Oh, I can't remember the last time I updated on this. So forgive me if
something is repetitious.
I talked my Alma Mater into having a class this spring on intro to
robotics, where they are building Mark III Mini Sumos with our
PlugaPod(TM) and our Mini Sumo Adapter board. We'd originally wanted to
use the PlugaARM(TM) for the processor. But they weren't ready. So we
shipped them half a dozen with PlugaPod(TM)s to get them going. Since
then, I've been working on this project as if it were a PlugaPod(TM)
project. (I'm trying to help write the curriculum now)
A few weeks ago, 15yo James Koffeman, who participated in its
programming effort with me, took the unit you see on the web site into
the DPRG Table Top contest, and took 1st place in Mini Sumo and 2nd
place in line following.
In the mean time, the PlugaARM became available in two forms, one the
original Pluga2129, and the other the Pluga2138. I really should go back
and review if the signals on these ARM based boards align with the Mini
Sumo Adapter board. I'm fairly sure one or both of them will, but since
the engineer who was working this job left for a position with home land
security, some of the continuity was lost, and I guess it is up to me to
go back and be sure everyting "lines up" signal wise, so you have A/D's
where you need them, and PWM where you need them, etc.
Alex, if you're interested (and there's not a conflict of interest for
you to do so), we'd trade you these boards for a check out and a sample
program for basic line following and Mini Sumo operation. Contact me by
email if you want to arrange something like that, which I think could be
a win win for both parties.
Good point! Anything that is slow and works beats anything that is fast
but doesn't work.
Yes, but that's what I'm saying, that day... _is_ today.
This just happened. The balance just tipped. (In my opinion, for sure
last week, with the new Philips price announcements to be certain.)
For example, we make a Barrel Racing Timer in our Pegasus subdivision.
We use IR remote ciruits to make a break beam. We have a little LCD on
the box, so you can read the run times right off the heads. So we used a
little 8-pin PIC iirc. Less than $2. Has 2K of code space and a very
small amount of RAM. My head of engineering did the programming on that
Anyway, with feature creep, we got to where we needed just one more
feature, to detect if we had a remote console attached. There wasn't
room in the code. Ugh. After a couple months of messing with it, he got
the feature in.
Now, today, if I were going to do the same product, do you think I'd
consider a PIC? No way. For the same money, same assembly cost, just a
different processor, I could have room for feature creep for generations
without hitting the boundaries of the LPC2131. It has 16x the memory.
And if I did feature creap out of the LPC2131, then there's the 2132,
2136, 2138 to switch to. The 2138 has 32K RAM and 512K flash. Same
footprint. The larger memory part would solder down right to the same
pads in the same product. Plus there are far more features, faster
UARTs, A/D's, I2C, CAN, etc. etc. that can be brought to my product
while staying in the same family. I could even have USB and talk to a
Further, when you talk about development: There is a build in boot
loader in the ARM that is fast! There is a JTAG port on the ARM that can
be used to debug the program. There are powerful debuggers.available as
freeware. There are fine compilers available, freeware and professional.
There are many language languages. This is a real processor that can do
subroutine calls, and run real time OS's, do interactive debugging, and
so on. Etc. Etc.
Man, why would I ever choose a PIC when I could have one of these ARMs
at the same price?
Actually, I used to favor the HC908s. Now, I wouldn't consider them
either. I'd start out assume a ARM would be the cheapest solution (in
the run sizes I normally get involved with anyway).
To get a comparable AVR (ATMEGA128) albeit still slower, I'd have to pay
~$15. (I know, we sell them too on the same size boards.) The ARMs are
way less than that.
That's what I mean when I say the day, when the ARM's are so cheap they
are used in every little project, is here today.
I don't know if a micro can be too small. I like 'em small. Particularly
now that they are rather complete systems with plenty of RAM and FLASH
inside. Mostly they just need some small amount of support extrernal.
As far as dealing with SMT... there's always some supplier that will
make a nifty little board with the chip mounted for you.
My company, New Micros, is one. We are offering the LPC2131 with 8K Ram
32K Flash, and a 60MHz 32-bit ARM7 processor all mounted with RS-232
conversion, power regulation, crystal, LED's, etc., for $29.
We've just brought out signal pins to a dual in-line .1" connector that
are easy to use on a prototype baord, or in a strip socket. So at about
half the price of a Stamp-like processor, you've got something like 20X
the computing power, in a similar foot print (narrower). Hopefully that
will make your quick and dirty prototypes even faster to whip out,
wtihout having to mess with SMT or the support circuitry.
So back to the original poster's question, I'm not sure I'd bother with
an 8-bit PIC from the past, anymore than I'd recommend you start with a
16 MHz 286 (designed about the same year) to use for your starting desk
top. Why? No modern software even runs on that processor.
By the time you're proficient with the PIC, you'll be about two decades
behind everybody else, or with a AVR, about a decade and a half. I'm
really lost on why people are so engrained in a past, that's ...
well,... past. What's up with that?
Other options like
analog devices Blackfin stamp (may be to expensive)
500MHz dsp chip
Blackfins are supposed to be based on the same instruction set as the Intel
xscale chips - jointly developed.
The blackfin chips have been popping up in quite a few bots lately.
Your can try a blackfin stamp board online free of charge
if you have a decent net connection speed and bandwidth
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