Merge pull request hybridgroup#448 from ulisesflynn/gopigo3

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 +1,23 @@
+# 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:
+
+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/spi.go

@@ -0,0 +1,96 @@
+package spi
+
+import (
+	xspi "golang.org/x/exp/io/spi"
+	"time"
+)
+
+const (
+	// BusNotInitialized is the initial value for a bus
+	BusNotInitialized = -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
+}
+
+// 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 bus.
+	// Bus numbering starts at index 0, the range of valid buses is
+	// platform specific.
+	GetSpiConnection(busNum, 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
+}
+
+// NewConnection creates and returns a new connection to a specific
+// spi device on a bus and address
+func NewConnection(bus SPIDevice) (connection *SpiConnection) {
+	return &SpiConnection{bus: bus}
+}
+
+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)
+}

drivers/spi/spi_config.go

@@ -0,0 +1,41 @@
+package spi
+
+type spiConfig struct {
+	bus 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
+}
+
+// NewConfig returns a new SPI Config.
+func NewConfig() Config {
+	return &spiConfig{bus: BusNotInitialized}
+}
+
+// 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)
+	}
+}

examples/gopigo3.go

@@ -0,0 +1,42 @@
+// +build example
+//
+// Do not build by default.
+
+package main
+
+import (
+	"fmt"
+	"time"
+
+	"gobot.io/x/gobot"
+	g "gobot.io/x/gobot/platforms/gopigo3"
+	"gobot.io/x/gobot/platforms/raspi"
+)
+
+func main() {
+	raspiAdaptor := raspi.NewAdaptor()
+	gopigo3 := g.NewGoPiGo3Driver(raspiAdaptor)
+
+	work := func() {
+		on := uint8(0xFF)
+		gobot.Every(1000*time.Millisecond, func() {
+			err := gopigo3.SetLED(g.LED_EYE_RIGHT, 0x00, 0x00, on)
+			if err != nil {
+				fmt.Println(err)
+			}
+			err = gopigo3.SetLED(g.LED_EYE_LEFT, ^on, 0x00, 0x00)
+			if err != nil {
+				fmt.Println(err)
+			}
+			on = ^on
+		})
+	}
+
+	robot := gobot.NewRobot("gopigo3",
+		[]gobot.Connection{raspiAdaptor},
+		[]gobot.Device{gopigo3},
+		work,
+	)
+
+	robot.Start()
+}

examples/raspi_ssd1306.go

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

platforms/gopigo3/README.md

@@ -0,0 +1,53 @@
+# GoPiGo3
+
+The GoPiGo3 is a robotics controller by Dexter Industries that is compatible with the Raspberry Pi.
+
+## How to Install
+
+```
+go get -d -u gobot.io/x/gobot/...
+```
+
+## How to Use
+This example will blink the left and right leds red/blue.
+
+```go
+package main
+
+import (
+	"fmt"
+	"time"
+
+	"gobot.io/x/gobot"
+	g "gobot.io/x/gobot/platforms/gopigo3"
+	"gobot.io/x/gobot/platforms/raspi"
+)
+
+func main() {
+	raspiAdaptor := raspi.NewAdaptor()
+	gopigo3 := g.NewGoPiGo3Driver(raspiAdaptor)
+
+	work := func() {
+		on := uint8(0xFF)
+		gobot.Every(1000*time.Millisecond, func() {
+			err := gopigo3.SetLED(g.LED_EYE_RIGHT, 0x00, 0x00, on)
+			if err != nil {
+				fmt.Println(err)
+			}
+			err = gopigo3.SetLED(g.LED_EYE_LEFT, ^on, 0x00, 0x00)
+			if err != nil {
+				fmt.Println(err)
+			}
+			on = ^on
+		})
+	}
+
+	robot := gobot.NewRobot("gopigo3",
+		[]gobot.Connection{raspiAdaptor},
+		[]gobot.Device{gopigo3},
+		work,
+	)
+
+	robot.Start()
+}
+```