Uno and 7" LCD

Hey all.
First post, Wooo! :slight_smile: XD :smiley:

Anyway, Im seeking some help with a project im working on, It requires the use of a 7" Touch TFT LCD. The model I have chosen is a 60 pin connector.
Of those, Only 24 need to be connected to Arduino.
4 Touch inputs, X-,X+,Y-,Y+, Analog?
RESET, CS, DC?, RD, WR, DB0-15.
Im basing my schematic off the Adafruit 2.8" touch breakout board, but that only has DB0-7. Do I just connect the rest of the DB pins(8-15) to their respective pins, or do I leave them out?
I know it wont fit on an Uno, But if the whole DB0-15 pin set needs to be used, Ill be ordering my Mega.
When the project is done, It will be moved over to an Arduino Mega, Im only using Uno while I learn.
Will I also be able to use an existing LCD library, or will I need to somehow make my own?

In summary,
Do all 16 DB pins need to be used?
Can I use an exsisting graphics library, or will I need to make my own?
Does anybody know of an Arduino compatible 7" touch TFT LCD, one with an existing graphics library?

Thanks for the help

Datasheet: http://www.farnell.com/datasheets/1444177.pdf

Is that the first display you found? where have you looked? (so we don't have to duplicate your hard work)
And as a question that needs, I think to be asked is... Did you search for 7" display's... For an Arduino?
On Ebay?

Docedison:
Is that the first display you found? where have you looked? (so we don't have to duplicate your hard work)
And as a question that needs, I think to be asked is... Did you search for 7" display's... For an Arduino?
On Ebay?

Yes that is the best one I have found.
I have searched on ebay, electronic sellers(Element14, ElecFreaks, etc) and local sellers(Gumtree, Craigslist)
Yes, I did search 7" displays for Arduino on ebay, None were touch.

That display is 3.3V logic and 16 bit parallel only, so you'll need 21 pins to talk to it....

A 5V display with 8bit parallel support would be easier...

One way to reduce the pin count is a couple of 74HC595 shift registers (run at 3V3) to drive the 16 bit databus
using the Arduino SPI hardware, and then you'll only need about 8 level shifters rather than 21.

MarkT:
That display is 3.3V logic and 16 bit parallel only, so you'll need 21 pins to talk to it....

A 5V display with 8bit parallel support would be easier...

One way to reduce the pin count is a couple of 74HC595 shift registers (run at 3V3) to drive the 16 bit databus
using the Arduino SPI hardware, and then you'll only need about 8 level shifters rather than 21.

I should be able to just use it with a mega though without needing the shift registers?
They are only needed to drop the pin count down to something an Uno can manage?

21 level shifters???

Use a Due.


Rob

MarkT:
21 level shifters???

Why would these be needed? Im new to this whole side of electronics but I did my research, and they are used when changing voltages right? But the LCD runs on 3.3V and the Arduino supports 3.3V.

Graynomad:
Use a Due.

Any particular reasoning behind this?

But the LCD runs on 3.3V and the Arduino supports 3.3V.

Most Arduinos are 5v, they should read 3v3 as a high but they will send 5v to your LCD, not recomended.

Any particular reasoning behind this?

Because it does support 3v3, and has a lot of IO.


Rob

Graynomad:

But the LCD runs on 3.3V and the Arduino supports 3.3V.

Most Arduinos are 5v, they should read 3v3 as a high but they will send 5v to your LCD, not recomended.

Any particular reasoning behind this?

Because it does support 3v3, and has a lot of IO.

I was going to get getting a Mega for the final project anyway, I guess the extra power of the new ARM core would help quite a bit.
One question that got lost though was if I can use a pre-existing LCD library like GFX or GLCD etc. with my selected display?

Sorry I've no idea about the libraries. At the very least I think you'd have to write low-level drivers for the Due (unless someone has already done that).

As for weather they support your display, you'd have to look on the relevant sites. If your display uses a common controller chip you are probably in luck with support at that level.


Rob

Graynomad:
Sorry I've no idea about the libraries. At the very least I think you'd have to write low-level drivers for the Due (unless someone has already done that).

As for weather they support your display, you'd have to look on the relevant sites. If your display uses a common controller chip you are probably in luck with support at that level.


Rob

Thanks for the help :slight_smile: