On Sun, 3 Jun 2012, Dave wrote: > Date: Sun, 03 Jun 2012 21:08:44 -0400 > From: Dave <[email protected]> > Reply-To: "Enhanced Machine Controller (EMC)" > <[email protected]> > To: "Enhanced Machine Controller (EMC)" <[email protected]> > Subject: Re: [Emc-users] OT: and Soapbox: 3D Printer Mods? > > On 6/3/2012 8:05 PM, Charles Steinkuehler wrote: >> Generation of the step/dir signals is straight-forward, but modern >> RepRap firmware also does PID control of the extruder temperature via >> a thermister sensor. I am currently planning on using a simple 555 >> timer circuit to convert temperature (resistance) to frequency, and >> use the line-in on my motherboard (with something like Aubio) to >> detect the frequency and convert it to a HAL temperature signal that >> can be used to PWM control the heater. > > I'd be tempted to simply buy one or two PID controllers. Kelinginc.net has > them for $39 each. And those are setup so you > can use thermocouples which are cheap. > > Dave >
A single parallel port input and a V-F should work as well. Even a just OK motherboard should be able to track a 5 KHz square wave. This is good enough for ~10 Bits at a 5Hz update rate, plenty for an injector control. Peter Wallace ------------------------------------------------------------------------------ Live Security Virtual Conference Exclusive live event will cover all the ways today's security and threat landscape has changed and how IT managers can respond. Discussions will include endpoint security, mobile security and the latest in malware threats. http://www.accelacomm.com/jaw/sfrnl04242012/114/50122263/ _______________________________________________ Emc-users mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/emc-users
