The I2C bus

In the previous chapter, we briefly touched on the I2C bus (or Inter-Integrated Circuit bus), which is a way to connect multiple devices together using just two wires. I2C was invented in the early 1980s by Philips as a way to link computer peripherals together using a common protocol. You can think of I2C as a kind of early form of USB.

I2C typically operates at relatively low speeds of up to 100kbit/s, compared to much faster interfaces such as Ethernet, which typically operates at up to 1Gbit/s, or USB, which can operate at up to 480Mbit/s. However, this is fast enough to connect basic sensors, display devices, or other peripherals such as real-time clocks—in fact; there are faster versions of the protocol that some devices will ...

Get Building a Home Security System with Raspberry Pi now with the O’Reilly learning platform.

O’Reilly members experience books, live events, courses curated by job role, and more from O’Reilly and nearly 200 top publishers.