by Doug Coulter » Thu Dec 16, 2010 9:12 am
Zowie, that's pretty fully featured, reminds me of some DSP's I've used, but with SOC peripherals. Probably doesn't do all that at once (common to share the SPI and I2C for example), but still more than plenty. I like USB/ethernet these days -- eliminates a lot of noise and EMP issues if done right. Or a wireless dongle on a USB port for networking.
You'll never be able to do much without some HLL -- ASM just takes too long for us humans to build up much of anything in. Hopefully you got C or something similar.
If you concentrate on tools first -- debug, opsys (copy mine for example) and suchlike, then you can do things a little at a time, and know each thing is solid before doing the next.
For example, build the 3 phase controller setup and control structure, and test that (don't even need the pump drive to do that with a scope). You let less smoke out of things that way, and lose less hair off your head. You can always add code later to say log all the info (though I tend to do that first so it's dual use -- debug, then useful later).
On any decent sized project, I spend about 80% of the total man hours in the "staring out the window" phase -- modeling in my head how threads and timing are going to be done, and interact. Then writing the actual code is very quick. As often as not, with a new thing, we'd spend some time upfront writing some basic test code (bottom up) before doing the top down, because you can't do a good job of top down unless you know what's at the bottom and any quirks it might have. Then coding is clear sailing. One of the things you normally need to find out early is how some of the "freebies" you get in the compiler work -- and are they actually useful. For example, some compilers make a ton of code for every printf, sometimes inline, and it blocks and eats so many cycles it breaks anything it's in a time-critical loop with, so you can't use a lot of what they "give you" -- it can be more of a trojan horse than a real gift, more often than not. Ditto most vendors idea of an RTOS -- many truly stink and are so wasteful of resources that I can beat a big fat chip like this with a good opsys in a much smaller and less capable pic or other dinky thing.
I don't mind a bunch of pins on a chip if they're the "outies", the Metcal eats them up and spits them out with little effort -- less than the same number of through hole pins. But BGA's and stuf like that I've never been able to do at home. I actually found that with the PCB vendor I use (or with my homemade boards) that the proto-1 service, which is plated tracks, no masks, works better there and I use a trick that makes that even better -- instead of making the lands wider than the pins (which is the norm) I make them a little smaller. This way, and solder bridges taht form are between the pins, not the traces, and wipe off easy with the iron tip. You still get self-centering. On a thick solder plate, as often as not, it's enough solder already, or real close, and I'll just use Kester 952 flux, and tap down the corners at least before even thinking about adding more solder -- sometimes it just makes a mess and wasn't needed.
Posting as just me, not as the forum owner. Everything I say is "in my opinion" and YMMV -- which should go for everyone without saying.