2.4" Colour TFT Touch Screen and Adapter Board for Arduino (slipping away again)

Purchased one of the above 2.4" Colour TFT Touch Screen and Adapter Board for Arduino UNO and now find out that it uses every pin on the Uno.

https://www.google.co.uk/search?q=2.4%22+Colour+TFT+Touch+Screen+and+Adapter+Board+for+Arduino

Great (not).

Any suggestions as to what I can do with it now.

It might cover all the pins, but from the sketch posted on hobbycomponents forum it only uses 8 pins plus a 5v and ground pin. Could you upload the schematic for the adapter board? It's on hobbycomponents forum, I'm not a member there but I see you are and can access that schematic.

elac: It might cover all the pins, but from the sketch posted on hobbycomponents forum it only uses 8 pins plus a 5v and ground pin. Could you upload the schematic for the adapter board? It's on hobbycomponents forum, I'm not a member there but I see you are and can access that schematic.

I have the schematic and can confirm all the pins are used. I have also had a reply posted on the HobbyCompenents forum stating the same.

Can you post a link to the schematic you have found please?

I'm stuck t see how useful this can be if all the pins are used up :(

Alan

I have no schematic, I was referring to the sketch here as it only uses 8 pins plus 5v and ground. And the schematic here , if you could post that here to look at. Also if you can post the schematic to the LCD screen that will be helpful. You post all the relevant information and people here will be able to better help.

Good afternoon friends! this display does not use all the pins. I have the setting for one and mega256 platforms. I'll post here soon ok.

rogerio12: Good afternoon friends! this display does not use all the pins. I have the setting for one and mega256 platforms. I'll post here soon ok.

Looking forward to your posting. Is it the same screen/board or one of the other similar types? See http://forum.arduino.cc/index.php?topic=223769.msg1621352#msg1621352

Alan

acboother: Looking forward to your posting. Is it the same screen/board or one of the other similar types? See http://forum.arduino.cc/index.php?topic=223769.msg1621352#msg1621352

Alan

Assuming it is the above display (The google link you provide on #1 doesn't really show anything?) then you don't need all the uno pins.

You need 8 bits for data + 3 pins for control, assuming you don't need the touch functions.

This is the one I bought

http://www.ebay.co.uk/itm/141321869364?_trksid=p2059210.m2749.l2649&var=440442626135&ssPageName=STRK%3AMEBIDX%3AIT

Screen and adapter board.

If you follow the Google link in the first posting and select images you can see lots of them.

I think this is different to the one referred to on the other posting where the claims of being able to use/need only a moderate number of pins to make it work. May be 'inside' it is the same which would give me hope.

I wanted to use the screen and the touch functionality and hoping someone will say there is a way to release some pins so I can read some input (pressure sensitive buttons) and send some output (PWM to control a separate analog circuit). I'd even be happy to have it communicate with another Arduino which does all the interesting stuff and leave this one dedicated to the screen and touch functionality for user feedback and settings.

I expected it to leave me short of pins but zero pins is just ridiculous.

Still hoping there is a work around (and does not need moving to a MEGA either as I would like to keep it as small as possible).

Have some female jumper wires handy? Connect all the pins from the adapter board to the Uno that are defined in the sketch plus the 5V and ground, see if it works.

I am afraid the news are not the best.

That particular touchscreen uses SPI. So I believe you have pin A5, TX and RX (pins 0 and 1) and either pin 8, 9 and 10, depending on the configuration (one is the touch C/S, the other is the SD C/S and the remaining is free.

There are other screens whose touchscreen is multiplexed with the TFT control wires, leaving you the SPI pins free (assuming you don't need an SD Card).

Adafruit has a 2.8" display that can be used with SPI. Im sure they have a re seller in the UK, so have a look, that's a significant pin saving if you cant really go with a mega.

https://learn.adafruit.com/adafruit-2-8-tft-touch-shield-v2/connecting

I have attached the schematic and you can tick off every pin of the Arduino as being used… someone smarter than me might be able to identify some redundancy.

