🚀 go-pugleaf

In article <1k55dkINNe5b@digex.digex.com> bote@access.digex.com (John Boteler) writes:

>Is there a dumb UART readily available?

	Don't you really mean easy-to-use, or simple?  Why do you
CARE whether it's dumb or not?

>I am designing a box that sends out serial telemetry based on 8 switches
>being ON or OFF. A serial interface looks like a good way to do it. I
>don't need interrupts, I don't need FIFOs, I don't need modem status
>bits, I don't need none of that stuff.

>I would rather not bump the level of complexity up several notches by
>requiring a microcontroller (and its firmware) just to initialize the
>UART speed and so forth. Is there a really dumb UART that can come up in
>a known state and just shovel data?

	No.  The dumb ones don't have internal clocks, and telling them
when to send and when to shut up is slightly problematic.  The smart
ones require a CPU.

	I'd consider a Z8671 for this.  It's a Z8 microprocessor
with a dozen or so I/O lines, which powers up with two of the lines
configured for serial in/out at (I think) 2400 baud.  You send
it a command in tiny BASIC, and it reads you the input values.
Last time I looked, it's $15 or so, and needs only a crystal,
two small capacitors, and the RS-232 translation circuitry.
I think it takes 7.3728 MHz, but I'm not sure.

	There's no need to make a big project out of using
a microprocessor.  The entry level is pretty painless.

	John Whitmore