First cut of the GoPiGo3 driver, lacking grove peripherals.

Makefile

@@ -57,4 +57,5 @@ deps:
 		go.bug.st/serial.v1 \
 		github.com/veandco/go-sdl2/sdl \
 		golang.org/x/net/websocket \
+		golang.org/x/exp/io/spi \
 		golang.org/x/sys/unix

drivers/spi/README.MD

@@ -0,0 +1,25 @@
+# SPI
+
+This package provides drivers for [spi](https://en.wikipedia.org/wiki/Serial_Peripheral_Interface_Bus) devices. It must be used along with the [raspberry pi](https://gobot.io/documentation/platforms/raspi) adaptor that supports the needed interfaces for spi devices. This uses the experimental [spi package](https://github.com/golang/exp/tree/master/io/spi) which only works on linux systems.
+
+## Getting Started
+
+## Installing
+```
+go get -d -u gobot.io/x/gobot/...
+```
+
+## Hardware Support
+Gobot has a extensible system for connecting to hardware devices. The following spi devices are currently supported:
+
+- GoPiGo3 robotics board (built for Rapsberry Pi, but in theory it could be used in another platform)
+
+More drivers are coming soon...
+
+## Using A Different Bus or Address
+
+You can set a different SPI address or SPI bus than the default when initializing your SPI drivers by using optional parameters. Here is an example:
+
+```go
+blinkm := spi.NewGoPiGo3DriverDriver(e, spi.WithBus(0), spi.WithAddress(0x10), spi.With)
+```

drivers/spi/doc.go

@@ -0,0 +1,9 @@
+/*
+Package spi provides Gobot drivers for spi devices.
+Uses "golang.org/x/exp/io/spi" for spi
+Installing:
+	go get -d -u gobot.io/x/gobot
+For further information refer to spi README:
+https://github.com/hybridgroup/gobot/blob/master/drivers/spi/README.md
+*/
+package spi // import "gobot.io/x/gobot/drivers/spi"

