hmm hook up one of the stepper channels to a scope and see what the frequency is?
Also the code is set to full steps atm? Because if its doing microstepping the frequency has to be lower. Again depends on the driver I should look that up see if there’s a good spec sheet
Open loop stepping is working fine. (i.e. interrupts are disabled).
The vibration is happening is closed loop mode. There is no stepping happening in closed loop mode afik.
Got to be. Only thing I can think of that would be causing the vibration. Might even just be one channel oscillating. Can’t think of anything else on the motor that would cause vibration.
Course I’d be an idiot if I thought I knew everything. Just thinking trying to get probes onto stepper wires is difficult. I’ll make a extender with spots to attach probes.
It may need some hysterisis or filtering on the position sensor. The sensor could be oscillating or be just ever so slightly noisy so that it returns a stream of values which vary slightly.
In the regular servo world, I believe that this is called hunting.
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I’ve been temporarily attaching my Mechaduino to the stepper motor with rubber bands as I didn’t have long enough screws to mount them properly.
Today i realized that the boards shift quite easily because of this meaning that the reported position will not match the values obtained from the calibration routine. So the motor is constantly trying to find this location. So that was one source of error.
Also playing with the D value of the pkp pki and pkd values seems to reduce the vibration significantly. This is for the damping or overshoot.
Ultimately I am looking for a method to properly tune my motor without have to guess at all these values.
Just Came across some info on tuning PID controllers that may be of use to some.
http://robotics.stackexchange.com/questions/167/what-are-good-strategies-for-tuning-pid-loops
I now have both my Mechs running. Next step is playing around in the code and seeing what I can hook these up too. @Jarrett seems really interested in the automated Toilet Paper dispenser. 
I got some more info from Tropical Labs regarding Tuning PID and other questions. Please refer to
Determining PID values for SM-42BYG011-25 Nema17 Stepper Motor
It also appears that current sense resistors R12 and R13 which are currently 0.250 ohm resistors on our boards were changed to be 0.150 ohms but the BOM was never updated. The current Mechaduino code defines rSense as 0.150
Easiest solution is to update from const float rSense = 0.150; to const float rSense = 0.250; in file State.cpp. As stated in the above link this will reduce your maximum current to 1.3A
Are the kits in the dropbox?
We’ve commandeered one of the empty lockers for this group-build. It’s located in the left-most column, 3rd from the top. I think it has my name on it.
The kits are in there and consist of a bag of large components (the bags are named) as well as a series of four sheets of paper listing the components. Small components are taped directly to the sheets. In addition, you’ll want to print yourself the board layouts I made (see the first post in this thread). The locker also contains a bootloader programming pseudo-pogopin jig, the solder stencils, plus a very limited number of spare components.
When picking up your kit, or taking any spare components, please send me a PM to let me know.
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so… ummm…
i have 3 of the kits that I fully intend to build but will probably not get to till next year (based on my current rate of completing things)
so if anyone wants the kits they are yours for whatever i paid (think around $30 each, will have to search the thread)
How about a trade?
I swap one of my built kits for an unbuilt one?
I’d like to try a two-side solder stencil and bake.
ps A straight purchase of an assembled Mechaduino board is about $45 US or $58 CAD at todays exchange.
Mark
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I’d be interested in getting a couple more of them if they are left. The one I bought already does do what I want and it’d be nice to have a few on hand.
If I have space on a pcb run I’ll throw some more pcbs onto it.
You mind if I adjust the board some (make the components larger, slightly improved layout, etc)?
Sure, provided the schematic doesn’t change to keep the risk low. You might want to send them off yourself, might be some time before I get to them.
Yes or no on changing the 3.3V regulator to a micro switchmode one (proven on other designs I build; I hate linears)?
Otherwise I was just going to attempt making it components on one side, adding designators and making caps and resistors 0603 or 0805 as needed. Oh, and change the programming header to the same one as on STM32F4DISCOVERY boards so you can use one of those to flash bootloader.
… uh… and add 5V so it doesn’t need USB or an extra wire to function?.. errr…
@Majicj - At this point I’d rather sell the kits then trade
@LoialOtter - I have 3 of the kits available for $30 each (think that was what they cost) if you are interested. They have the wrong voltage regulator so you will need to replace it. I believe Mark got the needed replacements
Sounds like you should fork their repo and do it better 
Maybe do a small test run of yours first to minimize risk, as mentioned.
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