Struct Relay 

pub struct Relay {
    pub value: bool,
    /* private fields */
}

Controls a relay output on the Automation HAT.

Each relay provides a high-power switch controlled by the Raspberry Pi. Relays have both normally open (NO) and normally closed (NC) terminals, which can be used to switch external circuits.

Fields

value: bool

Current state of the relay (true = activated/on, false = deactivated/off)

Implementations

impl Relay

pub fn new(line: Line, no_led: Option<LED>, nc_led: Option<LED>) -> Self

Creates a new relay instance with automatic LED indication enabled.

Arguments

• line - GPIO line connected to the relay
• no_led - Optional LED for the normally open contact indicator
• nc_led - Optional LED for the normally closed contact indicator

Returns

A new Relay instance configured with automatic LED indication

pub fn new_with_auto_light( line: Line, no_led: Option<LED>, nc_led: Option<LED>, auto_light: bool, ) -> Self

Creates a new relay instance with configurable LED indication.

Arguments

• line - GPIO line connected to the relay
• no_led - Optional LED for the normally open contact indicator
• nc_led - Optional LED for the normally closed contact indicator
• auto_light - Whether LEDs should automatically reflect relay state

Returns

A new Relay instance with the specified LED behavior

pub fn write(&mut self, open: bool) -> Result<(), &str>

Sets the state of the relay.

When open is true, the relay is activated:

• The normally open (NO) contacts close
• The normally closed (NC) contacts open
• If auto_light is enabled, the NO LED lights up and NC LED turns off

When open is false, the relay is deactivated:

• The normally open (NO) contacts open
• The normally closed (NC) contacts close
• If auto_light is enabled, the NO LED turns off and NC LED lights up

Arguments

• open - The desired state of the relay (true = activated, false = deactivated)

Returns

A Result indicating success or an error message if the operation failed