This guide shows you how to use PCF8574 with Raspberry PI. The PCF8574 is a 8 bits I/O port expander that uses the I2C bus. To the PCF8574 I will connect the relay module, this will allow control of the electrical device from the Raspberry PI. I will also show an example how to write a program to handle PCF8574 in C++ on Linux.
Each Friday is PiDay here at Adafruit! Be sure to check out our posts, tutorials and new Raspberry Pi related products. Adafruit has the largest and best selection of Raspberry Pi accessories and all the code & tutorials to get you up and running in no time!
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Featured Adafruit Product!
Raspberry Pi 3 – Model B – ARMv8 with 1G RAM – Did you really think the Raspberry Pi would stop getting better? At this point, we sound like a broken record, extolling on the new Pi’s myriad improvements like we’re surprised that the folks at the Raspberry Pi foundation are continuously making their flagship board better. Still, we’ll say it again – the Raspberry Pi team have outdone themselves. The Raspberry Pi 3 Model B is out and it is AMAZING. See More
Stop breadboarding and soldering – start making immediately! Adafruit’s Circuit Playground is jam-packed with LEDs, sensors, buttons, alligator clip pads and more. Build projects with Circuit Playground in a few minutes with the drag-and-drop MakeCode programming site, learn computer science using the CS Discoveries class on code.org, jump into CircuitPython to learn Python and hardware together, TinyGO, or even use the Arduino IDE. Circuit Playground Express is the newest and best Circuit Playground board, with support for CircuitPython, MakeCode, and Arduino. It has a powerful processor, 10 NeoPixels, mini speaker, InfraRed receive and transmit, two buttons, a switch, 14 alligator clip pads, and lots of sensors: capacitive touch, IR proximity, temperature, light, motion and sound. A whole wide world of electronics and coding is waiting for you, and it fits in the palm of your hand.