Re: gEDA-user: furnace controller II: I/O driver

["John Luciani" <jluciani@xxxxxxxxx>]

On 5/12/06, DJ Delorie <dj@xxxxxxxxxxx> wrote:
> > Have you looked at the parts from Allegro?
>
> Not until just now, but I don't see anything that would fit.  Which
> ones were you thinking of?

When I quickly read the email I saw "two wires" and  "high current IO"
and thought
MAXIM port expander (50mA output), TI power logic (TPIC) and Allegro
latches with
high current output. Most of these have many more IO ports than you are looking
for.

After looking at the schematic it looks like you are looking for (1) a
high current
output that has three states driven by a single output line that has
three states and
(2) an input pin that does not connect to the output pin. On the port
expanders the
input and output pin would be the same.

Is using the two pins to create an I2C port an option? You could get a
small port expander
(or maybe two one for input and one for output) and drive your FETs. Using I2C
would also solve your make-before-break issue.

(* jcl *)

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