The Adafruit version looks better but it has (perhaps not surprisingly) a big uplift in price and not going to be suitable for a small production run even with a some form of discount for multiple purchases.

Assuming that there are no pins available what use is it as the library also takes a shed load of space on the Arduino and its going to be difficult to write an interesting sketch anyway?

Please let me/us know if you have done anything with this device.

schematic-2.4-v2.pdf (38.2 KB)

@ acboother Thread was split by mod, so to continue in your thread. No, I do not have or have used this 2.4" display, have a few 3.2" displays in projects. Are you using the SD card? If not using the SD card then you could try using those pins D10 -D13

As mentioned earlier its is an 8 bit, so regardless if they are being used or not you can get rid of some signals, such as the RD, CS and the reset, with the same applying to the SD card CS if you don't use it. The other pins you have to keep for the touchscreen. Google for what their purpose is, if you are not familiar. Whatever the case you have to re-wire the shield or get one of these:

(Check link below)

Even smarter, you could use the TFT CS to your favor. Add a buffer to drive some outputs and only write to them when you are not writing to the LCD. You can use the SPI BUS in the same way if you prefer to save some wires.

More than this I am afraid we wont be able to help. You could try to upgrade to a "bobuino" as a step between the uno and the MEGA

http://www.crossroadsfencing.com/BobuinoRev17/

Just found this display, which seems ideal for your application and cheap. Worth a look

http://www.ebay.com/itm/2-8-inch-320x240-Touch-TFT-LCD-Display-Module-SPI-16bit-8bit-all-Interface-/171201078046

casemod: Just found this display, which seems ideal for your application and cheap. Worth a look

http://www.ebay.com/itm/2-8-inch-320x240-Touch-TFT-LCD-Display-Module-SPI-16bit-8bit-all-Interface-/171201078046

There is one in the UK and whilst it says its for Arduino the sample code is for something else (although in plain C) and would require some untangling I think.

Have you interfaced this one with Arduino (the screen is the right size and its a good price so would be interested)?

Alan

Not that one in particular, I used the ILI9325 controller before with UTFT, so if you are familiar changing init routines it may well be worth it, otherwise I would do my research first on available libraries.

Right now I am pretty much only using SSD1289 and ST7781 controllers.

You might have to change the initialization routines to use it with SPI, based on the ILI9341 display. For parallel use you can use one of Adafruit libraries. I modified one some time ago to use a ILI9327 in 8 bit mode. The original code was for the ILI9325 in 8 bit mode.

https://www.youtube.com/watch?v=OWCfU--bXUI

Built a shield extender (lots of little legs) and experimented disconnecting pins...

Not using the SD card gives me digital pins D10 to D13 but cannot free any others if screen and touch wanted.

Removing touch gives back A0, A1 and D8, D9. These analog inputs will be useful and so moving to a ProMini or Nano will give two more pins A6 and A7 (not on a UNO). Also these take up a lot less space.

Hmmm. It may be possible to build a (physical) button user interface rather than the touchscreen one envisaged.

Slowly coming out of the doldrums with this project.

(In)sanity check going on…

  • The sample code shows 4 pins to instantiate the touch screen and another 4 pins for the LCD.
  • The schematic (using the shield) shows all the pins connected between Arduino and shield.
  • I can’t find any other reference to the other pins being used in the library code.
  • If the pins not used in the two instantiations are disconnected the touch screen or LCD doesn’t work.

So… what is it that these other pins do?

Anyone interfaced with this display without using the shield?

The shield does ‘level shifting’ (and possibly other things). If it is not possible to interface directly with the display could a home built level shifting shield be made? Would be useful as It could be made a more convenient size/shape for my project.

Shouldn't be a problem making your own shield, as the schematic is pretty straight forward. Grab four 74HC541PW chips, or three if your not using the SD card, and the voltage regulator, couple caps and resistors. If using a Pro mini you could include it right on the board.