Real Time Clock and TFT screen interference

Hi

I'm in the middle of a project involving a RTC (DS3231) and a touch screen shield (2.4" TFT LCD Shield (9341) from mcufriend.com) with an Uno.

My problem is:
The time synchronization between the Uno and the RTC blanks out my screen, even though they do not share any pins. I set-up the RTC like this:

setSyncProvider(RTC.get);

And define a sync interval in seconds:
setSyncInterval(2*60); // Two minute sync interval

When it is time for the synchronization to occur (above, after two minutes), the screen goes completely white, but the Arduino (and the touch functionality) keeps running.

There is obviously some conflict between the two, but have not been able to figure out a way around the problem. As far as I understand, the RTC communicates on the I2C bus (connected to SCL and SDA), but why is this interfering with the screen (connected to the analog and digital pins)?

Either:
Solve the conflict between the two (best option)
or
Manually tell when to sync with some function call (can this be done?) and then reset the screen afterwards.

Does anyone out there have some input?

BR
Soren

LCD_RESET is on A4. On a Uno, SDA is also on A4.

Google for "Mcufriend I2C". I show you how to remove the LCD_RESET pin.

Perfect, thanks. I didn't want to mess with bitbanged I2C, so I just snipped the LCD_reset pin on the shield and rewired it to the Uno's reset.

Thanks again!