hybridgroup.gobot/drivers/gpio/pir_motion_driver.go

105 lines
2.5 KiB
Go

package gpio
import (
"time"
"gobot.io/x/gobot"
)
// PIRMotionDriver represents a digital Proximity Infra Red (PIR) motion detecter
type PIRMotionDriver struct {
Active bool
pin string
name string
halt chan bool
interval time.Duration
connection DigitalReader
gobot.Eventer
}
// NewPIRMotionDriver returns a new PIRMotionDriver with a polling interval of
// 10 Milliseconds given a DigitalReader and pin.
//
// Optionally accepts:
// time.Duration: Interval at which the PIRMotionDriver is polled for new information
func NewPIRMotionDriver(a DigitalReader, pin string, v ...time.Duration) *PIRMotionDriver {
b := &PIRMotionDriver{
name: "PIRMotion",
connection: a,
pin: pin,
Active: false,
Eventer: gobot.NewEventer(),
interval: 10 * time.Millisecond,
halt: make(chan bool),
}
if len(v) > 0 {
b.interval = v[0]
}
b.AddEvent(MotionDetected)
b.AddEvent(MotionStopped)
b.AddEvent(Error)
return b
}
// Start starts the PIRMotionDriver and polls the state of the sensor at the given interval.
//
// Emits the Events:
// MotionDetected - On motion detected
// MotionStopped int - On motion stopped
// Error error - On button error
//
// The PIRMotionDriver will send the MotionDetected event over and over,
// just as long as motion is still being detected.
// It will only send the MotionStopped event once, however, until
// motion starts being detected again
func (p *PIRMotionDriver) Start() (err error) {
go func() {
for {
newValue, err := p.connection.DigitalRead(p.Pin())
if err != nil {
p.Publish(Error, err)
}
switch newValue {
case 1:
if !p.Active {
p.Active = true
p.Publish(MotionDetected, newValue)
}
case 0:
if p.Active {
p.Active = false
p.Publish(MotionStopped, newValue)
}
}
select {
case <-time.After(p.interval):
case <-p.halt:
return
}
}
}()
return
}
// Halt stops polling the button for new information
func (p *PIRMotionDriver) Halt() (err error) {
p.halt <- true
return
}
// Name returns the PIRMotionDriver name
func (p *PIRMotionDriver) Name() string { return p.name }
// SetName sets the PIRMotionDriver name
func (p *PIRMotionDriver) SetName(n string) { p.name = n }
// Pin returns the PIRMotionDriver pin
func (p *PIRMotionDriver) Pin() string { return p.pin }
// Connection returns the PIRMotionDriver Connection
func (p *PIRMotionDriver) Connection() gobot.Connection { return p.connection.(gobot.Connection) }