Issue with running an RC522 and tft Touch screen on the same Mega

Using Arduino Project Guidance
#1

I have an Arduino Mega and I am using a tft touchscreen shield and RC522 with it as well. When I run with either just the touch screen or the RC522 RFID reader I am fine. But if I try and run both at the same time the tft screen just flashes black and white. I believe the 2 modules are some how interfering with each other. I have the tft touch screen on the standard shield pins and the RC522 is hooked up as follows:

RC522 - Arduino Mega
Vcc - 3.3v
Gnd - Gnd
IRQ - 51
SCK - 49
MOSI - 48
MISO - 47
NSS (SDA) - 50
RST - 46

Considering both the tft and the RC522 have sck pins I am wondering if these pins are interfering with each other thus causing the tft touch screen to fail. I posted my code but it is a full program so there is a lot of other stuff in it.

TFTRough.ino (23.1 KB)

#2

How do you power all these devices? I guess that the on-board regulators cannot power all those modules alltogether. Using 3.3V and 5V SPI or I2C modules together is calling for trouble.

Also make sure to configure all SPI modules for using different select pins.

#3

I am using the 3.3v pin on the mega, the regulator is cool to the touch. I don't think the power would be the issue. However I have a 4 amp 12 volt dc power supply with 3 busses at 12v, 5v, and 3.3v that would give ample power and the problem was still there. I just pulled the mega onto the work bench to make trouble shooting these 2 components easier.

#4