- +972 (0) 72 250 5555
The RS232/485 port consecutively sends and receives bytes filled with information one bit at a time. Although the serial method is somewhat slower than parallel communication, which allows the transmission of an entire byte at once, it is far simpler and can be employed over longer distances because power consumption is lower than that of parallel one. As an example, the IEEE 488 standard for parallel communication requires that the cabling between equipment can be no more than 20 meters total, with no more than 2 meters between any two connected devices.
I²C needs two lines, while SPI officially defines at least four signals or more if more servants are added. Some informal SPI alternatives only need three wires, that is an SCLK, SS and a bi-directional MISO/MOSI line. Nevertheless, this exercise would require one SS line per servant. SPI lacks further work, logic and/or pins if a multi-master engineering must be built on SPI. The singular problem I²C when building a system is a finite machine address space on 7 bits, overwhelmed with the 10-bits enlargement.