drivers/spi/gopigo3_driver.go

@@ -0,0 +1,410 @@
+// based on https://github.com/DexterInd/GoPiGo3/blob/master/Software/Python/gopigo3.py
+// you will need to run the following if using a stock raspbian image before this library will work:
+// https://www.dexterindustries.com/GoPiGo/get-started-with-the-gopigo3-raspberry-pi-robot/3-program-your-raspberry-pi-robot/python-programming-language/
+package spi
+
+import (
+	"gobot.io/x/gobot"
+
+	"fmt"
+	"math"
+)
+
+// spi address for gopigo3
+const goPiGo3Address = 0x08
+
+// register addresses for gopigo3
+const (
+	NONE byte = iota
+	GET_MANUFACTURER
+	GET_NAME
+	GET_HARDWARE_VERSION
+	GET_FIRMWARE_VERSION
+	GET_ID
+	SET_LED
+	GET_VOLTAGE_5V
+	GET_VOLTAGE_VCC
+	SET_SERVO
+	SET_MOTOR_PWM
+	SET_MOTOR_POSITION
+	SET_MOTOR_POSITION_KP
+	SET_MOTOR_POSITION_KD
+	SET_MOTOR_DPS
+	SET_MOTOR_LIMITS
+	OFFSET_MOTOR_ENCODER
+	GET_MOTOR_ENCODER_LEFT
+	GET_MOTOR_ENCODER_RIGHT
+	GET_MOTOR_STATUS_LEFT
+	GET_MOTOR_STATUS_RIGHT
+	SET_GROVE_TYPE
+	SET_GROVE_MODE
+	SET_GROVE_STATE
+	SET_GROVE_PWM_DUTY
+	SET_GROVE_PWM_FREQUENCY
+	GET_GROVE_VALUE_1
+	GET_GROVE_VALUE_2
+	GET_GROVE_STATE_1_1
+	GET_GROVE_STATE_1_2
+	GET_GROVE_STATE_2_1
+	GET_GROVE_STATE_2_2
+	GET_GROVE_VOLTAGE_1_1
+	GET_GROVE_VOLTAGE_1_2
+	GET_GROVE_VOLTAGE_2_1
+	GET_GROVE_VOLTAGE_2_2
+	GET_GROVE_ANALOG_1_1
+	GET_GROVE_ANALOG_1_2
+	GET_GROVE_ANALOG_2_1
+	GET_GROVE_ANALOG_2_2
+	START_GROVE_I2C_1
+	START_GROVE_I2C_2
+)
+
+const (
+	WHEEL_BASE_WIDTH             = 117                                                       // distance (mm) from left wheel to right wheel. This works with the initial GPG3 prototype. Will need to be adjusted.
+	WHEEL_DIAMETER               = 66.5                                                      // wheel diameter (mm)
+	WHEEL_BASE_CIRCUMFERENCE     = WHEEL_BASE_WIDTH * math.Pi                                // circumference of the circle the wheels will trace while turning (mm)
+	WHEEL_CIRCUMFERENCE          = WHEEL_DIAMETER * math.Pi                                  // circumference of the wheels (mm)
+	MOTOR_GEAR_RATIO             = 120                                                       // motor gear ratio
+	ENCODER_TICKS_PER_ROTATION   = 6                                                         // encoder ticks per motor rotation (number of magnet positions)
+	MOTOR_TICKS_PER_DEGREE       = ((MOTOR_GEAR_RATIO * ENCODER_TICKS_PER_ROTATION) / 360.0) // encoder ticks per output shaft rotation degree
+	GROVE_I2C_LENGTH_LIMIT       = 16
+	MOTOR_FLOAT                  = -128
+	GROVE_INPUT_DIGITAL          = 0
+	GROVE_OUTPUT_DIGITAL         = 1
+	GROVE_INPUT_DIGITAL_PULLUP   = 2
+	GROVE_INPUT_DIGITAL_PULLDOWN = 3
+	GROVE_INPUT_ANALOG           = 4
+	GROVE_OUTPUT_PWM             = 5
+	GROVE_INPUT_ANALOG_PULLUP    = 6
+	GROVE_INPUT_ANALOG_PULLDOWN  = 7
+	GROVE_LOW                    = 0
+	GROVE_HIGH                   = 1
+)
+
+// Servo contains the address for the 2 servo ports.
+type Servo byte
+
+const (
+	SERVO_1 = 0x01
+	SERVO_2 = 0x02
+)
+
+// Motor contains the address for the left and right motors.
+type Motor byte
+
+const (
+	MOTOR_LEFT  Motor = 0x01
+	MOTOR_RIGHT Motor = 0x02
+)
+
+// Led contains the addresses for all leds on the board.
+type Led byte
+
+const (
+	LED_EYE_RIGHT     Led = 0x01
+	LED_EYE_LEFT      Led = 0x02
+	LED_BLINKER_LEFT  Led = 0x04
+	LED_BLINKER_RIGHT Led = 0x08
+	LED_WIFI          Led = 0x80
+)
+
+// Grove contains the addresses for the optional grove devices.
+type Grove byte
+
+const (
+	GROVE_1_1 = 0x01
+	GROVE_1_2 = 0x02
+	GROVE_2_1 = 0x04
+	GROVE_2_2 = 0x08
+	GROVE_1   = GROVE_1_1 + GROVE_1_2
+	GROVE_2   = GROVE_2_1 + GROVE_2_2
+)
+
+// GroveType represents the type of a grove device.
+type GroveType int
+
+const (
+	CUSTOM GroveType = iota
+	IR_DI_REMOTE
+	IR_EV3_REMOTE
+	US
+	I2C
+)
+
+// GroveState contains the state of a grove device.
+type GroveState int
+
+const (
+	VALID_DATA GroveState = iota
+	NOT_CONFIGURED
+	CONFIGURING
+	NO_DATA
+	I2C_ERROR
+)
+
+// GoPiGo3Driver is a Gobot Driver for the GoPiGo3 board.
+type GoPiGo3Driver struct {
+	name       string
+	connector  Connector
