ESP8266/32 (Home Assistant Switch) connected to PCF8574 controlling 8 relays
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
- 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
