#pcf8574

In my last tutorial, I talked about the TCA9548A MUX which can be used to add at the max of 64 I2C or I²C sensors to your Arduino/ESP8266/ESP32.In this tutorial, I am going to talk about the PCF8574 8-bit GPIO Port Extender. It is one of the many GPIO extenders available in the market.This tiny little board becomes a life saver When you run out of pins on your Arduino. This "GPIO (General Purpose Input Output) pin extender" provides an additional 8 pins (P0 ~ P7) which can be used to 'output a signal' or 'read a signal as an input'.These modules run on the I2C bus, and if daisy-chained you can connect upto 8 of these devices in a project. Each device will give us an additional 8-bits of GPIO enabling 64 GPIOs in total.These ICs are ridiculously cheap and can be bought easily from eBay or AliExpress. If you don't want to worry about the wiring and just want to keep your project really "simple", then you can buy these fully assembled breakout boards. You just need to hook them up to the I2C bus and you are all ready to go.

Blog Post: https://diyfactory007.blogspot.com/2018/12/pcf8574-gpio-extender-with-arduino-and.html

I2C interfacing of 16x2 lcd is better option to try if want to reduce wiring headache and want to save pins of Arduino. It takes only two pins to established communication for data transfer(SCL, SDA) ______________________________________________ #16x2lcd #PCF8574 #i2c #display #Arduino #interfacing #liquidcrystaldisplay #electronics #circuit #circuitdesign #circuitboard #programming #arduinouno #coding #microcontroller #electronic #hardware #embeddedsystem #engineering #design #makers #DIYProject #diy https://www.instagram.com/p/ByQLM3PJ_KA/?igshid=1w1aesoa9umik

#nodemcu #esp8266 #pcf8574 #iot #relay

[I2cDiscreteIoExpander](https://github.com/4-20ma/I2cDiscreteIoExpander) is an Arduino library for the Texas Instruments PCF8575C 16-bit I2C I/O expander. The PCF8575C provides general-purpose remote I/O expansion for most microcontroller families via the I2C interface serial clock (SCL) and serial data (SDA). The device features a 16-bit quasi-bidirectional input/output (I/O) port (P07..P00, P17..P10), including latched outputs with high-current drive capability for directly driving LEDs. Each quasi-bidirectional I/O can be used as an input or output without the use of a data-direction control signal. At power on, the I/Os are in 3-state mode. The strong pullup to VCC allows fast-rising edges into heavily loaded outputs. This device turns on when an output is written high and is switched off by the negative edge of SCL. The I/Os should be high before being used as inputs. After power on, as all the I/Os are set to 3-state, all of them can be used as inputs. Any change in setting of the I/Os as either inputs or outputs can be done with the write mode. If a high is applied externally to an I/O that has been written earlier to low, a large current (IOL) flows to GND. The fixed I2C address of the PCF8575C is the same as the PCF8575, PCF8574, PCA9535, and PCA9555, allowing up to eight of these devices, in any combination, to share the same I2C bus or SMBus. Full [source code documentation](http://4-20ma.github.com/I2cDiscreteIoExpander/) is available.