Mega Discrepancy?

Development Boards MicroMod
1

Hi All,

I’ve got this display: http://www.electrokit.com/2-4-tft-lcd-t … uino.49420

It’s working on Standard UNO (5V) but just lit up on the Sparkfun Mega Pro (http://www.electrokit.com/mega-pro-5v-a … belt.49198).

I’ve cut the 3,3V feed as it is connected to 5V on Sparkfun Mega Pro 5V. Yes, Works on Uno with the cut! Tested all relevant outputs on the Mega, Working !

Anyone got a clue?

Regards

Peter

2

So what’s your question?

Check the pin mappings because the Uno is different from the Mega.

3

Well, apart from the above mentioned difference between 3,3 and 5V pins, the pin mappings are identical regading the pins used by the display.

Regards

Peter

4

Does the Sparkfun Mega Pro use different CPU pins to the corresponding digital and analog pins than the Arduino Mega? If so, that’d explain the discrepancy. Anyone knows?

Regards

Peter

5

The mega pro 5v page is https://www.sparkfun.com/products/11007

You can find the schematics there to check the pinout. There are also some comments about a wrong crystal being loaded; if that’s the case, timing could be off.

6

Got it working now. For further reference:

Two things needed:

  1. Uncomment USE_UNO_SHIELD_ON_MEGA in HW_Atmega1280.h

  2. Change UTFT myGLCD(ITDB24E_8, 19, 18, 17, 16); to UTFT myGLCD(ITDB24E_8, A5, A4, A3, A2);

Regards

Peter

7

Hello,

I noticed that you were having issues with sparkfun’s mega board working with a tft screen, but you were able to solve your problem. I am having a very similar issue using their mega pro mini 3.3V board. I tried following your solutions to the problem, but the libraries aren’t the same. The chip that’s used for this board is ATmega2560, so have you had any experience using it with a tft screen?