UART
SPI

SCLK - Serial clock (Output from master)

MOSI - Master Out Slave In (Data output from master)

MISO - Master In Slave Out (Data output from slave)

SS or CS - Slave select or Chip select (often an active-low signal, output by the master)
The communication principle is that the master device sends data to the listening slave device
through the MOSI line. The slave can read this data while simultaneously returning data to the
master device through the MISO line, where the master can read it. This is how the full-duplex data
transmission occurs.
Usually, this communication involves the use of 8-bit size registers, with the first bit being the MSB
(Most Significant Bit). Both master and slave shift one bit forward through the register and outputs
the last bit on the clock edge.
When the transmission is complete, the master device deselects the slave by pulling the
corresponding slave select pin high.
Although SPI data transmissions often comprise 8-bit messaging, other word sizes, such as 16-bit, are
also in common use for applications such as touchscreen controllers of audio codecs.
İ2C
TCP/IP