+	connection Connection
+	Config
+	sCon *SpiConnection
+}
+
+// NewGoPiGo3Driver creates a new Gobot Driver for the GoPiGo3 board.
+//
+// Params:
+//		conn Connector - the Adaptor to use with this Driver
+//
+// Optional params:
+//		spi.WithBus(int):	bus to use with this driver
+//		spi.WithAddress(int):	address to use with this driver
+//
+func NewGoPiGo3Driver(conn Connector, options ...func(Config)) *GoPiGo3Driver {
+	g := &GoPiGo3Driver{
+		name:      gobot.DefaultName("GoPiGo3"),
+		connector: conn,
+		Config:    NewConfig(),
+	}
+	for _, option := range options {
+		option(g)
+	}
+	return g
+}
+
+func (g *GoPiGo3Driver) initialization() (err error) {
+	bus := g.GetBusOrDefault(g.connector.GetSpiDefaultBus())
+	address := g.GetAddressOrDefault(goPiGo3Address)
+	mode := g.connector.GetSpiDefaultMode()
+	maxSpeed := g.connector.GetSpiDefaultMaxSpeed()
+	g.connection, err = g.connector.GetSpiConnection(bus, address, mode, maxSpeed)
+	g.sCon = g.connection.(*SpiConnection)
+	return err
+}
+
+// Name returns the name of the device.
+func (g *GoPiGo3Driver) Name() string { return g.name }
+
+// SetName sets the name of the device.
+func (g *GoPiGo3Driver) SetName(n string) { g.name = n }
+
+// Connection returns the Connection of the device.
+func (g *GoPiGo3Driver) Connection() gobot.Connection { return g.connector.(gobot.Connection) }
+
+// Halt stops the driver.
+func (g *GoPiGo3Driver) Halt() (err error) { return }
+
+// Start initializes the GoPiGo3
+func (g *GoPiGo3Driver) Start() (err error) {
+	return g.initialization()
+}
+
+// GetManufacturerName returns the manufacturer from the firmware.
+func (g *GoPiGo3Driver) GetManufacturerName() (mName string, err error) {
+	// read 24 bytes to get manufacturer name
+	response, err := g.sCon.ReadBytes(goPiGo3Address, GET_MANUFACTURER, 24)
+	if err != nil {
+		return mName, err
+	}
+	if response[3] == 0xA5 {
+		mf := response[4:23]
+		return fmt.Sprintf("%s", string(mf)), nil
+	}
+	return mName, nil
+}
+
+// GetBoardName returns the board name from the firmware.
+func (g *GoPiGo3Driver) GetBoardName() (bName string, err error) {
+	// read 24 bytes to get board name
+	response, err := g.sCon.ReadBytes(goPiGo3Address, GET_NAME, 24)
+	if err != nil {
+		return bName, err
+	}
+	if response[3] == 0xA5 {
+		mf := response[4:23]
+		return fmt.Sprintf("%s", string(mf)), nil
+	}
+	return bName, nil
+}
+
+// GetHardwareVersion returns the hardware version from the firmware.
+func (g *GoPiGo3Driver) GetHardwareVersion() (hVer string, err error) {
+	response, err := g.sCon.ReadUint32(goPiGo3Address, GET_HARDWARE_VERSION)
+	if err != nil {
+		return hVer, err
+	}
+	major := response / 1000000
+	minor := response / 1000 % 1000
+	patch := response % 1000
+	return fmt.Sprintf("%d.%d.%d", major, minor, patch), nil
+}
+
+// GetFirmwareVersion returns the current firmware version.
+func (g *GoPiGo3Driver) GetFirmwareVersion() (fVer string, err error) {
+	response, err := g.sCon.ReadUint32(goPiGo3Address, GET_FIRMWARE_VERSION)
+	if err != nil {
+		return fVer, err
+	}
+	major := response / 1000000
+	minor := response / 1000 % 1000
+	patch := response % 1000
+	return fmt.Sprintf("%d.%d.%d", major, minor, patch), nil
+}
+
+// GetSerialNumber returns the 128-bit hardware serial number of the board.
+func (g *GoPiGo3Driver) GetSerialNumber() (sNum string, err error) {
+	// read 20 bytes to get the serial number
+	response, err := g.sCon.ReadBytes(goPiGo3Address, GET_ID, 20)
+	if err != nil {
+		return sNum, err
+	}
+	if response[3] == 0xA5 {
+		return fmt.Sprintf("%02X%02X%02X%02X%02X%02X%02X%02X%02X%02X%02X%02X%02X%02X%02X%02X", response[4], response[5], response[6], response[7], response[8], response[9], response[10], response[11], response[12], response[13], response[14], response[15], response[16], response[17], response[18], response[19]), nil
+
+	}
+	return sNum, nil
+}
+
+// Get5vVoltage returns the current voltage on the 5v line.
+func (g *GoPiGo3Driver) Get5vVoltage() (voltage float32, err error) {
+	val, err := g.sCon.ReadUint16(goPiGo3Address, GET_VOLTAGE_5V)
+	return (float32(val) / 1000.0), err
