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ESP8266/ESP3232: Home Assistant Switch Connected to PCF8574 Controlling 8 AC Relays

February 24, 20194 min read

📺 Watch the Video View on YouTube --- Home Assistant Switch for 8 Relays: PCF8574 can be used to extend the GPIO of ESP8266/32 and here we use 8 port...

ESP8266 ESP32 Home Assitant IoT MQTT WiFi relay sensor+2

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Home Assistant Switch for 8 Relays: PCF8574 can be used to extend the GPIO of ESP8266/32 and here we use 8 ports of PCF8574 to control 8 Relay module

GitHub: debsahu/PCF8574_8Relay

Home Assistant Switch for 8 Relays

Code can compile on ESP8266/32
PCF8574 can be used to extend the GPIO of ESP8266/32
8 ports of PCF8574 is connected to 8 Relay module

Libraries Needed

platformio.ini is included, use PlatformIO and it will take care of installing the following libraries.

Library	Link
MQTT	https://github.com/256dpi/arduino-mqtt
ArduinoJson v6	https://github.com/bblanchon/ArduinoJson
WiFiManager Develop	https://github.com/tzapu/WiFiManager/archive/development.zip
PCF8574 Library	https://github.com/xreef/PCF8574_library
Arduino WebSockets	https://github.com/Links2004/arduinoWebSockets
UpdateUploadServer (ESP8266)	https://github.com/debsahu/DDUpdateUploadServer

Hardware

Items

ESP8266 (aliexpress) / ESP32 (aliexpress)
3.3V to 5V converter (aliexpress)
PCF8574AP (aliexpress)
8-port relay (aliexpress)
Plastic Box (amazon)
AC plug socket (aliexpress)
3-pin AC cable (aliexpress)
2 sockets (Home Depot)

Instructions

Break the tab on the sides with brass screws
Connect each of the brass screws to Normally Open (N/O) on relay

plug

Use PCF8574AP (exact version used here)
Use 3.3V to 5V level shifters for ESP8266 I2C data
Set A0, A1, A2 to GND so I2C address is 0x20
Use 5V as VCC on PCF8574AP
Use a good 110V AC to 5V DC device like a phone charger

schematic

Technologies Used

ESP8266 ESP32 Home Assitant IoT MQTT WiFi relay sensor switch debashish sahu

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