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package gpio
import (
"gobot.io/x/gobot"
)
// MotorDriver Represents a Motor
type MotorDriver struct {
name string
connection DigitalWriter
SpeedPin string
SwitchPin string
DirectionPin string
ForwardPin string
BackwardPin string
CurrentState byte
CurrentSpeed byte
CurrentMode string
CurrentDirection string
}
// NewMotorDriver return a new MotorDriver given a DigitalWriter and pin
func NewMotorDriver(a DigitalWriter, speedPin string) *MotorDriver {
return &MotorDriver{
name: gobot.DefaultName("Motor"),
connection: a,
SpeedPin: speedPin,
CurrentState: 0,
CurrentSpeed: 0,
CurrentMode: "digital",
CurrentDirection: "forward",
}
}
// Name returns the MotorDrivers name
func (m *MotorDriver) Name() string { return m.name }
// SetName sets the MotorDrivers name
func (m *MotorDriver) SetName(n string) { m.name = n }
// Connection returns the MotorDrivers Connection
func (m *MotorDriver) Connection() gobot.Connection { return m.connection.(gobot.Connection) }
// Start implements the Driver interface
func (m *MotorDriver) Start() (err error) { return }
// Halt implements the Driver interface
func (m *MotorDriver) Halt() (err error) { return }
// Off turns the motor off or sets the motor to a 0 speed
func (m *MotorDriver) Off() (err error) {
if m.isDigital() {
err = m.changeState(0)
} else {
err = m.Speed(0)
}
return
}
// On turns the motor on or sets the motor to a maximum speed
func (m *MotorDriver) On() (err error) {
if m.isDigital() {
err = m.changeState(1)
} else {
if m.CurrentSpeed == 0 {
m.CurrentSpeed = 255
}
err = m.Speed(m.CurrentSpeed)
}
return
}
// Min sets the motor to the minimum speed
func (m *MotorDriver) Min() (err error) {
return m.Off()
}
// Max sets the motor to the maximum speed
func (m *MotorDriver) Max() (err error) {
return m.Speed(255)
}
// IsOn returns true if the motor is on
func (m *MotorDriver) IsOn() bool {
if m.isDigital() {
return m.CurrentState == 1
}
return m.CurrentSpeed > 0
}
// IsOff returns true if the motor is off
func (m *MotorDriver) IsOff() bool {
return !m.IsOn()
}
// Toggle sets the motor to the opposite of it's current state
func (m *MotorDriver) Toggle() (err error) {
if m.IsOn() {
err = m.Off()
} else {
err = m.On()
}
return
}
// Speed sets the speed of the motor
func (m *MotorDriver) Speed(value byte) (err error) {
if writer, ok := m.connection.(PwmWriter); ok {
m.CurrentMode = "analog"
m.CurrentSpeed = value
return writer.PwmWrite(m.SpeedPin, value)
}
return ErrPwmWriteUnsupported
}
// Forward sets the forward pin to the specified speed
func (m *MotorDriver) Forward(speed byte) (err error) {
err = m.Direction("forward")
if err != nil {
return
}
err = m.Speed(speed)
if err != nil {
return
}
return
}
// Backward sets the backward pin to the specified speed
func (m *MotorDriver) Backward(speed byte) (err error) {
err = m.Direction("backward")
if err != nil {
return
}
err = m.Speed(speed)
if err != nil {
return
}
return
}
// Direction sets the direction pin to the specified speed
func (m *MotorDriver) Direction(direction string) (err error) {
m.CurrentDirection = direction
if m.DirectionPin != "" {
var level byte
if direction == "forward" {
level = 1
} else {
level = 0
}
err = m.connection.DigitalWrite(m.DirectionPin, level)
} else {
var forwardLevel, backwardLevel byte
switch direction {
case "forward":
forwardLevel = 1
backwardLevel = 0
case "backward":
forwardLevel = 0
backwardLevel = 1
case "none":
forwardLevel = 0
backwardLevel = 0
}
err = m.connection.DigitalWrite(m.ForwardPin, forwardLevel)
if err != nil {
return
}
err = m.connection.DigitalWrite(m.BackwardPin, backwardLevel)
if err != nil {
return
}
}
return
}
func (m *MotorDriver) isDigital() bool {
return m.CurrentMode == "digital"
}
func (m *MotorDriver) changeState(state byte) (err error) {
m.CurrentState = state
if state == 1 {
m.CurrentSpeed = 255
} else {
m.CurrentSpeed = 0
}
if m.ForwardPin != "" {
if state == 1 {
err = m.Direction(m.CurrentDirection)
if err != nil {
return
}
if m.SpeedPin != "" {
err = m.Speed(m.CurrentSpeed)
if err != nil {
return
}
}
} else {
err = m.Direction("none")
}
} else {
err = m.connection.DigitalWrite(m.SpeedPin, state)
}
return
}
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