+}
+
+// GetBatteryVoltage gets the battery voltage from the main battery pack (7v-12v).
+func (g *GoPiGo3Driver) GetBatteryVoltage() (voltage float32, err error) {
+	val, err := g.sCon.ReadUint16(goPiGo3Address, GET_VOLTAGE_VCC)
+	return (float32(val) / 1000.0), err
+}
+
+// SetLED sets rgb values from 0 to 255.
+func (g *GoPiGo3Driver) SetLED(led Led, red, green, blue uint8) error {
+	return g.sCon.WriteBytes([]byte{
+		goPiGo3Address,
+		SET_LED,
+		byte(led),
+		byte(red),
+		byte(green),
+		byte(blue),
+	})
+}
+
+// SetServo sets a servo's position in microseconds (0-16666).
+func (g *GoPiGo3Driver) SetServo(servo Servo, us uint16) error {
+	return g.sCon.WriteBytes([]byte{
+		goPiGo3Address,
+		SET_SERVO,
+		byte(servo),
+		byte(us),
+	})
+}
+
+// SetMotorPower from -128 to 127.
+func (g *GoPiGo3Driver) SetMotorPower(motor Motor, power int8) error {
+	return g.sCon.WriteBytes([]byte{
+		goPiGo3Address,
+		SET_MOTOR_PWM,
+		byte(motor),
+		byte(power),
+	})
+}
+
+// SetMotorPosition sets the motor's position in degrees.
+func (g *GoPiGo3Driver) SetMotorPosition(motor Motor, position float64) error {
+	positionRaw := math.Float64bits(position * MOTOR_TICKS_PER_DEGREE)
+	return g.sCon.WriteBytes([]byte{
+		goPiGo3Address,
+		SET_MOTOR_POSITION,
+		byte(motor),
+		byte((positionRaw >> 24) & 0xFF),
+		byte((positionRaw >> 16) & 0xFF),
+		byte((positionRaw >> 8) & 0xFF),
+		byte(positionRaw & 0xFF),
+	})
+}
+
+// SetMotorDps sets the motor target speed in degrees per second.
+func (g *GoPiGo3Driver) SetMotorDps(motor Motor, dps float64) error {
+	dpsUint := math.Float64bits(dps * MOTOR_TICKS_PER_DEGREE)
+	return g.sCon.WriteBytes([]byte{
+		goPiGo3Address,
+		SET_MOTOR_DPS,
+		byte(motor),
+		byte((dpsUint >> 8) & 0xFF),
+		byte(dpsUint & 0xFF),
+	})
+}
+
+// SetMotorLimits sets the speed limits for a motor.
+func (g *GoPiGo3Driver) SetMotorLimits(motor Motor, power int8, dps float64) error {
+	dpsUint := math.Float64bits(dps * MOTOR_TICKS_PER_DEGREE)
+	return g.sCon.WriteBytes([]byte{
+		goPiGo3Address,
+		SET_MOTOR_LIMITS,
+		byte(motor),
+		byte(power),
+		byte((dpsUint >> 8) & 0xFF),
+		byte(dpsUint & 0xFF),
+	})
+}
+
+// GetMotorStatus returns the status for the given motor.
+func (g *GoPiGo3Driver) GetMotorStatus(motor Motor) (flags uint8, power uint16, encoder, dps float64, err error) {
+	message := GET_MOTOR_STATUS_RIGHT
+	if motor == MOTOR_LEFT {
+		message = GET_MOTOR_STATUS_LEFT
+	}
+	response, err := g.sCon.ReadBytes(goPiGo3Address, message, 12)
+	if err != nil {
+		return flags, power, encoder, dps, err
+	}
+	if response[3] == 0xA5 {
+		flags = uint8(response[4])
+		power = uint16(response[5])
+		if power&0x80 == 0x80 {
+			power = power - 0x100
+		}
+		enc := uint64(response[6]<<24 | response[7]<<16 | response[8]<<8 | response[9])
+		if enc&0x80000000 == 0x80000000 {
+			encoder = float64(enc - 0x100000000)
+		}
+		d := uint64(response[10]<<8 | response[11])
+		if d&0x8000 == 0x8000 {
+			dps = float64(d - 0x10000)
+		}
+		return flags, power, encoder / MOTOR_TICKS_PER_DEGREE, dps / MOTOR_TICKS_PER_DEGREE, nil
+	}
+	return flags, power, encoder, dps, nil
+}
+
+// GetMotorEncoder reads a motor's encoder in degrees.
+func (g *GoPiGo3Driver) GetMotorEncoder(motor Motor) (encoder float64, err error) {
+	message := GET_MOTOR_ENCODER_RIGHT
+	if motor == MOTOR_LEFT {
+		message = GET_MOTOR_ENCODER_LEFT
+	}
+	response, err := g.sCon.ReadUint32(goPiGo3Address, message)
+	if err != nil {
+		return encoder, err
+	}
+	if response&0x80000000 == 0x80000000 {
+		encoder = float64(encoder - 0x100000000)
+	}
+	return encoder, nil
+}
+
+// OffsetMotorEncoder offsets a motor's encoder for calibration purposes.
+func (g *GoPiGo3Driver) OffsetMotorEncoder(motor Motor, offset float64) error {
+	offsetUint := math.Float64bits(offset * MOTOR_TICKS_PER_DEGREE)
+	return g.sCon.WriteBytes([]byte{
+		goPiGo3Address,
+		OFFSET_MOTOR_ENCODER,
+		byte(motor),
+		byte((offsetUint >> 24) & 0xFF),
+		byte((offsetUint >> 16) & 0xFF),
+		byte((offsetUint >> 8) & 0xFF),
+		byte(offsetUint & 0xFF),
+	})
+}
+
+//TODO: add grove functions

