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package aio
import (
"math"
"time"
"gobot.io/x/gobot"
)
var _ gobot.Driver = (*GroveTemperatureSensorDriver)(nil)
// GroveTemperatureSensorDriver represents a Temperature Sensor
// The temperature is reported in degree Celsius
type GroveTemperatureSensorDriver struct {
name string
pin string
halt chan bool
temperature float64
interval time.Duration
connection AnalogReader
gobot.Eventer
}
// NewGroveTemperatureSensorDriver returns a new GroveTemperatureSensorDriver with a polling interval of
// 10 Milliseconds given an AnalogReader and pin.
//
// Optionally accepts:
// time.Duration: Interval at which the TemperatureSensor is polled for new information
//
// Adds the following API Commands:
// "Read" - See AnalogSensor.Read
func NewGroveTemperatureSensorDriver(a AnalogReader, pin string, v ...time.Duration) *GroveTemperatureSensorDriver {
d := &GroveTemperatureSensorDriver{
name: gobot.DefaultName("GroveTemperatureSensor"),
connection: a,
pin: pin,
Eventer: gobot.NewEventer(),
interval: 10 * time.Millisecond,
halt: make(chan bool),
}
if len(v) > 0 {
d.interval = v[0]
}
d.AddEvent(Data)
d.AddEvent(Error)
return d
}
// Start starts the GroveTemperatureSensorDriver and reads the Sensor at the given interval.
// Emits the Events:
// Data int - Event is emitted on change and represents the current temperature in celsius from the sensor.
// Error error - Event is emitted on error reading from the sensor.
func (a *GroveTemperatureSensorDriver) Start() (err error) {
thermistor := 3975.0
a.temperature = 0
go func() {
for {
rawValue, err := a.Read()
resistance := float64(1023.0-rawValue) * 10000 / float64(rawValue)
newValue := 1/(math.Log(resistance/10000.0)/thermistor+1/298.15) - 273.15
if err != nil {
a.Publish(Error, err)
} else if newValue != a.temperature && newValue != -1 {
a.temperature = newValue
a.Publish(Data, a.temperature)
}
select {
case <-time.After(a.interval):
case <-a.halt:
return
}
}
}()
return
}
// Halt stops polling the analog sensor for new information
func (a *GroveTemperatureSensorDriver) Halt() (err error) {
a.halt <- true
return
}
// Name returns the GroveTemperatureSensorDrivers name
func (a *GroveTemperatureSensorDriver) Name() string { return a.name }
// SetName sets the GroveTemperatureSensorDrivers name
func (a *GroveTemperatureSensorDriver) SetName(n string) { a.name = n }
// Pin returns the GroveTemperatureSensorDrivers pin
func (a *GroveTemperatureSensorDriver) Pin() string { return a.pin }
// Connection returns the GroveTemperatureSensorDrivers Connection
func (a *GroveTemperatureSensorDriver) Connection() gobot.Connection {
return a.connection.(gobot.Connection)
}
// Read returns the current Temperature from the Sensor
func (a *GroveTemperatureSensorDriver) Temperature() (val float64) {
return a.temperature
}
// Read returns the raw reading from the Sensor
func (a *GroveTemperatureSensorDriver) Read() (val int, err error) {
return a.connection.AnalogRead(a.Pin())
}
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