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Author Topic: 7" LCD or similar  (Read 2848 times)
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Hi,

I have read a little on the forum about the use of big screens, and the common answer is that it is not possible due to image size on that big screen resolutions.

However, due to the amount of text I have to show (yes: only text), I need a big screen, something in the line of 7". I've found on RS a color LCD screen with 7" and tactile sensor for 70€. I think it needs a lot of pins, something like 16 or 18.
But: It is possible to do it with a Mega?

Any library suggested?
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this can work if you get a screen with vga input:
https://www.sparkfun.com/products/10329

or composite video connection:
https://www.sparkfun.com/products/9313
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I was thinking in something like that:

http://uk.rs-online.com/web/p/lcd-displays-colour-graphic/7502588/?searchTerm=750-2588&relevancy-data=636F3D3126696E3D4931384E525353746F636B4E756D6265724D504E266C753D656E266D6D3D6D61746368616C6C26706D3D5E5C647B337D5B5C732D2F255C2E5D5C647B332C347D2426706F3D313426736E3D592673743D52535F53544F434B5F4E554D424552267573743D3735302D323538382677633D4E4F4E4526

I don't know if it has the controller/buffer integrated, for what I read yes, but I don't know at what level or if it is useful, I'm not an expert on this matter. smiley-lol.
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Larger LCD screens all use VGA or VGA-like interfaces - there is no screen buffer so you have to have a VGA-like driver to interface to them.

Small LCD screens (upto about 320x240) can have framebuffer chips like the ILI9325.  These often have a simple-to-use serial or SPI interface which is easy to drive from a microcontroller (no requirement for constant refresh).

The reason for the difference between large and small screens is simple - the smaller screens have a _single_ silicon chip controller which controls source and gate lines to the TFT LCD pixels - thus it can drive pixel data from a frame buffer to the right screen pixel.

Larger screens have separate (often multiple) chips for source lines and for gate lines.  No one piece of silicon knows both the row and column information so there's nowhere to put a framebuffer (other than in an external VGA-generator chip).

With VGA style interfaces the source driver(s) handles Hsync and does serial->parallel conversion for one row at a time. The gate driver(s) handle Vsync and selecting the current row.
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Oslo, Norway
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You can use that screen with an Arduino Mega (probably even an Arduino 2009/Uno but it will most likely use ALL the available pins.)
The product information clearly states:
  • Built in controller
  • 8080/6800 MCU Interface (selectable)
But don't expect fast updates smiley

/Henning
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Thanks so much for your answers.

The idea it's to use one Atmega for the screen and control panel interface (input buttons) and another ATmega for the motors and internal machine I/O.
So with the two ATmega I want to create a NC control system for machines.
And NC control it's like a CNC but closed, you don't have the ability to send G code outside, it is all pre-programmed.

I was looking also at the matrix LED displays, but even it can show a lot of text, the screen is too small.
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Thanks so much for your answers.

The idea it's to use one Atmega for the screen and control panel interface (input buttons) and another ATmega for the motors and internal machine I/O.
So with the two ATmega I want to create a NC control system for machines.
And NC control it's like a CNC but closed, you don't have the ability to send G code outside, it is all pre-programmed.
Given you are thinking of two separate controllers now, you might think of something like an Android tablet to do the I/O, and connect up with your motor controller via bluetooth or maybe a wired approach via the USB port.  Looking at the Android play store on my phone, I see quite a few options that are free or fairly cheap that would allow you to control an Arduino without having to learn to Android programming.

Or you can add a wifi shield, and have the motor controller export a web site, and just use a browser on the tablet/phone/pc.
« Last Edit: October 31, 2012, 07:30:00 am by MichaelMeissner » Logged

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That particular module has an SSD1963 controller with built in 1215KB framebuffer - see datasheet for controller: http://www.allshore.com/pdf/solomon_systech_ssd1963.pdf - so it is easy to interface too, relatively speaking.  The controller is mounted on a separate board to the display itself and will be sending digital VGA-style signals to the integral display driver chips.
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Nice! Ordered, Should have it on Monday.
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Why not do something like this?

with something like this. http://store.mp3car.com/Lilliput_7_Inch_USB_WVGA_UM_70C_Monitor_p/mon-106.htm
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Hi,

I have this 7" TFT (http://dx.com/p/i082510-800-x-480-7-tft-touch-screen-module-153336) and works fine in Arduino, except because the image show mirrored (probably is a problem with the graphic libray: uTFT).
The display has a touch pannel, and a SD card reader.

Use 20 pins of Arduino (and 2 for the power, of course), so you can use the Arduino MEGA without problems...

Regards,
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(probably is a problem with the graphic libray: uTFT).

The "problem" is that you have not read the list of supported display modules supplied with UTFT!

/Henning
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(probably is a problem with the graphic libray: uTFT).

The "problem" is that you have not read the list of supported display modules supplied with UTFT!

/Henning

Hi,

First, thanks for your NO-help...
I read the doc (obviously) before my post, and the controller of my display (SSD1963) is in the list of supported controllers of the UTFT library... so please, the next time, read YOU the list before post this kind of replies...

Regards,
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First, thanks for your NO-help...

You are very welcome...

I read the doc (obviously) before my post, and the controller of my display (SSD1963) is in the list of supported controllers of the UTFT library... so please, the next time, read YOU the list before post this kind of replies...

If you read the documentataion like you say you would have found that the controller is supported but no 7" display modules are supported.
You are getting an image on the display so the controller part is obviously working, but the image is not what you expected because your particular display module is NOT supported.
Therefore the problem is not with the library.

I have put a lot of time and effort into my libraries and do not like it when people like you make unfounded accusations that there are problems with them. All the display modules on the supported-list work just fine. Because there are differences between modules I need to have one of the module in question to add support for it.

/Henning
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I read the doc (obviously) before my post, and the controller of my display (SSD1963) is in the list of supported controllers of the UTFT library... so please, the next time, read YOU the list before post this kind of replies...

If you read the documentataion like you say you would have found that the controller is supported but no 7" display modules are supported.
You are getting an image on the display so the controller part is obviously working, but the image is not what you expected because your particular display module is NOT supported.
Therefore the problem is not with the library.

I have put a lot of time and effort into my libraries and do not like it when people like you make unfounded accusations that there are problems with them. All the display modules on the supported-list work just fine. Because there are differences between modules I need to have one of the module in question to add support for it.

Well... I think this was not a good start...
My english is not very good, so maybe you are right, but when I read your post, I didn't like the response...
In any case, I apologies for my answer...

I use the UTFT library a lot of times, and always works great... but in this case, I was searching a "big" TFT to use in my Arduino project, and when I found this display, and I saw the controller was compatible with the library, I was very dissapointed because the image shows fine, but mirrored...

This is the reason because I was thinking in a library problem... but ok, you are right... is not  a library problem. It was just a comment, and I didn't want make unfounded accusations. Your library is very usefull for me, and I'm very grateful with that.

Regards,
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