drivers/spi/spi.go

@@ -0,0 +1,141 @@
+package spi
+
+import (
+	xspi "golang.org/x/exp/io/spi"
+	"time"
+)
+
+const (
+	// BusNotInitialized is the initial value for a bus
+	BusNotInitialized = -1
+
+	// AddressNotInitialized is the initial value for an address
+	AddressNotInitialized = -1
+)
+
+type SPIOperations interface {
+	Close() error
+	SetBitOrder(o xspi.Order) error
+	SetBitsPerWord(bits int) error
+	SetCSChange(leaveEnabled bool) error
+	SetDelay(t time.Duration) error
+	SetMaxSpeed(speed int) error
+	SetMode(mode xspi.Mode) error
+	Tx(w, r []byte) error
+}
+
+// SPIDevice is the interface to a specific spi bus
+type SPIDevice interface {
+	SPIOperations
+	//	SetAddress(int) error
+}
+
+// Connector lets Adaptors provide the interface for Drivers
+// to get access to the SPI buses on platforms that support SPI.
+type Connector interface {
+	// GetConnection returns a connection to device at the specified address
+	// and bus. Bus numbering starts at index 0, the range of valid buses is
+	// platform specific.
+	GetSpiConnection(busNum, address, mode int, maxSpeed int64) (device Connection, err error)
+
+	// GetDefaultBus returns the default SPI bus index
+	GetSpiDefaultBus() int
+
+	// GetDefaultMode returns the default SPI mode (0/1/2/3)
+	GetSpiDefaultMode() int
+
+	// GetSpiDefaultMaxSpeed returns the max SPI speed
+	GetSpiDefaultMaxSpeed() int64
+}
+
+// Connection is a connection to an SPI device with a specified address
+// on a specific bus. Used as an alternative to the SPI interface.
+// Implements SPIOperations to talk to the device, wrapping the
+// calls in SetAddress to always target the specified device.
+// Provided by an Adaptor by implementing the SPIConnector interface.
+type Connection SPIOperations
+
+type SpiConnection struct {
+	bus      SPIDevice
+	mode     int
+	maxSpeed int64
+	address  int
+}
+
+// NewConnection creates and returns a new connection to a specific
+// spi device on a bus and address
+func NewConnection(bus SPIDevice, address int) (connection *SpiConnection) {
+	return &SpiConnection{bus: bus, address: address}
+}
+
+func (c *SpiConnection) Close() error {
+	return c.bus.Close()
+}
+
+func (c *SpiConnection) SetBitOrder(o xspi.Order) error {
+	return c.bus.SetBitOrder(o)
+}
+
+func (c *SpiConnection) SetBitsPerWord(bits int) error {
+	return c.bus.SetBitsPerWord(bits)
+}
+
+func (c *SpiConnection) SetCSChange(leaveEnabled bool) error {
+	return c.bus.SetCSChange(leaveEnabled)
+}
+
+func (c *SpiConnection) SetDelay(t time.Duration) error {
+	return c.bus.SetDelay(t)
+}
+
+func (c *SpiConnection) SetMaxSpeed(speed int) error {
+	return c.bus.SetMaxSpeed(speed)
+}
+
+func (c *SpiConnection) SetMode(mode xspi.Mode) error {
+	return c.bus.SetMode(mode)
+}
+
+func (c *SpiConnection) Tx(w, r []byte) error {
+	return c.bus.Tx(w, r)
+}
+
+func (c *SpiConnection) ReadBytes(address byte, msg byte, numBytes int) (val []byte, err error) {
+	w := make([]byte, numBytes)
+	w[0] = address
+	w[1] = msg
+	r := make([]byte, len(w))
+	err = c.Tx(w, r)
+	if err != nil {
+		return val, err
+	}
+	return r, nil
+}
+
+func (c *SpiConnection) ReadUint8(address, msg byte) (val uint8, err error) {
+	r, err := c.ReadBytes(address, msg, 8)
+	if err != nil {
+		return val, err
+	}
+	return uint8(r[4]) << 8, nil
+}
+
+func (c *SpiConnection) ReadUint16(address, msg byte) (val uint16, err error) {
+	r, err := c.ReadBytes(address, msg, 8)
+	if err != nil {
+		return val, err
+	}
+	return uint16(r[4])<<8 | uint16(r[5]), nil
+}
+
+func (c *SpiConnection) ReadUint32(address, msg byte) (val uint32, err error) {
+	r, err := c.ReadBytes(address, msg, 8)
+	if err != nil {
+		return val, err
+	}
+	return uint32(r[4])<<24 | uint32(r[5])<<16 | uint32(r[6])<<8 | uint32(r[7]), nil
+}
+
+func (c *SpiConnection) WriteBytes(w []byte) (err error) {
+	return c.Tx(w, nil)
+}

