firmata_adaptor.go

//go:build !windows
// +build !windows

package firmata

import (
	"fmt"
	"io"
	"strconv"
	"time"

	"go.bug.st/serial"

	"gobot.io/x/gobot/v2"
	"gobot.io/x/gobot/v2/drivers/i2c"
	"gobot.io/x/gobot/v2/platforms/firmata/client"
)

type firmataBoard interface {
	Connect(conn io.ReadWriteCloser) error
	Disconnect() error
	Pins() []client.Pin
	AnalogWrite(pin int, value int) error
	SetPinMode(pin int, mode int) error
	ReportAnalog(pin int, state int) error
	ReportDigital(pin int, state int) error
	DigitalWrite(pin int, value int) error
	I2cRead(address int, numBytes int) error
	I2cWrite(address int, data []byte) error
	I2cConfig(delay int) error
	ServoConfig(pin int, max int, min int) error
	WriteSysex(data []byte) error
	gobot.Eventer
}

type FirmataAdaptor interface {
	Connect() error
	Finalize() error
	Name() string
	SetName(n string)
	WriteSysex(data []byte) error
	gobot.Eventer
}

// Adaptor is the Gobot Adaptor for Firmata based boards
type Adaptor struct {
	name       string
	port       string
	Board      firmataBoard
	conn       io.ReadWriteCloser
	PortOpener func(port string) (io.ReadWriteCloser, error)
	gobot.Eventer
}

// NewAdaptor returns a new Firmata Adaptor which optionally accepts:
//
//	string: port the Adaptor uses to connect to a serial port with a baude rate of 57600
//	io.ReadWriteCloser: connection the Adaptor uses to communication with the hardware
//
// If an io.ReadWriteCloser is not supplied, the Adaptor will open a connection
// to a serial port with a baude rate of 57600. If an io.ReadWriteCloser
// is supplied, then the Adaptor will use the provided io.ReadWriteCloser and use the
// string port as a label to be displayed in the log and api.
func NewAdaptor(args ...interface{}) *Adaptor {
	f := &Adaptor{
		name:  gobot.DefaultName("Firmata"),
		port:  "",
		conn:  nil,
		Board: client.New(),
		PortOpener: func(port string) (io.ReadWriteCloser, error) {
			return serial.Open(port, &serial.Mode{BaudRate: 57600})
		},
		Eventer: gobot.NewEventer(),
	}

	for _, arg := range args {
		switch a := arg.(type) {
		case string:
			f.port = a
		case io.ReadWriteCloser:
			f.conn = a
		}
	}

	return f
}

// Connect starts a connection to the board.
func (f *Adaptor) Connect() error {
	if f.conn == nil {
		sp, err := f.PortOpener(f.Port())
		if err != nil {
			return err
		}
		f.conn = sp
	}
	if err := f.Board.Connect(f.conn); err != nil {
		return err
	}

	return f.Board.On("SysexResponse", func(data interface{}) {
		f.Publish("SysexResponse", data)
	})
}

// Disconnect closes the io connection to the Board
func (f *Adaptor) Disconnect() error {
	if f.Board != nil {
		return f.Board.Disconnect()
	}
	return nil
}

// Finalize terminates the firmata connection
func (f *Adaptor) Finalize() error {
	return f.Disconnect()
}

// Port returns the Firmata Adaptors port
func (f *Adaptor) Port() string { return f.port }

// Name returns the Firmata Adaptors name
func (f *Adaptor) Name() string { return f.name }

// SetName sets the Firmata Adaptors name
func (f *Adaptor) SetName(n string) { f.name = n }

// ServoConfig sets the pulse width in microseconds for a pin attached to a servo
func (f *Adaptor) ServoConfig(pin string, min, max int) error {
	p, err := strconv.Atoi(pin)
	if err != nil {
		return err
	}

	return f.Board.ServoConfig(p, max, min)
}

// ServoWrite writes the 0-180 degree angle to the specified pin.
func (f *Adaptor) ServoWrite(pin string, angle byte) error {
	p, err := strconv.Atoi(pin)
	if err != nil {
		return err
	}

	if f.Board.Pins()[p].Mode != client.Servo {
		err = f.Board.SetPinMode(p, client.Servo)
		if err != nil {
			return err
		}
	}

	return f.Board.AnalogWrite(p, int(angle))
}

// PwmWrite writes the 0-254 value to the specified pin
func (f *Adaptor) PwmWrite(pin string, level byte) error {
	p, err := strconv.Atoi(pin)
	if err != nil {
		return err
	}

	if f.Board.Pins()[p].Mode != client.Pwm {
		err = f.Board.SetPinMode(p, client.Pwm)
		if err != nil {
			return err
		}
	}

	return f.Board.AnalogWrite(p, int(level))
}

// DigitalWrite writes a value to the pin. Acceptable values are 1 or 0.
func (f *Adaptor) DigitalWrite(pin string, level byte) error {
	p, err := strconv.Atoi(pin)
	if err != nil {
		return err
	}

	if f.Board.Pins()[p].Mode != client.Output {
		if err = f.Board.SetPinMode(p, client.Output); err != nil {
			return err
		}
	}

	return f.Board.DigitalWrite(p, int(level))
}

// DigitalRead retrieves digital value from specified pin.
// Returns -1 if the response from the board has timed out
func (f *Adaptor) DigitalRead(pin string) (int, error) {
	p, err := strconv.Atoi(pin)
	if err != nil {
		return 0, err
	}

	if f.Board.Pins()[p].Mode != client.Input {
		if err := f.Board.SetPinMode(p, client.Input); err != nil {
			return 0, err
		}
		if err := f.Board.ReportDigital(p, 1); err != nil {
			return 0, err
		}
		<-time.After(10 * time.Millisecond)
	}

	return f.Board.Pins()[p].Value, nil
}

// AnalogRead retrieves value from analog pin.
// Returns -1 if the response from the board has timed out
func (f *Adaptor) AnalogRead(pin string) (int, error) {
	p, err := strconv.Atoi(pin)
	if err != nil {
		return 0, err
	}

	p = f.digitalPin(p)

	if f.Board.Pins()[p].Mode != client.Analog {
		if err := f.Board.SetPinMode(p, client.Analog); err != nil {
			return 0, err
		}

		if err := f.Board.ReportAnalog(p, 1); err != nil {
			return 0, err
		}
		<-time.After(10 * time.Millisecond)
	}

	return f.Board.Pins()[p].Value, nil
}

func (f *Adaptor) WriteSysex(data []byte) error {
	return f.Board.WriteSysex(data)
}

// digitalPin converts pin number to digital mapping
func (f *Adaptor) digitalPin(pin int) int {
	return pin + 14
}

// GetI2cConnection returns an i2c connection to a device on a specified bus.
// Only supports bus number 0
func (f *Adaptor) GetI2cConnection(address int, bus int) (i2c.Connection, error) {
	if bus != 0 {
		return nil, fmt.Errorf("Invalid bus number %d, only 0 is supported", bus)
	}
	if err := f.Board.I2cConfig(0); err != nil {
		return nil, err
	}
	return NewFirmataI2cConnection(f, address), nil
}

// DefaultI2cBus returns the default i2c bus for this platform
func (f *Adaptor) DefaultI2cBus() int {
	return 0
}