On Sun, 2010-10-31 at 15:47 +1100, Erik Christiansen wrote: > > Also, it needs a different type of programmer. > > Ah, I'll have to look into that.
Apparently the XMega's use JTAG and PDI for programming. My programmer doesn't support either. Newer programmers should be okay and aren't that expensive, but it is something I need to consider. > > So, I'm back to looking at plain mega's. > > Sticking with plain megas is no great pain, since it's easy enough to > make your own DAC. Just add an RC low pass filter on the output of a PWM > channel, followed by an op-amp voltage follower. (OK, that's getting > close to an integrator, so one could do that instead.) > > The PWM channels can run at high rates, so it's not hard to have > reasonable responsiveness at the VFD control voltage, yet have enough RC > time constant to smooth the output. > > So, yes, you don't need an Xmega. > > Erik When I played with RC filtering PWM to get an analog signal, I used software stepping through the parport and got lousy results. So I wrote that idea off. Since then I've learned a little bit more and it seems lots of people are using it successfully. I think one needs either a higher frequency or use PDM instead. -- Kirk Wallace http://www.wallacecompany.com/machine_shop/ http://www.wallacecompany.com/E45/index.html California, USA ------------------------------------------------------------------------------ Nokia and AT&T present the 2010 Calling All Innovators-North America contest Create new apps & games for the Nokia N8 for consumers in U.S. and Canada $10 million total in prizes - $4M cash, 500 devices, nearly $6M in marketing Develop with Nokia Qt SDK, Web Runtime, or Java and Publish to Ovi Store http://p.sf.net/sfu/nokia-dev2dev _______________________________________________ Emc-users mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/emc-users
