Package Relay provides functionality for employing an AC relay from a microcontroller, expects to be compiled with TinyGo, and implements the Triggerable interface.
type Triggerable interface {
Name() string
Execute(t Trigger)
}When a Dispatcher receives a Trigger intended for a Relay it knows about, it calls the Relay's Execute method, passing along the Trigger.
If the Trigger.Duration is omitted, the Trigger.Action is interpreted as having indefinite duration. If a duration is included, the Relay's Execute method will spawn a goroutine that keeps the Relay's pin high for the intended duration.
Subsequent Triggers received during the Relay's on duration will revise the intended duration, and if the new duration would be shorter than the time already elapsed, it will turn off the Relay, bringing its pin low and stopping the goroutine.
Create & configure a new Relay
r := relay.New(machine.D2, "KitchenLights")
r.Configure()Create a Dispatcher and pass it a channel on which it should listen for Triggers
ch := make(chan Trigger, 1)
d := trigger.NewDispatch(ch)Add your Relay to the Dispatcher and start dispatching
d.AddToDispatch(r)
go d.Dispatch()Triggers can be sent via MQTT. If your MQTT handler sends messages to your Dispatcher, it will determine which of its Triggerables should execute the Trigger.
We can emulate this by creating a Trigger and sending it to our Dispatcher's channel:
t := trigger.Trigger{}
t.Target = "KitchenLights"
t.Action = "On"
t.Duration = time.Duration(30 * time.Second)
ch <- tThe above snippet may fail because we haven't set t.ReportCh – a chan Trigger to which the Relay's Execute method will send the modified Trigger after taking the requested action. Specifically, Execute will typically send the Trigger back to the MQTT handler, having updated t.Message and possibly having set t.Error.