I'm working with a Waveshare TFT shield on an Arduino Mega 2560. I've actually made the screen display and the touch functions work pretty well using the Waveshare_ILI9486-2.0.0 library together with the Adafruit_GFX_Library. I haven't been able to get the BMP example to display pictures as yet but I don't particularly want to use that feature at the moment.
The project I'm working on is a Temperature and Humidity controller using an AM2302 DHt22 sensor and a Tiny RTC (I2C) module. I want the project to measure T/H, show the values with time and date on the LCD screen, control two digital outputs driving a fan and a ventilation duct servo and show status indicators/manual override buttons on the LCD screen. I have a sketch that does all of that really well and now I'd like to add a SD card module to write a file that records the data on a preset frequency.
I've tried using a Catalex micro SD card adaptor (v1.0, 11/01/2013) connected to pins 50, 51, 52 and 53 of the Mega (I previously had the project working using a 16 x 2 LCD display) and have it working except for the fact that the SD card module seems to conflict with the touch screen function because the push buttons don't work while the SD card module is connected. As far as my research tells me to date I don't believe there shouldn't be a problem running parallel SPI devices that use separate CS pins. Any advice on this would be appreciated.
Additionally, I'd like to know if the built-in micro SD card feature on the TFT shield could be used. I haven't any information about this at all other than an example sketch intended to show BMP images that doesn't work.