A microcontroller will definitely give you better response (EMC is to slow to really scan the laser-machine tools are moving about an order of magnitude slower than a laser scan), but you would have to code the graphics or find a way to convert them. Easy enough for simple graphics like a square, but harder for something complex.
What you could do is use EMC to preprocess the image, drawing in 2D. Then capture the bitstream from the parport into the microcontroller. Each output bitstream would be a single frame, so animations will be a lot of work. On the other hand, if you are getting that involved you really should be looking at Pangolin or something like it. All you would have to do in the microcontroller then is convert the X and Y step and direction into galvo control signals. Each time you loop through the sequence it will draw the image, so it's just a matter of how fast and now frequently you run through the loop. You will probably have to run through the loop at least 20 times per second to get a flicker free image, so work backwards from there to determine how fast the processor needs to be. If the image has 10 points in it you need to be able to update 200 points per second, 100 points needs 2000 points per second. A curve needs a lot of points to look smooth. Think about how many step and direction commands EMC generates to cut a circle. Javid ----- Original Message ----- From: "Klemen Dovrtel" <[EMAIL PROTECTED]> To: "Enhanced Machine Controller (EMC)" <[email protected]> Sent: Sunday, December 02, 2007 3:36 AM Subject: Re: [Emc-users] open loop galvanometer control > > --- Jon Elson <[EMAIL PROTECTED]> wrote: > >> I don't see how EMC2 can handle this drawing task >> from G-code at >> the rates required. To draw even simple images, it >> would be the >> equivalent of running a 100 block part program 20 >> times over in >> one second (or more). Maybe you could hack up >> something with >> EMC to precompute the trajectories and then pass it >> to a >> stripped-down motion planner that gets rid of the >> interpolation >> to try to get the rate up. I'm still REAL dubious. >> You'd >> probably need to get the servo loop running at 100 >> KHz or >> something to even get close. > > So it is better to use the microcontroller then (LPC > ARM for instance). > > > > ____________________________________________________________________________________ > Be a better pen pal. > Text or chat with friends inside Yahoo! Mail. See how. > http://overview.mail.yahoo.com/ > > ------------------------------------------------------------------------- > SF.Net email is sponsored by: The Future of Linux Business White Paper > from Novell. From the desktop to the data center, Linux is going > mainstream. Let it simplify your IT future. > http://altfarm.mediaplex.com/ad/ck/8857-50307-18918-4 > _______________________________________________ > Emc-users mailing list > [email protected] > https://lists.sourceforge.net/lists/listinfo/emc-users > ------------------------------------------------------------------------- SF.Net email is sponsored by: The Future of Linux Business White Paper from Novell. From the desktop to the data center, Linux is going mainstream. Let it simplify your IT future. http://altfarm.mediaplex.com/ad/ck/8857-50307-18918-4 _______________________________________________ Emc-users mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/emc-users
