Help: New advice for Graphics LCD

[Brian Kidney]

Hi,

I am looking to start a project using a monochrome LCD with touch
capibiliies. I am wondering what sort of microcontroller I will need.
Will be able to get away with using a PIC or will I need something
with a little more power? Anyone have any idea what sort of program
space I will need? There will be no animation and mostly graphic
buttons and text.

Thanks,
Brian

 

[PeteS]

I assume you are using a STN type LCD module with a touch screen
interface. You'll need a 4-wire touch controller (assuming you are
using a 4-wire system). it's possible to make your own, but existing
parts to do this are common (Philips UCB14000 for instance).

LCD video controllers implement huge amounts of logic to control the
pixel drawing. you might get away with a PIC if you were using dual
ported RAM - otherwise you might well need something more beefy.

A lot depends on exactly what style (resolution, type etc) of LCD
display you are using.

Cheers

PeteS

 

[Joerg]

Hello Brian,

The versions I dealt with (mostly Optrex) typically had their own
processor board for the LCD and an encoder for the touch screen. This
meant two serial connections and not much to do for the system uC. The
fact that is was two serial connections did present a wee problem though
and we sometimes needed a mux for that.

Regards, Joerg

 

[Wouter van Ooijen]

LCD video controllers implement huge amounts of logic to control the

pixel drawing. you might get away with a PIC if you were using dual
ported RAM - otherwise you might well need something more beefy.

A lot depends on exactly what style (resolution, type etc) of LCD
display you are using.

A lot also depends on what you mean by 'PIC' - a 6-pin 0.5k code 10F
chip, or a 30F with lots of memory?


Wouter van Ooijen

-- ------------------------------------
http://www.voti.nl
Webshop for PICs and other electronics
http://www.voti.nl/hvu
Teacher electronics and informatics

 

[Marco Genise]

[email protected] (Brian Kidney) wrote in

Hi,

I am looking to start a project using a monochrome LCD with touch
capibiliies. I am wondering what sort of microcontroller I will need.
Will be able to get away with using a PIC or will I need something
with a little more power? Anyone have any idea what sort of program
space I will need? There will be no animation and mostly graphic
buttons and text.

Thanks,
Brian

Hi Brian,

I'm currently working on an control-interface for an 640x480 stn color
lcd. As I didn't have any knowledge on driving such lcds before, I had to
learn a lot.
Depending on the size of your lcd microcontrollers like pic or atmega
will be to "small". It starts with the ammount of ram they provide. Just
calculate the memory needed to represent one frame on your display. The
other side is the timing for driving the lcd. It might be possible to do
with fast microcontrollers, but not even easy.
There are some controller-chips out there which are able to interface
lcds directly. I currently work on an EPSON S1D13A04, which does the
whole driving/interfacing timing of the lcd. It has buildin RAM and some
graphics-functions. Just have a look at the datasheet for details. On the
other side it has some kind of "universal" host-controller interface,
which you are able to connect to a wide range of microcontrollers/cpus.
My project for example is based on a Freescale/Motorola ColdFire.

Using a touchscreen is another story. There are touchscreens with mainly
three different interfaces out there: 4-wire, 5-wire and 8-wire. Second
they differ in technology, which will also require a different
controller. Most touchscreen are resistive.
There also exist a lot of controller chips or even ready controller
boards which can be interfaced to RS232 or USB for example. National
provides such controller chips with LM8300/LM8500. As I know 3M
manufactures controllers boards. There are also a few other manucatureres
of those chips/board.
If you have some knowledge of electronic engineering and some programming
skills it will be easy to build your own touchscreen controller with a
microcontroller with buildin a/d converter, as resistive touchscreens are
really easy to measure/interface. You will find some of the offerend
ready controller chips aren't anymore than a standard microcontroller
with builtin adc.
As I use a touchscreen in my project too, I use an Atmel ATmega16 to
interface between touchscreen and host.

Hope that helps you.

Marco.

 

[Brian Kidney]

Thanks for the replies.

It looks like I might be able to get my hands on a 320x240 monochrome
display using the SED1335 controller chip (not sure of other details
yet). I have seen many examples of this using an 8051, has anyone had
any success using other uCs? If I do use a PIC, it will something
with a little horsepower from the 18F series.

Brian

 

[John Devereux]

Thanks for the replies.

It looks like I might be able to get my hands on a 320x240 monochrome
display using the SED1335 controller chip (not sure of other details
yet). I have seen many examples of this using an 8051, has anyone had
any success using other uCs? If I do use a PIC, it will something
with a little horsepower from the 18F series.

In principle you could use almost any microcontroller. But why not
take a look at some of the others out there? AVR, MSP430, ARM. Perhaps
something like the Philips LPC2138. Buy a low-cost development board
and hook it up to the display. Good community supported free tools
(including C compilers) are available for all the families mentioned.

 

[demmel]

Why don't you use one of our iLCD modules? They have touch scree
included and allow you make your project within days instead o
months - they have graphic support included and you may use an
(Windows) font stored in the flash memory of the module

[Sorry for doing something like advertising here

Best regard
Herber