RelayController Library for PCF8574 The RelayController is a Python library for controlling relays through the PCF8574 I/O expander on platforms such as the Raspberry Pi. This library allows you to easily turn on, turn off, and toggle relays using I2C communication.

Features Turn on/off individual relays Toggle the state of individual relays Turn on/off all relays simultaneously Get the current state of all relays Installation To use the RelayController library, you need to have Python 3.x installed on your system as well as the smbus library which enables communication with I2C devices.

You can install the smbus library using pip:

bash Copy code pip install smbus Usage First, ensure that the I2C interface is enabled on your Raspberry Pi or compatible device.

Import the library and create an instance of the RelayController class:

python Copy code from RelayController import RelayController

Replace 0x20 with the I2C address of your PCF8574 module

relay_controller = RelayController(address=0x27) Turn a relay on or off by specifying its number (1-4):

Turn on relay 1

relay_controller.on(1)

Turn off relay 1

relay_controller.off(1)

Toggle relay 1

relay_controller.toggle(1)

Turn on all relays

relay_controller.on()

Turn off all relays

relay_controller.off()

Get the state of the relays

state = relay_controller.get_state() print(state) # Outputs a binary string like '0b11110000' Hardware Setup Make sure that the PCF8574 is properly connected to your Raspberry Pi's I2C pins (SDA and SCL), and that your relays are connected to the PCF8574. Check the datasheet for your specific relay module to ensure proper connections.

Support For support, please open an issue on the GitHub project page.