drivers/spi/spi_config.go

@@ -0,0 +1,70 @@
+package spi
+
+type spiConfig struct {
+	bus     int
+	address int
+}
+
+// Config is the interface which describes how a Driver can specify
+// optional SPI params such as which SPI bus it wants to use.
+type Config interface {
+	// WithBus sets which bus to use
+	WithBus(bus int)
+
+	// GetBusOrDefault gets which bus to use
+	GetBusOrDefault(def int) int
+
+	// WithAddress sets which address to use
+	WithAddress(address int)
+
+	// GetAddressOrDefault gets which address to use
+	GetAddressOrDefault(def int) int
+}
+
+// NewConfig returns a new SPI Config.
+func NewConfig() Config {
+	return &spiConfig{bus: BusNotInitialized, address: AddressNotInitialized}
+}
+
+// WithBus sets preferred bus to use.
+func (s *spiConfig) WithBus(bus int) {
+	s.bus = bus
+}
+
+// GetBusOrDefault returns which bus to use, either the one set using WithBus(),
+// or the default value which is passed in as the one param.
+func (s *spiConfig) GetBusOrDefault(d int) int {
+	if s.bus == BusNotInitialized {
+		return d
+	}
+	return s.bus
+}
+
+// WithBus sets which bus to use as a optional param.
+func WithBus(bus int) func(Config) {
+	return func(s Config) {
+		s.WithBus(bus)
+	}
+}
+
+// WithAddress sets which address to use.
+func (s *spiConfig) WithAddress(address int) {
+	s.address = address
+}
+
+// GetAddressOrDefault returns which address to use, either
+// the one set using WithBus(), or the default value which
+// is passed in as the param.
+func (s *spiConfig) GetAddressOrDefault(a int) int {
+	if s.address == AddressNotInitialized {
+		return a
+	}
+	return s.address
+}
+
+// WithAddress sets which address to use as a optional param.
+func WithAddress(address int) func(Config) {
+	return func(s Config) {
+		s.WithAddress(address)
+	}
+}

