gobot.io/x/gobot@v1.16.0/drivers/aio/analog_actuator_driver.go (about)

     1  package aio
     2  
     3  import (
     4  	"strconv"
     5  
     6  	"gobot.io/x/gobot"
     7  )
     8  
     9  // AnalogActuatorDriver represents an analog actuator
    10  type AnalogActuatorDriver struct {
    11  	name       string
    12  	pin        string
    13  	connection AnalogWriter
    14  	gobot.Eventer
    15  	gobot.Commander
    16  	scale        func(input float64) (value int)
    17  	lastValue    float64
    18  	lastRawValue int
    19  }
    20  
    21  // NewAnalogActuatorDriver returns a new AnalogActuatorDriver given by an AnalogWriter and pin.
    22  // The driver supports customizable scaling from given float64 value to written int.
    23  // The default scaling is 1:1. An adjustable linear scaler is provided by the driver.
    24  //
    25  // Adds the following API Commands:
    26  // 	"Write"    - See AnalogActuator.Write
    27  // 	"RawWrite" - See AnalogActuator.RawWrite
    28  func NewAnalogActuatorDriver(a AnalogWriter, pin string) *AnalogActuatorDriver {
    29  	d := &AnalogActuatorDriver{
    30  		name:       gobot.DefaultName("AnalogActuator"),
    31  		connection: a,
    32  		pin:        pin,
    33  		Commander:  gobot.NewCommander(),
    34  		scale:      func(input float64) (value int) { return int(input) },
    35  	}
    36  
    37  	d.AddCommand("Write", func(params map[string]interface{}) interface{} {
    38  		val, err := strconv.ParseFloat(params["val"].(string), 64)
    39  		if err != nil {
    40  			return err
    41  		}
    42  		return d.Write(val)
    43  	})
    44  
    45  	d.AddCommand("RawWrite", func(params map[string]interface{}) interface{} {
    46  		val, _ := strconv.Atoi(params["val"].(string))
    47  		return d.RawWrite(val)
    48  	})
    49  
    50  	return d
    51  }
    52  
    53  // Start starts driver
    54  func (a *AnalogActuatorDriver) Start() (err error) { return }
    55  
    56  // Halt is for halt
    57  func (a *AnalogActuatorDriver) Halt() (err error) { return }
    58  
    59  // Name returns the drivers name
    60  func (a *AnalogActuatorDriver) Name() string { return a.name }
    61  
    62  // SetName sets the drivers name
    63  func (a *AnalogActuatorDriver) SetName(n string) { a.name = n }
    64  
    65  // Pin returns the drivers pin
    66  func (a *AnalogActuatorDriver) Pin() string { return a.pin }
    67  
    68  // Connection returns the drivers Connection
    69  func (a *AnalogActuatorDriver) Connection() gobot.Connection { return a.connection.(gobot.Connection) }
    70  
    71  // RawWrite write the given raw value to the actuator
    72  func (a *AnalogActuatorDriver) RawWrite(val int) (err error) {
    73  	a.lastRawValue = val
    74  	return a.connection.AnalogWrite(a.Pin(), val)
    75  }
    76  
    77  // SetScaler substitute the default 1:1 return value function by a new scaling function
    78  func (a *AnalogActuatorDriver) SetScaler(scaler func(float64) int) {
    79  	a.scale = scaler
    80  }
    81  
    82  // Write writes the given value to the actuator
    83  func (a *AnalogActuatorDriver) Write(val float64) (err error) {
    84  	a.lastValue = val
    85  	rawValue := a.scale(val)
    86  	return a.RawWrite(rawValue)
    87  }
    88  
    89  // RawValue returns the last written raw value
    90  func (a *AnalogActuatorDriver) RawValue() (val int) {
    91  	return a.lastRawValue
    92  }
    93  
    94  // Value returns the last written value
    95  func (a *AnalogActuatorDriver) Value() (val float64) {
    96  	return a.lastValue
    97  }
    98  
    99  func AnalogActuatorLinearScaler(fromMin, fromMax float64, toMin, toMax int) func(input float64) (value int) {
   100  	m := float64(toMax-toMin) / (fromMax - fromMin)
   101  	n := float64(toMin) - m*fromMin
   102  	return func(input float64) (value int) {
   103  		if input <= fromMin {
   104  			return toMin
   105  		}
   106  		if input >= fromMax {
   107  			return toMax
   108  		}
   109  		return int(input*m + n)
   110  	}
   111  }