SPI with VSPI & HSPI (or is that irrelevant?)

Using Arduino Programming Questions
1

I try to build something on a Cheap Yellow Display device. So far, I have programmed the display and reading a file from a SD-Card.
I now want to use Touch, but have some issues. I always read the maximum values, event if it's not touched at all.

I assume it's because the SPI for accessing the SD-Card. I was able to run an example TouchTest sketch, but when I add the same code to my main sketch it's not working.
There's also some hint that the sd-card is using VSPI while the display is using HSPI (no idea, if that has something to do with my issue).

Here's the extract (which I assume is part of the issue):

#include <SPI.h>
#include <SD.h>
#include <XPT2046_Touchscreen.h>
#include <TFT_eSPI.h>

#define XPT2046_IRQ 36
#define XPT2046_MOSI 32
#define XPT2046_MISO 39
#define XPT2046_CLK 25
#define XPT2046_CS 33

SPIClass touchSpi = SPIClass(VSPI);
XPT2046_Touchscreen ts(XPT2046_CS, XPT2046_IRQ);
TFT_eSPI tft = TFT_eSPI();

void setup() {
  // TOUCH
  touchSpi.begin(XPT2046_CLK, XPT2046_MISO, XPT2046_MOSI, XPT2046_CS);
  ts.begin(touchSpi);
  ts.setRotation(1);

  // TFT_eSPI
  tft.init();
  tft.setRotation(1);

  if (SD.begin(5) && SD.exists("/setlist.csv")) {
    // …
  }
}

void loop() {
  if (ts.tirqTouched() && ts.touched()) {
    TS_Point p = ts.getPoint();
    printTouchToSerial(p);
    delay(100);
  }
}

void printTouchToSerial(TS_Point p) {
  Serial.print("Pressure = ");
  Serial.print(p.z);
  Serial.print(", x = ");
  Serial.print(p.x);
  Serial.print(", y = ");
  Serial.print(p.y);
  Serial.println();
}

The output is always:

Pressure = 4095, x = 8191, y = 8191

I pushed my changes to gitlab (or take a look at the changeset) for the full source-code.

I'd be happy for some ideas.

2

Have you used the sample sketches to prove that the touch panel works?

3

Yes, the sample is working (Touchtest)

4

many common SD card have problem sharing an SPI bus with other devices, see sdspi_share problems

have a look at connecting-sd-card-and-bmp280-via-spi-interface which is a ESP32 example using a SD card on VSPI and a MRFC522 RFID reader on HSPI

5

Looks like both SD and TFT use the same VSPI bus.
The global variable "SPI" defaults to VSPI bus.

6

suggest run the SD on the VSPI and move the TFT to HSPI