examples/raspi_gopigo3.go

@@ -0,0 +1,32 @@
+// +build example
+//
+// Do not build by default.
+
+package main
+
+import (
+	"time"
+
+	"gobot.io/x/gobot"
+	"gobot.io/x/gobot/drivers/spi"
+	"gobot.io/x/gobot/platforms/raspi"
+)
+
+func main() {
+	r := raspi.NewAdaptor()
+	g := spi.NewGoPiGo3Driver(r)
+	g.Start()
+	work := func() {
+		g.SetLED(spi.LED_EYE_LEFT, 255, 0, 0)
+		g.SetLED(spi.LED_EYE_RIGHT, 0, 255, 0)
+		time.Sleep(1 * time.Second)
+		g.SetLED(spi.LED_EYE_LEFT, 0, 255, 0)
+		g.SetLED(spi.LED_EYE_RIGHT, 255, 0, 0)
+	}
+	robot := gobot.NewRobot("gopigo3-bot",
+		[]gobot.Connection{r},
+		[]gobot.Device{g},
+		work,
+	)
+	robot.Start()
+}

examples/raspi_ssd1306.go

@@ -1,3 +1,7 @@
+// +build example
+//
+// Do not build by default.
+
 package main
 
 import (

platforms/raspi/raspi_adaptor.go

@@ -12,7 +12,9 @@ import (
 	multierror "github.com/hashicorp/go-multierror"
 	"gobot.io/x/gobot"
 	"gobot.io/x/gobot/drivers/i2c"
+	"gobot.io/x/gobot/drivers/spi"
 	"gobot.io/x/gobot/sysfs"
+	xspi "golang.org/x/exp/io/spi"
 )
 
 var readFile = func() ([]byte, error) {
@@ -21,13 +23,17 @@ var readFile = func() ([]byte, error) {
 
 // Adaptor is the Gobot Adaptor for the Raspberry Pi
 type Adaptor struct {
-	mutex         *sync.Mutex
-	name          string
-	revision      string
-	digitalPins   map[int]*sysfs.DigitalPin
-	pwmPins       map[int]*PWMPin
-	i2cDefaultBus int
-	i2cBuses      [2]i2c.I2cDevice
+	mutex              *sync.Mutex
+	name               string
+	revision           string
+	digitalPins        map[int]*sysfs.DigitalPin
+	pwmPins            map[int]*PWMPin
+	i2cDefaultBus      int
+	i2cBuses           [2]i2c.I2cDevice
+	spiDefaultBus      int
+	spiBuses           [2]spi.SPIDevice
+	spiDefaultMode     int
+	spiDefaultMaxSpeed int64
 }
 
 // NewAdaptor creates a Raspi Adaptor
@@ -44,6 +50,9 @@ func NewAdaptor() *Adaptor {
 			s := strings.Split(string(v), " ")
 			version, _ := strconv.ParseInt("0x"+s[len(s)-1], 0, 64)
 			r.i2cDefaultBus = 1
+			r.spiDefaultBus = 1
+			r.spiDefaultMode = 0
+			r.spiDefaultMaxSpeed = 500000
 			if version <= 3 {
 				r.revision = "1"
 				r.i2cDefaultBus = 0
@@ -106,6 +115,13 @@ func (r *Adaptor) Finalize() (err error) {
 			}
 		}
 	}
+	for _, bus := range r.spiBuses {
+		if bus != nil {
+			if e := bus.Close(); e != nil {
+				err = multierror.Append(err, e)
+			}
+		}
+	}
 	return
 }
 
@@ -190,6 +206,66 @@ func (r *Adaptor) GetDefaultBus() int {
 	return r.i2cDefaultBus
 }
 
