Python Library

Turta_Relay library is responsible for controlling onboard relays.

Initialization

Add the following statement to the top of your Python code.

from turta_relayhat2 import Turta_Relay

Then, create an instance of the RelayController class.

relay = Turta_Relay.RelayController()

Now you're ready to access the library by calling its instance.

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Advanced Initialization

There are three advanced initialization parameters.

relay = Turta_Relay.RelayController(addr = 0x20, leds_state = True, preserve_state = False)

• Parameters

  • Byte addr: Device address. 0x20 to 0x27. Default is 0x20.

  • Bool leds_state: True to enable, False to disable indicator LEDs. Default is True.

  • Bool preserve_state: Keeps relay states as they are, even if you reboot the Raspberry Pi. Default is False.

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Stacking Relay HATs

If you're stacking Relay HATs, create an instance for each board.

relay_1 = Turta_Relay.RelayController()     # Default 0x20 address
relay_2 = Turta_Relay.RelayController(0x21) # Other board
...
relay_8 = Turta_Relay.RelayController(0x27) # Last board

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Basic Members

Write (Control) Relay

Controls the relay.

write(ch, st)

• Parameters

  • Byte ch: Relay channel. (1 to 5.)

  • Bool st: Relay state. (True or False.)

• Returns

  • None

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Write Once to Relays

Controls all the relays in one command.

write_once(st)

• Parameters

  • Byte st: Relay states. (0b00000 to 0b11111.)

• Returns

  • None

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Write (Control) All Relays

Turns on or off all the relays.

write_all(st)

• Parameters

  • Bool st: Relay states. (True or False.)

• Returns

  • None

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Toggle Relay

Inverts the relay's state.

toggle(ch)

• Parameters

  • Byte ch: Relay channel. (1 to 5.)

• Returns

  • None

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Toggle All

Inverts all the relay states.

toggle_all()

• Parameters

  • None

• Returns

  • None

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Read Relay

Reads the relay state.

read(ch)

• Parameters

  • Byte ch: Relay channel. (1 to 5.)

• Returns

  • Bool: Relay state. (True or False.)

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Read All Relay States

Reads all the relay states.

read_all()

• Parameters

  • None

• Returns

  • Byte: Relay states. (0b00000 to 0b11111.)

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Advanced Members

Set Indicator LEDs

Enables or disables the indicator LEDs. Useful if you're stacking a few Relay HATs.

set_leds(st)

• Parameters

  • Bool st: Indicator LEDs state. (True or False.)

• Returns

  • None

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Finalizer

When exiting from the program, the library sets all the relays off if preserve state setting is not enabled.