74HC164 to drive a LCD panel

Started by sonos November 17, 2005
Does anyone have suggestions/experience with using an 8-bit serial-in,
parallel-out shift register like the 74HC164 to drive a LCD panel? I have
been using a LCD module in 4bit mode, and want to try something a little
cheaper.

How about hints for using 2 of these in tandem for a 2 digit LCD? 3 in
tandem for 3 digit?...

It would be useful to know how to use a SPI port on a tiny AVR w/ the
shift register for driving a simple LCD display.

thanks to any an all replies
sonos scrobe on the papyrus:

> Does anyone have suggestions/experience with using an 8-bit serial-in, > parallel-out shift register like the 74HC164 to drive a LCD panel? I > have been using a LCD module in 4bit mode, and want to try something > a little cheaper. > > How about hints for using 2 of these in tandem for a 2 digit LCD? 3 in > tandem for 3 digit?... > > It would be useful to know how to use a SPI port on a tiny AVR w/ the > shift register for driving a simple LCD display. > > thanks to any an all replies
Use 74HC595 rather than '164. It is closer to SPI. -- John B
sonos wrote:
> Does anyone have suggestions/experience with using an 8-bit serial-in, > parallel-out shift register like the 74HC164 to drive a LCD panel? I have > been using a LCD module in 4bit mode, and want to try something a little > cheaper. > > How about hints for using 2 of these in tandem for a 2 digit LCD? 3 in > tandem for 3 digit?... > > It would be useful to know how to use a SPI port on a tiny AVR w/ the > shift register for driving a simple LCD display. > > thanks to any an all replies
You have to drive lcds with ac waveform, quite tricky. there are numerous driver chips around.
sonos wrote:
> Does anyone have suggestions/experience with using an 8-bit serial-in, > parallel-out shift register like the 74HC164 to drive a LCD panel? I have > been using a LCD module in 4bit mode, and want to try something a little > cheaper. > > How about hints for using 2 of these in tandem for a 2 digit LCD? 3 in > tandem for 3 digit?... > > It would be useful to know how to use a SPI port on a tiny AVR w/ the > shift register for driving a simple LCD display. > > thanks to any an all replies
The AY0438 (Microchip makes it these days) works pretty well for driving LCDs. But rolling your own is fun and if done right can be very low power. I've done the drive a shift register thing. Used CD4094, same idea as 74hc595 but cmos and works better at 3 volts. 4 of 'em will drive a 4 digit 7 segment lcd display and leave a few bits left over for colon or decimal points. The only tricky part is you need to generate an AC driving waveform in software. I just updated the shift register 60 times a second and made sure I inverted the output data every other time. At a reasonable clock speed, 60 hz is pretty simple to do with a simple timer interrupt. Mark
On Thu, 17 Nov 2005 16:20:47 -0600, sonos <sonos@nospam.thanks>
wrote:

>Does anyone have suggestions/experience with using an 8-bit serial-in, >parallel-out shift register like the 74HC164 to drive a LCD panel? I have >been using a LCD module in 4bit mode, and want to try something a little >cheaper. > >How about hints for using 2 of these in tandem for a 2 digit LCD? 3 in >tandem for 3 digit?... > >It would be useful to know how to use a SPI port on a tiny AVR w/ the >shift register for driving a simple LCD display. > >thanks to any an all replies
--- http://www.national.com/pf/MM/MM5483.html#Datasheet -- John Fields Professional Circuit Designer
On Thu, 17 Nov 2005 16:20:47 -0600, the renowned sonos
<sonos@nospam.thanks> wrote:

>Does anyone have suggestions/experience with using an 8-bit serial-in, >parallel-out shift register like the 74HC164 to drive a LCD panel? I have >been using a LCD module in 4bit mode, and want to try something a little >cheaper. > >How about hints for using 2 of these in tandem for a 2 digit LCD? 3 in >tandem for 3 digit?... > >It would be useful to know how to use a SPI port on a tiny AVR w/ the >shift register for driving a simple LCD display. > >thanks to any an all replies
Yes, you can easily drive a static LCD with daisy-chained HC595s. Be sure to write your firmware so that you keep the average DC voltage across the segements in line with the specifications (typically something like < 50mV). Multiplexed LCDs are trickier- I think you'd need a pack of resistors and I/O that can be individually tristated. Or just use a micro with an on-board controller (but that severely limits your choice of micro). Of course there are a number of driver chips available, but they tend to be a bit expensive. Best regards, Spehro Pefhany -- "it's the network..." "The Journey is the reward" speff@interlog.com Info for manufacturers: http://www.trexon.com Embedded software/hardware/analog Info for designers: http://www.speff.com
http://frank.bol.ucla.edu/AVR2LCD.htm

http://www.embeddedrelated.com/usenet/embedded/show/37931-1.php