ITDB02-3.2WC with Arduino Mega, resistors?

I bought the ITDB02-3.2WC http://iteadstudio.com/store/index.php?main_page=product_info&cPath=57_58&products_id=263 and want to use it without the shield. I have to add resistors, but i’m not completelly sure in which connections i need them. Is it correct, that i need to have 22k resistors in all connections (LCD, touch and sd card) except for 5V, 3.3V and GND? In all other 37 connections i have to put a 22k resistor? I searched for this topic but couldn’t find anything.
Thank you in advance for your help,

dusti

I am wondering about this too, i know that the screen needs 3.3V power, try looking at the schematic of the shield and see if you can figure out which pins lead to a resistor, the shield should be sold by the same site. I also am trying to research how to connect this without the shield, it is very hard to find concrete information on these cheap lcds

There seems to be no schematic of the shield, but i postet at iteadstudios website and got a response, but it didn't helped me much: http://iteadstudio.com/iforum/viewtopic.php?f=11&t=4531

These are the signal connections for the TFT part of the board:

DB0-DB15 REST RS WR RD CS

They all need to be driven at 3.3V, hence a resistor is required on each one when used with a 5V arduino or you will destroy the board.

In addition to these, connect up directly:

VCC=3.3V GND = GND LED-A = 5V

The ILI9327 is a nice one to work with, the data sheet is very good. The only annoyance I found is that the commands and parameters resolutely stick to 8-bits to be MIPI-compliant requiring multiple transfers when there's a nice 16-bit wide bus available.

Don't worry about the SD or the touch screen yet because you've got a big enough task ahead getting the LCD to work though I can tell you that SD levels are 3.3V.

RD goes to 3.3V, right? I now connected: DB0-DB15 to D22-D37 GND to GND VCC to 3.3V LED-Ato 5V RD to 3.3V RS to D38 WR to 39 CS to 40 Reset to D41

Its not working as expected. I uploaded the demo sketch "ITDB02_Graph16_Demo_Widescreen" from the ITDB02_Graph16 library from the website: http://henningkarlsen.com/electronics/library.php?id=39 After uploading the sketch i see nothing but a green/grey (hard to tell which color it is) screen with the background light turned on. The strange thing is the display does not change until i open the Serial monitor. Then the display shows an image painted with the code but its just a "snapshot" and not like a video (one should see lines appear etc as they are painted). I do not unterstand why this is happening because clearly i connected everything correct otherwise the display couldn't show a image at all. But why is the image updated when i open the serial monitor which has nothing to do with the display and is not used in the code at all. I added a "Serial.prinln("running..."); at the beginning of the main loop to see if the code is executed. I receive several "running..." with the serial monitor so i know the loop is executet at last once but nothing is drawn on the screen.

Can someone help me? I have no idea why this is happening and don't know how i can fix this strange behaviour.

Thanks in advance,

dusti

Got also some problems before I managed to get my 2.4D working.

First some disclaimer : I’m not sure at all that what I say here si correct. It’s just what I think at this moment.

  • The shield does NOT bring the 5V to 3.3. It only puts one 10k Resistor in series. Result is that the current is limited and the internal protection diodes in the 3.3V chip/LCD do not burn.
    Not very orthodox, but it seems to work
  • The documentation from iteadstudio is indeed very cryptic and incomplete. Apparently, the 2.4" and 3.2" are same resolution, but one is 8 bit and the other 16 bit. The shield is 16 bit,
    connects to 22-37 for D0-D15, RS, WR, CS, Reset to 38-41 as you did, so it should work.

I used ITDB02v1.3.rar from iteadstudio.com and after selecting the right LCD (2.4D) and setting it to 8 bits, the example sketches included worked fine.

Hi,

I am having the exact problem. And the very same thing happens when I open/close the serial monitor. The demo code appears to work on the screen less then a sec or so. But other then that I never see a thing on the screen.

I hope someone can help us with the problem. Thank you for the posts.

I can just confirm that my screen (with the shield from itead) works correctly.

Just a suggestion to investigate : I think that opening the monitor generates a reset, so maybe that's the reason. There is probably some reset circuitry as well on the LCD, and it is possible that at powerup the 3.3V regulator in the FT232 is not yet generating correctly at the end of the reset pulse ?

Hi,

I solved the problem by connecting resistors also to RS, WR, CS and RST pins of the display.

Here is the complete solution:


STEP - 1

LCD Module → Arduino UNO

DB8 - DB15 → D0 - D7 (with 10k resistors)
DB0 - DB6 → D8 - D13 (with 10k resistors)
DB7 - DB8 → A0 - A1 (with 10k resistors)
RST → A2 (with a 10k resistor)
CS → A3 (with a 10k resistor)
WR → A4 (with a 10k resistor)
RS → A5 (with a 10k resistor)
VCC → 5V (get it from Arduino’s 5V pin)
GND → GND (get it from Arduino’s GND pin)
RD → 3.3V (get it from Arduino’s 3.3V pin)
LED-A → 3.3V (get it from Arduino’s 3.3V pin)

STEP - 2

Download the CT_ITDB02_Graph16 library from:
http://www.henningkarlsen.com/electronics/download.php?f=CK_ITDB02_Graph16.rar

Go to example folder ITDB02_Graph16_Demo_Widescreen

Use the following line for creating the ITDB02 object in the pde file

ITDB02 myGLCD(19,18,17,16,ITDB32WC);


It worked for me. Hopefully it works for you also…

Thanks for the views and the posts…

Great to see you solved the problem. But it you build your own shield anyway, I'd suggest you try using bigger resistors. In another thread, someone said using 27k instead of 10k was OK. It reduces the risks /useless consumption by three. If I were you, I'd even try with 47k.

And indeed, Henning's libraries on http://henningkarlsen.com/electronics/library.php are incredible.