I²C vs SPI Today, at the low end of the communication protocols, we find I²C (for ‘Inter-Integrated Circuit’, protocol) and SPI (for ‘Serial Peripheral Interface’). Both protocols are well-suited for communications between integrated circuits, for slow communication with on-board peripherals.

Inter-Integrated Circuits – I2C Basics. Iatkos Ml2 Iso To Usb Windows on this page. Hello folks, it’s time for I2C! Currently, related to Serial Communication, maxEmbedded features RS232 and SPI communication.

At the roots of these two popular protocols we find two major companies – Philips for I²C and Motorola for SPI – and two different histories about why, when and how the protocols were created. The I²C bus was developed in 1982; its original purpose was to provide an easy way to connect a CPU to peripherals chips in a TV set. Peripheral devices in embedded systems are often connected to the microcontroller as memory-mapped I/O devices. One common way to do this is connecting the peripherals to the microcontroller parallel address and data busses. This results in lots of wiring on the PCB (printed circuit board) and additional ‘glue logic’ to decode the address bus on which all the peripherals are connected. In order to spare microcontroller pins, additional logic and make the PCBs simpler – in order words, to lower the costs – Philips labs in Eindhoven (The Netherlands) invented the ‘Inter-Integrated Circuit’, IIC or I²C protocol that only requires 2 wires for connecting all the peripheral to a microcontroller. The original specification defined a bus speed of 100 kbps (kilo bits per second).