On Wed, 2011-03-16 at 01:38 -0700, Klemen Dovrtel wrote: > Hello everybody, > > I would like to measure some analog signals using emc (for PID > control). I think the easiest way would be to measure the pwm signal.
In case it might help, I used an SPI chip: http://www.wallacecompany.com/machine_shop/EMC2/serial_adc/ It uses parallel port bit banging, but is plenty fast enough for my use with spindle VFD DAC's. Now that I know more about comp programming, I think a much faster driver could be made. I would also consider an RS485 interface over SPI because the interference issues with machinery have been much better addressed. Or even RS232: http://www.kmitl.ac.th/~kswichit/PLogger/index.html I don't like USB but the price is right: http://www.sparkfun.com/products/9147 It may be a bit of over-kill but the Arduino and ModIO have analog inputs: http://axis.unpy.net/01198594294 http://wiki.linuxcnc.org/cgi-bin/emcinfo.pl?ModIO You may also need to consider input signal conditioning with an amplifier or voltage translation. http://zone.ni.com/devzone/cda/ph/p/id/197 -- Kirk Wallace http://www.wallacecompany.com/machine_shop/ http://www.wallacecompany.com/E45/index.html California, USA ------------------------------------------------------------------------------ Colocation vs. Managed Hosting A question and answer guide to determining the best fit for your organization - today and in the future. http://p.sf.net/sfu/internap-sfd2d _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
