I've got a low cost application where I want to drive a small LCD ( probably 4
digit ) from a microcontroller.

I looked at the data on the 'bare glass' and there are 32 pins needing driving
which doesn't leave enough for my other I/O.

Any suggestions for a cheap and cheerful controller chip ? Or is it cheaper to
get a display with integrated driver straight off ?

Graham

On Tue, 06 Feb 2007 05:51:08 +0000, the renowned Eeyore
rabbitsfriendsandrelations@hotmail.com> wrote:

I've got a low cost application where I want to drive a small LCD ( probably 4
digit ) from a microcontroller.

I looked at the data on the 'bare glass' and there are 32 pins needing driving
which doesn't leave enough for my other I/O.

Any suggestions for a cheap and cheerful controller chip ? Or is it cheaper to
get a display with integrated driver straight off ?

Graham

Does it really have to be fully static? Why not, say, a triplexed
display?

I was simply going with what I initially found.

If you have some specific ideas, I'm all ears. I'm new to driving LCDs.

Eeyore <rabbitsfriendsandrelations@hotmail.com> wrote:

I was simply going with what I initially found.

If you have some specific ideas, I'm all ears. I'm new to driving LCDs.

Microchip sells a bunch of PIC microcontrollers which are
designed specifically to drive LCDs. Ferexample, their PIC16F913
is a 28-pin part which can drive certain LCD configurations having up
to 60 addressable segments.

I believe that other micro vendors have similar parts in their stables.

You might be able to use an LCD-capable micro of this sort as your
primary programmable device... or, use one as a display-management
peripheral, talking to your main micro over a UART or other serial
interface.

Microchip sells a bunch of PIC microcontrollers which are
designed specifically to drive LCDs. Ferexample, their PIC16F913
is a 28-pin part which can drive certain LCD configurations having up
to 60 addressable segments.

Do you know how they do that ? Presumably there's an app note ?

I believe that other micro vendors have similar parts in their stables.

Ideally I'd like to stick with a member of the 8051 family for familiarity.

Microchip sells a bunch of PIC microcontrollers which are
designed specifically to drive LCDs. Ferexample, their PIC16F913
is a 28-pin part which can drive certain LCD configurations having up
to 60 addressable segments.

Do you know how they do that ? Presumably there's an app note ?

No doubt - they're quite good about providing howto-doit notes.

I would guess that the LCDs in question are generally multiplexed in a
matrixed arrangement, with some fraction being anodes and the rest
cathodes.

I believe that other micro vendors have similar parts in their stables.

Ideally I'd like to stick with a member of the 8051 family for familiarity.

Philips (now NXP) has always been big in the 8051 architecture. It
looks as if the P89LPC94x family might do what you want - it's an 8051
derivative and a "universal LCD controller" integrated into a 64-pin
multi-chip module. Toughest part may be trying to get samples, if
what I hear about NXP is true.

TI has one of the MSP430s that could be purpose made for this app too. Shame I'm
not familiar with them.

I've got a low cost application where I want to drive a small LCD ( probably 4
digit ) from a microcontroller.

I looked at the data on the 'bare glass' and there are 32 pins needing driving
which doesn't leave enough for my other I/O.

Any suggestions for a cheap and cheerful controller chip ? Or is it cheaper to
get a display with integrated driver straight off ?

I've got a low cost application where I want to drive a small LCD ( probably 4
digit ) from a microcontroller.

I looked at the data on the 'bare glass' and there are 32 pins needing driving
which doesn't leave enough for my other I/O.

Any suggestions for a cheap and cheerful controller chip ? Or is it cheaper to
get a display with integrated driver straight off ?

Graham

Spehro Pefhany wrote:

On Tue, 06 Feb 2007 05:51:08 +0000, the renowned Eeyore
rabbitsfriendsandrelations@hotmail.com> wrote:

I've got a low cost application where I want to drive a small LCD ( probably 4
digit ) from a microcontroller.

I looked at the data on the 'bare glass' and there are 32 pins needing driving
which doesn't leave enough for my other I/O.

Any suggestions for a cheap and cheerful controller chip ? Or is it cheaper to
get a display with integrated driver straight off ?

Graham

Does it really have to be fully static? Why not, say, a triplexed
display?

I was simply going with what I initially found.

If you have some specific ideas, I'm all ears. I'm new to driving LCDs.

Graham

Eeyore wrote:

TI has one of the MSP430s that could be purpose made for this app too. Shame I'm
not familiar with them.

Get familiar, free up your brain from juggling with memory spaces and
pointer snafus.

UARTs and timers are much nicer too. MSPGCC works well,

and doesn't cost a lot, and C will (may?) make porting easier (even if
you've written your app in assembler). The BIG downside is it's 3.6V max
and no 5V compliant IO.

Dave Platt wrote:
Eeyore <rabbitsfriendsandrelations@hotmail.com> wrote:

I was simply going with what I initially found.
If you have some specific ideas, I'm all ears. I'm new to driving LCDs.

Microchip sells a bunch of PIC microcontrollers which are
designed specifically to drive LCDs. Ferexample, their PIC16F913
is a 28-pin part which can drive certain LCD configurations having up
to 60 addressable segments.

Do you know how they do that ? Presumably there's an app note ?

I believe that other micro vendors have similar parts in their stables.

Ideally I'd like to stick with a member of the 8051 family for familiarity.

Do they still make the 8748? As far as I remember, it was like an

Do they still make the 8748? As far as I remember, it was like an
8035/8051 core, but with the I/O ports optimized for use as a peripheral.