Switch a light with one byte

A simulated Linux driver for the PCF8574 chip · Fontys ICT & Embedded Systems Open Day

1 · Build the commandtap a bit

2 · The chip's 8 pins0
All LEDs are off.
History
    3 · Inside the request
    The 3D view needs WebGL. The boxes below still show every step.
    History
      User space
      Your apppcf_demo
      libpcf8574builds the byte
      Linux kernel
      /dev/pcf8574system call
      pcf8574 driverremembers all 8 pins
      Hardware
      I2C bus2 wires
      PCF85748 pins
      LEDslight up

      What am I looking at?

      A computer can't switch a light directly. This page simulates how a program does it on Linux, with a driver Georgi Markov wrote for the PCF8574 chip, a small chip that gives a computer 8 extra switches.

      Building things like this is what you learn in ICT & Embedded Systems. The real driver runs on a Raspberry Pi at the stand. Source code on GitHub.

      Try it on your phone