It seems like the MSP430 voltage levels are not working with LCD voltage levels.
Therefore I get partial strings displayed on the LCD.
In the code I'm trying to write 'hello' on the LCD. After
comparing characters appearing on the screen vs the CHAR ROM of the controller
it seems that the lower nibble doesn't get to the LCD completely. Upper
nibble is fine.
At this point I would conclude that the voltage levels of MSP430 are not fully
compatible with the 5V LCD (and vice versa).
Any other experiences?
Regards,
Chetan Bhargava
--- In m..., "cbhargava" wrote: >
> I have a few 3M breadboards and a couple from Jameco.
> Jameco is 20 minus away from where I work :-)
>
> --- In m..., Dan Bloomquist wrote:
> >
> > cbhargava wrote:
> > > Launchpad with i2c port expander PCF8574
> > >
> > > http://www.flickr.com/photos/cbhargava/5512862128/
> > >
> >
> > If you want to experiment I highly recommend you get prototype boards
> > from Jemco, they are the best quality in my experience. And a handful of
> > telephone cable. That wire they sell for those boards is worthless. I
> > have some ~100 pair chunks of cable I pull wire from. It just makes life
> > fun.
> >
> >
> >
> > Best, Dan.
>
I have a few 3M breadboards and a couple from Jameco.
Jameco is 20 minus away from where I work :-)
--- In m..., Dan Bloomquist wrote: >
> cbhargava wrote:
> > Launchpad with i2c port expander PCF8574
> >
> > http://www.flickr.com/photos/cbhargava/5512862128/
> >
>
> If you want to experiment I highly recommend you get prototype boards
> from Jemco, they are the best quality in my experience. And a handful of
> telephone cable. That wire they sell for those boards is worthless. I
> have some ~100 pair chunks of cable I pull wire from. It just makes life
> fun.
>
> Best, Dan.
>
If you want to experiment I highly recommend you get prototype boards
from Jemco, they are the best quality in my experience. And a handful of
telephone cable. That wire they sell for those boards is worthless. I
have some ~100 pair chunks of cable I pull wire from. It just makes life
fun.
--- In m..., Dan Bloomquist wrote: > The next time I do a display I most certainly plan to
go the I2C way.
> (then the extra pins are there if you need them, doesn't matter!) Yet I
> haven't checked if the timing on 'read' will clear the pcf8574
spec, it
> is a 'strange' device. I've only used it to read a switch
setting so
> far; but for writes it should be easy.
>
> Best, Dan.
>
Reply by cbhargava●March 9, 20112011-03-09
I fixed the data port, RS and EN lines. I had it jumbled up before.
--- In m..., Dan Bloomquist wrote: >
> Before I go for the night, one thing I noticed is you have the data buss
> on P.0 to P.3 where I write the code for P.4 to P.7. Change the code or
> change the pin assignments.
>
> Best, Dan.
>
Before I go for the night, one thing I noticed is you have the data buss
on P.0 to P.3 where I write the code for P.4 to P.7. Change the code or
change the pin assignments.
Best, Dan.
Reply by cbhargava●March 9, 20112011-03-09
As a matter of fact my next step would be to use i2c expander or a 5 cent shift
register. Jameco has a shift register for 5 cent.
I have the IO expander currently built on a small RadioShack PCB with two LEDs.
The board is connected to the launchpad running the i2c master demo firmware
from TI.
Maybe I'll post a picture.
--- In m..., Dan Bloomquist wrote: >
> cbhargava wrote:
> > This is more clear rendering in browser.
> >
> > https://github.com/microwiz/msp430-lcd4bit/raw/master/main.c
> >
>
> Very nice work. Please keep posted on how it pans out in the real world.
> The next time I do a display I most certainly plan to go the I2C way.
> (then the extra pins are there if you need them, doesn't matter!) Yet I
> haven't checked if the timing on 'read' will clear the pcf8574
spec, it
> is a 'strange' device. I've only used it to read a switch
setting so
> far; but for writes it should be easy.
>
> Best, Dan.
>
Very nice work. Please keep posted on how it pans out in the real world.
The next time I do a display I most certainly plan to go the I2C way.
(then the extra pins are there if you need them, doesn't matter!) Yet I
haven't checked if the timing on 'read' will clear the pcf8574
spec, it
is a 'strange' device. I've only used it to read a switch setting
so
far; but for writes it should be easy.
