Re: Wico XY Pattern Generator - Schematic capture complete

On 11/14/2011 9:58 PM, Clay Cowgill wrote:
> I went to the TI Stellaris training a while back (got the little robot
> thing they gave away), but I haven't done any real designs with it.
> The built in MAC/PHY combo is cool though. Finding something that
> lashed up to the parallel PHY signals on the OMAP was a PITA.
And the PHY you find will cost you more than the CPU!
> I got burned on the ATXMega128A1 that supposedly supported x8 SDRAM.
> Except for the little detail in that it doesn't. Then the one that
> is going to have that capability has been on "next quarter" status for
> about a year and a half. ;-) OTOH, I do like their really small parts
> (Tiny13A, Tiny24A, Mega48, etc.) and kinda sprinkle them around on
> things probably more than I should.
I still use them for anything small (they definitely have easier to use
EEPROM and I like the instruction set). I had planned on using external
SRAM with the ATXMega256A1, wonder how will that would have worked out.
> I had a real unpleasant experience with the i.MX31 (we tried to answer
> "which operating system do you want to use-- Windows CE or Linux?"
> with "none of the above" and had a six-month detour trying to get the
> right information to use the 3D accelerator), then I had to *not* use
> the official PMIC because it wasn't available in a ball pitch that we
> could manufacture affordably so I had to DIY a power controller... and
> that was not much fun to make work right. FYI, if the clocks come up
> before the right power rail sequence on an i.MX31, you're calling
> 1-800-NEW-CPU. :-( And the DDR controller was finicky. Not much fun
> at all.
> To their credit, Freescale fixed a bunch now with the i.MX53 and that
> design actually mostly fired up first try (again some PMIC weirdness,
> but nothing fatal).
Freescale scares me, I've heard too many horror stories from engineering
friends about using Freescale ARM's.
> > The ZVG uses Atmel parts. Obviously a firmware update could turn the
> ZVG into a
> > real nice pattern generator, but if I were to redesign it, I would
> definitely go ARM.
> > They're just so damned easy to use, and with that kind of power,
> throw in an emulator
> > and you have a CCPU on chip! It'd probably end up being cheaper as
> well, or at
> > least very similarly priced.
> Yup. I'll say that I have a STM32F103RFT6 on a design with a vector
> generator right now. ;-) A half dozen years back we did an emulated
> vector system that used a raster display and didn't see the light of
> day, so we're bolting that on to a 'real' vector generator now
> instead. We still need to write a CCPU core, but we already have our
> 6502 and Z80 cores in ARM assembly which covers most of the rest of
> the vector titles we're interested in.
Cool!
>
> > For your design, you could probably have run the vector generator
> almost completely
> > in the background, using the DMA controller and timers, and in the
> foreground run an
> > FFT on the ADC inputs and based your patterns on frequency, beat, as
> well as amplitude.
> > Same part count, similar cost.
> I really just used the XMega because we have one on our ArcadeSD
> board, so it was easy to hack the op-amps on and drive the laser from
> that without needing to do a new PCB. (We were having a chiptune
> concert at the arcade the next day and I wanted to bring something for
> visualizations, so it had to be zero-leadtime hack on something else.
> ;-) I must say though that the XMega's event system can really do a
> lot of interesting stuff too-- again, virtually a complete VG without
> any CPU-- but as soon as you start dealing with anything >8 bits the
> ARM really starts to shine, and certainly for emulation there's no
> contest.
I was looking forward to playing with the event system in the XMega, it
looked pretty damned cool, but like I said, they never built the part.
> I still think it'd be fun to do a little Asteroids 'dongle' that just
> plugs in to the ILDA connector on a laser and plays the game directly
> without needing lasermame or a USB DAC or any of that stuff. Probably
> of very limited interest, but 'neat' counts for something. :-) At
> least with lasers you really only need to give it 'endpoints' and as
> the mirrors slew you get your 'line' as a result. But there's a bit
> of black-magic associated with getting the endpoints right that I
> never bothered to figure out. It worked "good enough" for what it was
> needed for and I left it alone after that...
'Neat' counts for a lot! ;-)

-Zonn

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Received on Tue Nov 15 05:57:10 2011