Same here. I have some AVR code that may do what you want. I don't know what it will take to convert it to arduino. It's part of the controller for my rotary table. There's a link to the source at the bottom.
http://www.franksworkshop.com.au/Workshop/RotaryTable/RotaryTable.htm The code is based on the algorithm posted on the yahoo "geckodrive" group. Look in "Files" | "G100 and G101". There are algorithms for linear (MOVEAXIS.gif ) and S curve (ramp in S out.gif ) acceleration. Disclamer: It's some of the worst code I've written, but it mostly works (changing on the fly is buggy) > -----Original Message----- > From: Bernhard Kubicek [mailto:[email protected]] > Sent: Thursday, 15 April 2010 6:21 AM > To: Enhanced Machine Controller (EMC) > Subject: Re: [Emc-users] OT Arduino program question. > > I don't do Arduino, I do ATMEGAs with GCC. > Anyway, I would try to create a timer interrupt. Before > starting the timer, it is possible to set a starting value > for the counters. In the interrupt vector routine, one could > set each time a new increasing/decreasing starting value, to > create ramps. > Or, alternatively, one could do something like this: > uint16_t max=100,min=0,c; > for (c=min;c<max;c++) > { > _delay_us(c); > set_your_softPWMpins(); > } > At least AVR-GCC. > With arduino and java(?) i have less clue.. > greetings, > bernhard > > > On 4/14/2010 9:49 PM, Greg Bentzinger wrote: > > Hello List; > > > > I have a simple machine that needs a single axis control to > rotate a crank shaft 220 degrees then back. I plan to use a > NEMA 34 stepper and a Gecko for the motion. I will mount > large XL pulleys on the crank and use about a 5:1 reduction ratio. > > > > Limit at one end of the stroke home at the other. > > > > I want to use an Arduino to run the thing, but I have not > found much info in the area of programing accell curves for > the step/dir outputs. > > > > I need to program ramp to max, move xxx steps, ramp down to > a very slow speed for the last 30 degrees, stop and dwell > then ramp to max back to home and stop. > > > > I have been searching the Arduino forms and most examples > are for users actually trying to control the phase outputs of > drives they have built on "shields". Also these users believe > in "Instant acceleration" they just start a pulse stream with > no ramp up. Floppy drive steppers turning tape flags can > kinda get away with that, but I'm driving a load on a Nema 34 > and I don't want to pound the crap out of the works. > > > > My plan goes like this: > > > > Digital Inputs: > > > > a} Home switch > > b} Limit switch > > c} Jog forward > > d} Jog reverse > > e} Start > > f} menu ? > > > > Digital Outputs > > > > a} Direction > > b} step > > > > Analog Input - Potentiometer as feed override 0-100% > > > > Estop will be all hardware so its not an issue. > > > > I ask here because I know a few users have been toying with > the Arduino for use as a cheap micro PLC to work with EMC2. > > > > I'm just looking for a few lines of code that show how to > insert accell / decell ramps into the sketch. > > > > I will end up mounting a degree wheel on the crankshaft and > adding or subtracting steps as required for best use. > > > > Right now it is all done by hand with a lever. I expect > running by hand is faster - but slow and steady wins the race > and operator ( that would be me) fatigue is always a factor > in actual production output. > > > > > > And because Enquiring minds will want to know... The > application is a 1964 model (San Diego) Star Lube sizer. :) > With all the extra bells and whistles (almost), Base heater, > Lube pressure system and bullet feeder. > > > > Maybe later I can build a mini Puma robot to sort them. > > > > Thanks all. > > > > > > > ---------------------------------------------------------------------- > > -------- Download Intel® Parallel Studio Eval Try the new > > software tools for yourself. Speed compiling, find bugs > proactively, > > and fine-tune applications for parallel performance. > > See why Intel Parallel Studio got high marks during beta. > > http://p.sf.net/sfu/intel-sw-dev > > _______________________________________________ > > Emc-users mailing list > > [email protected] > > https://lists.sourceforge.net/lists/listinfo/emc-users > > > > > -------------------------------------------------------------- > ---------------- > Download Intel® Parallel Studio Eval Try the new > software tools for yourself. Speed compiling, find bugs > proactively, and fine-tune applications for parallel performance. > See why Intel Parallel Studio got high marks during beta. > http://p.sf.net/sfu/intel-sw-dev > _______________________________________________ > Emc-users mailing list > [email protected] > https://lists.sourceforge.net/lists/listinfo/emc-users > ------------------------------------------------------------------------------ Download Intel® Parallel Studio Eval Try the new software tools for yourself. Speed compiling, find bugs proactively, and fine-tune applications for parallel performance. See why Intel Parallel Studio got high marks during beta. http://p.sf.net/sfu/intel-sw-dev _______________________________________________ Emc-users mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/emc-users
