3 1/2digit LCD interfacing with PIC or 89X051

[Ankur Kashyap]

I wanna interface the 3 1/2LCD with PIC or AT89x051 micon....i dont
have enough port pins to drive lcd..... plz suggest any multiplexing
technique.

 

[John Fields]

On 6 May 2004 02:09:14 -0700, ankurkashyap@indiatimes.com (Ankur
Kashyap) wrote:

I wanna interface the 3 1/2LCD with PIC or AT89x051 micon....i dont
have enough port pins to drive lcd..... plz suggest any multiplexing
technique.

---
http://www.national.com/ds/MM/MM5483.pdf

--
John Fields

 

[Tilmann Reh]

Ankur Kashyap schrieb:

I wanna interface the 3 1/2LCD with PIC or AT89x051 micon....i dont
have enough port pins to drive lcd..... plz suggest any multiplexing
technique.

Look at the PCF 8577, it supports 32 static segments (64 2-plex)
and has an I2C interface. Very handy device.

--
Dipl.-Ing. Tilmann Reh
Autometer GmbH Siegen - Elektronik nach Maß.
http://www.autometer.de

 

[Tilmann Reh]

Jamie schrieb:

you can use one 3 to 8 Mux type chip. this will give you 8 differenet lines
you wouldn't have to use all of the lines.
i think they also make a 2 to 4 or something line that.
those you can use to mulitplex the display.
basicly have all the segments tied together using BCD decoder(7447
type) or something that will drive the segments using only 4 lines.
other lines scan strobe the commons. THe strobes are normally driven
via some small HexFets..

[ ] You know that common 3.5 digit LCDs are static.
[ ] You know that LCDs are AC driven.
[ ] You know that LCD multiplexing is different than LED multiplexing.

--
Dipl.-Ing. Tilmann Reh
Autometer GmbH Siegen - Elektronik nach Maß.
http://www.autometer.de

 

[Jamie]

you can use one 3 to 8 Mux type chip. this will give you 8 differenet lines
you wouldn't have to use all of the lines.
i think they also make a 2 to 4 or something line that.
those you can use to mulitplex the display.
basicly have all the segments tied together using BCD decoder(7447
type) or something that will drive the segments using only 4 lines.
other lines scan strobe the commons. THe strobes are normally driven
via some small HexFets..




Ankur Kashyap wrote:

I wanna interface the 3 1/2LCD with PIC or AT89x051 micon....i dont
have enough port pins to drive lcd..... plz suggest any multiplexing
technique.

 

[Mike Page]

Ankur Kashyap wrote:

I wanna interface the 3 1/2LCD with PIC or AT89x051 micon....i dont
have enough port pins to drive lcd..... plz suggest any multiplexing
technique.

NEC uPD7225 or one of the Holtek parts

--
Mike Page BEng(Hons) MIEE www.eclectic-web.co.uk