Interface, Happy or Sad Face?

Common interfaces between system microprocessors and integrated circuits (ICs) include SPI, I²C, and GPIO. This article discusses a common SPI error that can be almost impossible to find in a large system. Noise as a system issue is discussed and ICs that minimize its effects are mentioned. The trade-offs in an I²C system implementation are explained, and the basic operation of GPIO communication from a microprocessor is described. Links to tutorial information are provided for further reading.