mhz version of this board. They’ll be getting a call tomorrow.

With that knowledge and some munging, I got a 8 mhz bootloader going, and then tried to load marlin reprap firmware. Turns out marlin requires 16 or 20 Mhz.
Next was Sprinter, which I could get loaded, but I wasn’t able to get any functions working.  I took a brief detour to write a small sketch for letting me manually toggle all the I/O functions and some rudimentary jogging functions. A few minor edits to the board and I was left to wonder about firmware again.

A bit more digging brought me to Teacup, which is designed to still work even on an Atmega 168 which is pretty impressive. I spent some time tweaking it, and I can now control my makerbot again.

After that I spent some time with Slic3r and pronterface and have a nearly functional system!

imageUpdate: I brought my board into work to take a shot with my TDS544A since it’s a faster scope and screenshots work:

TDS544A 2013-07-15 075155

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