AVR-Chat

I've looked at the higher pin count parts some but there are a couple of
problems with them. This will be just a hand wired on perf board circuit to
test and those higher pin count chips tend to be in the newer high density
packaging. I have found a few sockets that seem to be for doing that which
will likly end up using at some point anyway. The other is, Im not sure the
ADCs will be fast enough to do what I want even with one chip per coil. It's
not that the cpu won't be fast enough, but I'm not sure I'd get the sampling
rate I need. The goal is to try and monitor when the coil becomes saterated
by monitoring the voltage drop across it and then cutting the power and
allowing a FWBR capture the back EMF. The turn the coil on again repeatin
until the rotor has passed a certain point at which time the coil would be
left off until time to fire again. each coil cpu would get 2 rotor signals,
one for polarity passing magenets and when they are in line and the other a
pulse train to provide postion between pole shifts. the cpu would provide 2
signals used for controling the coil. The master control cpu would then
decide how many coils need to be used at the time.

The first test motor will only have 6 magnets and 5 coil pairs. But latter
versions will have more rings of coils and magnets with each ring increasing
number of magents and coil pairs by 4. It would get to be a lot of cpus, so
moer centralized would be prefered. I may be able to do compairs against set
voltages insted, since I'm mainly looking for the voltage to reach a certain
high or low. I haven't seen any min compair speed yet lookin over the pdfs,
but havn't had time to look much for that.


----- Original Message ----- 
From: "Zack Widup" <w9sz@prairienet.org>
To: <AVR-Chat@yahoogroups.com>
Sent: Monday, March 13, 2006 8:37 AM
Subject: Re: [AVR-Chat] selection for coil control


> If you're going to do that, why not just go with one chip with more pins?
> Or do the individual controllers have to be in different locations?
>
> Zack