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