Hi, I'm curious too. I have read about UART and USART, I2C, SPI.
For all I know, SPI was developed to provide relatively high-speed, short distance communication using a minumum number of microcontroller pins. How fast is it? How many clock cycle for 1 byte of communication, as compared to I2C?
Since it uses hardware cycle, doesthat means my main program will execute with no delay?
Pardon me, i come from a mechanical background, I'm concern about the performance of SPI right now. I search through to web but nothing was mention. Maybe because it's common, and I would like to find out.