[sdiy] Multiple LCD connection sanity check please

[Neil Johnson]

Hi Tom,

> I'm ok with that. Following advice I received here in the past, I've written a buffered LCD output routine. You can stuff long messages into a buffer, and then a background task sends a character to the LCD every 0.5mS. The only clever bit is that you can also send delays to the LCD buffer, which makes it easy to deal with LCD commands that take more than a single 0.5mS time period.

Well, if you have lots of displays then you'll presumably have lots of
data to display on them?  In which case 2000 bytes/s may not be fast
enough.  In principle you can send characters to the LCD drivers in
sub 100us.  Some commands take longer (RETURN is typically >1ms).

> Failing that (simply paralleling them all up) I guess I'd be looking at adding a tristate buffer between the LCD inputs and the bus, would I?

You could probably get away without using tristate buffers, unless
these were hanging off a system data bus.  I don't think that's the
case here though.

> Well, 6 or 8 would be nice. Shall I give it a whirl and let everyone know how I get on?!

I guess it all boils down to your specific application, so yes do try
it and let us know!

(BTW, little nitpic: capital-S stands for Siemens, the unit of
conductance; seconds is small-s).

Cheers,
Neil
-- 
http://www.njohnson.co.uk