+// GetSpiConnection returns an spi connection to a device on a specified bus.
+// Valid bus number is [0..1] which corresponds to /dev/spidev0.0 through /dev/spidev0.1.
+func (r *Adaptor) GetSpiConnection(busNum, address, mode int, maxSpeed int64) (connection spi.Connection, err error) {
+	if (busNum < 0) || (busNum > 1) {
+		return nil, fmt.Errorf("Bus number %d out of range", busNum)
+	}
+	device, err := r.getSpiBus(busNum, address, mode, maxSpeed)
+	return spi.NewConnection(device, address), err
+}
+
+func (r *Adaptor) getSpiBus(busNum, address, mode int, maxSpeed int64) (_ spi.SPIDevice, err error) {
+	r.mutex.Lock()
+	defer r.mutex.Unlock()
+
+	if r.spiBuses[busNum] == nil {
+		var spiMode xspi.Mode
+		switch mode {
+		case 0:
+			spiMode = xspi.Mode0
+		case 1:
+			spiMode = xspi.Mode1
+		case 2:
+			spiMode = xspi.Mode2
+		case 3:
+			spiMode = xspi.Mode3
+		default:
+			spiMode = xspi.Mode0
+		}
+		dev := fmt.Sprintf("/dev/spidev0.%d", busNum)
+		devfs := &xspi.Devfs{
+			Dev:      dev,
+			Mode:     spiMode,
+			MaxSpeed: maxSpeed,
+		}
+		if r.spiBuses[busNum] == nil {
+			bus, err := xspi.Open(devfs)
+			if err != nil {
+				return nil, err
+			}
+			r.spiBuses[busNum] = spi.NewConnection(bus, address)
+		}
+	}
+	return r.spiBuses[busNum], err
+}
+
+// GetSpiDefaultBus returns the default spi bus for this platform.
+func (r *Adaptor) GetSpiDefaultBus() int {
+	return r.spiDefaultBus
+}
+
+// GetSpiDefaultMode returns the default spi mode for this platform.
+func (r *Adaptor) GetSpiDefaultMode() int {
+	return r.spiDefaultMode
+}
+
+// GetDefaultMaxSpeed returns the default spi bus for this platform.
+func (r *Adaptor) GetSpiDefaultMaxSpeed() int64 {
+	return r.spiDefaultMaxSpeed
+}
+
 // PWMPin returns a raspi.PWMPin which provides the sysfs.PWMPinner interface
 func (r *Adaptor) PWMPin(pin string) (raspiPWMPin sysfs.PWMPinner, err error) {
 	i, err := r.translatePin(pin)

platforms/raspi/raspi_adaptor_test.go

@@ -8,6 +8,7 @@ import (
 	"gobot.io/x/gobot"
 	"gobot.io/x/gobot/drivers/gpio"
 	"gobot.io/x/gobot/drivers/i2c"
+	"gobot.io/x/gobot/drivers/spi"
 	"gobot.io/x/gobot/gobottest"
 	"gobot.io/x/gobot/sysfs"
 	"runtime"
@@ -24,6 +25,7 @@ var _ gpio.ServoWriter = (*Adaptor)(nil)
 var _ sysfs.DigitalPinnerProvider = (*Adaptor)(nil)
 var _ sysfs.PWMPinnerProvider = (*Adaptor)(nil)
 var _ i2c.Connector = (*Adaptor)(nil)
+var _ spi.Connector = (*Adaptor)(nil)
 
 func initTestAdaptor() *Adaptor {
 	readFile = func() ([]byte, error) {
@@ -91,6 +93,8 @@ func TestAdaptorFinalize(t *testing.T) {
 		"/dev/pi-blaster",
 		"/dev/i2c-1",
 		"/dev/i2c-0",
+		"/dev/spidev0.0",
+		"/dev/spidev0.1",
 	})
 
 	sysfs.SetFilesystem(fs)
@@ -178,6 +182,27 @@ func TestAdaptorI2c(t *testing.T) {
 	gobottest.Assert(t, a.GetDefaultBus(), 1)
 }
 
+func TestAdaptorSPI(t *testing.T) {
+	a := initTestAdaptor()
+	fs := sysfs.NewMockFilesystem([]string{
+		"/dev/spidev0.1",
+	})
+	sysfs.SetFilesystem(fs)
+	sysfs.SetSyscall(&sysfs.MockSyscall{})
+	// TODO: find a better way to test this
+	_, err := a.GetSpiConnection(1, 0xC0, 0, 500000)
+	gobottest.Assert(t, err, err)
+	gobottest.Assert(t, a.GetSpiDefaultBus(), 1)
+	gobottest.Assert(t, a.GetSpiDefaultMode(), 0)
+	gobottest.Assert(t, a.GetSpiDefaultMaxSpeed(), int64(500000))
+
+	_, err = a.GetSpiConnection(1, 0xC0, 1, 500000)
+	_, err = a.GetSpiConnection(1, 0xC0, 2, 500000)
+	_, err = a.GetSpiConnection(1, 0xC0, 3, 500000)
+	_, err = a.GetSpiConnection(1, 0xC0, 5, 500000)
+	_, err = a.GetSpiConnection(4, 0xC0, 0, 500000)
+}
+
 func TestAdaptorDigitalPinConcurrency(t *testing.T) {
 
 	oldProcs := runtime.GOMAXPROCS(0)