Sending multiple data with SPI interface monitored by an Osciloscope
SPI.transfer(&amp;test[i],4);


The SPI.transfer() transmit one byte each time and therefore expecting a pointer to a byte (i.e. uint8_t) while you are passing in an address of an uint32_t. What you need to do is to cast the address of uint32_t into a pointer of uint8_t before passing it into the SPI.transfer.
uint8_t *ptr = (uint8_t *) &amp;test;

SPI.beginTransaction(SPISettings(20000000,MSBFIRST,SPI_MODE0 ));
digitalWrite(SPI_CS,LOW);
for (i = 0; i &lt; sizeof(test); i++) {
  SPI.transfer(*ptr++, 4);
}
digitalWrite(SPI_CS, HIGH);
SPI.endTransaction();

Please also note that Arduino is a little endian machine, so if you have a data as 0x41424344, the first byte get transmitted will be 0x44.
One more thing, it is always good to call SPI.endTransaction(), it free up the SPI bus to allow other SPI devices to use the data bus.