I got the parts in from digikey today, and assembled a couple of the rStep boards. Seems that sanguino uses the 644p and I ordered the 644. Additionally, I’m clocking the 644 at 20Mhz while the sanguino expects 16Mhz. I had to make a number of changes to make the 644 work with the arduino. First, I had to modify the bootloader by adding an entry for the 644 @ 20Mhz, recompiled it, and uploaded it through the JTAG port. Additionally, the boards.txt file had to be changed to reflect the 644 @ 20Mhz. Now, it is compatible with the arduino IDE and I was able to compile a simple LED blinking application and upload it without problems. A few more tests and I’ll be able to send out the beta boards to the developers for further testing.
After a failed order (and 2+ months of waiting) for a PCB order from dorkbot, I reordered the PCB through seeedstuio. $40 shipped for 10 PCBs was great, but they ended up shipping me 18 (must have had extra space on the panels). I paid an extra $10 for the white soldermask (I’m so sick of green. I never want to see a gree PCB). A few weeks later, I got them.
For those of you who have stopped following my CNC posts, I’ve still be active working on an open-source project called rStep. Yes, the r is for Reza. I’m egotistical that way. Anyhow, it’s been a really interesting experience and I’ve gained a lot of insight in running an open-source group. Last I checked, there were 78 members subscribed to the mailing list, and we have about 1/2 dozen active participants who are submitting code, testing, etc. I love seeing an idea start to become something real with people who are interested in the same stuff as I am and see the advantages to such a system. Check out the rStep page for more information.
The parts order is in place, this will be the final beta version (v3) and v4 will be a production run.
I was showing a friend my progress with the code, and he was complaining that the stepper motors were loud, and suggested I turn on fractional stepping. I switched to 1/16th steps, and he was right, the motors sounded much better. Additionally, the Z-axis magically started working! I was also impressed how well my code handled high stepping rates — well, more surprised that it worked without more surprises. So I’ve passed a big hurdle. I need to test the circle routine (pretty much the only piece of code I’ve not rewritten from the original code base), do some more tests, and try milling my first PCB!
Here’s a quick video demonstrating it moving in 3 axis at different rates, 1/16th step.