Control SD Module and TFT Display

Hi,
I want to control an external SD-Card-Module and a TFT-Display at the same time. The problem is, that the pins sometimes the same for the display and SD-Card-Module. Can anyone help me?

PS. I don´t want to buy a TFT Display with SD slot

If there is a conflict, simply change the pin assignments in the code.

For informed help, please read and follow the directions in the "How to use this forum" post.

The code doesn´t allow it.

If the TFT module is a SPI device, the SCK, MOSI and MISO pins are shared between the display and the SD module on the SPI bus.

One thing to be aware of if both devices are SPI. Some SD card modules will not play well with other devices on the SPI bus. The problem is with the way the level shifter on the SD module is wired. The ones that do not work well have the MISO signal running through the level shifter. That causes the MISO signal to not be released so that the other devices can control it. The modules made by Adafruit (and some others) have the MISO signal going from the SD card straight to the MISO, bypassing the level shifter. Look at the schematic for the Adafruit module to see what to look for. DO (data out) is the MISO signal.

Better help if you post links to the TFT display and the SD card module that you are using.

For informed help, please read and follow the directions in the “How to use this forum” post

Hi,
I am using this SD Module: Link
And this Display: Link

nilsfast:
The code doesn´t allow it.

Why do you say that?

Post your code, using code tags, and post the error messages, also using code tags.

The SD-card uses the SPI interface and the display uses I2C.

There is no valid reason for a pin conflict.

I don't understand Which pins do I have to connect?

I'm confused. The link nilsfast gives to the display appears to say it is SPI, but the pinout below that is for I2C. So it's not clear which it is. If the display is I2C, then there should be no pins in common with the SD module. If it's SPI, then see groundFungus' post above - the SD module isn't letting go of MISO when it's CS is off.

If not already done, I think the first thing is to get each device working independently.

Yes, the display link causes some confusion.

There are several different interface versions of the ST7735 display controller (including but not limited to SPI and I2C) so the OP must figure out what he/she actually has.

But even if both items use the SPI bus, that does not mean there is a pin conflict.

I think the first thing is to get each device working independently.

Agreed.

I got it to work. I don't know, what I did, but now it works, thank you for all of your help!

Please try to think what you changed that made it work and describe it in this thread. Other forum members in the future could learn from your mistakes.