of eight pins each available
on one header, and a
smattering of port pins on
dedicated connectors. It
is fairly generic in its
implementation. One really nice feature is having
three LEDs onboard for
The analog is a bit
more complicated than the GPIO, but
not by much. It is comprised of two
banks of four 12-bit A/D converters.
They are a bit persnickety in that it is
recommended they only be used in
the 0-3.0 volt range, which makes
interfacing voltage output sensors a
bit of a hassle. But that's nothing a
voltage divider and a bit of Ohm's
Law can't handle.
The communications sections
are also really quite powerful. To
start, there are two asynchronous
serial ports of which the second one
can be ordered as standard RS-232,
RS-422, or RS-485. The one drawback here is that the highest standard
baud rate is only 38400. Nonetheless,
having two hardware based serial
channels is really useful.
There is also a single SPI port
which can run at up to 20 MHz, and
can be configured as either a master
or a slave. On its connector, there are
the necessary SPI signals, and a couple of port lines, the reset line, Gnd,
+ 5, and + 3. 3 V. This makes interfacing to other devices really easy.
In addition, there is a basic implementation of CANbus on board.
While not a "full implemen-tation", it is still good
enough for most CANbus
tasks where it isn't responsible for being the master
of the bus where a high
level protocol is being
used. This really isn't an
issue, since most of us
won't be spending the
licensing fees to implement the popular CAN protocols. We will simply be
writing our own, or at worst, building
slaves that do follow a higher protocol. In any case, with error checking,
checksumming, automatic re-trans-mission, and bus conflict arbitration,
CANbus holds a lot of promise. New
Micros was even good enough to put
a CAN transceiver chip on board.
Now, before I delve into the native
language of the IsoPod, I want you to
sit back and ponder what you can do
with the IsoPod. Even if you are a
dyed-in-the-wool Intel, Atmel, PIC, or
Affordable Motion Control Products
Circle #112 on the Reader Service Card.