hybridgroup.gobot/platforms/sphero/sphero_driver.go

325 lines
8.2 KiB
Go

package sphero
import (
"bytes"
"encoding/binary"
"errors"
"time"
"github.com/hybridgroup/gobot"
)
var _ gobot.Driver = (*SpheroDriver)(nil)
type packet struct {
header []uint8
body []uint8
checksum uint8
}
// Represents a Sphero
type SpheroDriver struct {
name string
connection gobot.Connection
seq uint8
asyncResponse [][]uint8
syncResponse [][]uint8
packetChannel chan *packet
responseChannel chan []uint8
gobot.Eventer
gobot.Commander
}
type Collision struct {
// Normalized impact components (direction of the collision event):
X, Y, Z int16
// Thresholds exceeded by X (1h) and/or Y (2h) axis (bitmask):
Axis byte
// Power that cross threshold Xt + Xs:
XMagnitude, YMagnitude int16
// Sphero's speed when impact detected:
Speed uint8
// Millisecond timer
Timestamp uint32
}
// NewSpheroDriver returns a new SpheroDriver given a SpheroAdaptor and name.
//
// Adds the following API Commands:
// "Roll" - See SpheroDriver.Roll
// "Stop" - See SpheroDriver.Stop
// "GetRGB" - See SpheroDriver.GetRGB
// "SetBackLED" - See SpheroDriver.SetBackLED
// "SetHeading" - See SpheroDriver.SetHeading
// "SetStabilization" - See SpheroDriver.SetStabilization
func NewSpheroDriver(a *SpheroAdaptor, name string) *SpheroDriver {
s := &SpheroDriver{
name: name,
connection: a,
Eventer: gobot.NewEventer(),
Commander: gobot.NewCommander(),
packetChannel: make(chan *packet, 1024),
responseChannel: make(chan []uint8, 1024),
}
s.AddEvent("error")
s.AddEvent("collision")
s.AddCommand("SetRGB", func(params map[string]interface{}) interface{} {
r := uint8(params["r"].(float64))
g := uint8(params["g"].(float64))
b := uint8(params["b"].(float64))
s.SetRGB(r, g, b)
return nil
})
s.AddCommand("Roll", func(params map[string]interface{}) interface{} {
speed := uint8(params["speed"].(float64))
heading := uint16(params["heading"].(float64))
s.Roll(speed, heading)
return nil
})
s.AddCommand("Stop", func(params map[string]interface{}) interface{} {
s.Stop()
return nil
})
s.AddCommand("GetRGB", func(params map[string]interface{}) interface{} {
return s.GetRGB()
})
s.AddCommand("SetBackLED", func(params map[string]interface{}) interface{} {
level := uint8(params["level"].(float64))
s.SetBackLED(level)
return nil
})
s.AddCommand("SetHeading", func(params map[string]interface{}) interface{} {
heading := uint16(params["heading"].(float64))
s.SetHeading(heading)
return nil
})
s.AddCommand("SetStabilization", func(params map[string]interface{}) interface{} {
on := params["enable"].(bool)
s.SetStabilization(on)
return nil
})
return s
}
func (s *SpheroDriver) Name() string { return s.name }
func (s *SpheroDriver) Connection() gobot.Connection { return s.connection }
func (s *SpheroDriver) adaptor() *SpheroAdaptor {
return s.Connection().(*SpheroAdaptor)
}
// Start starts the SpheroDriver and enables Collision Detection.
// Returns true on successful start.
//
// Emits the Events:
// "collision" SpheroDriver.Collision - On Collision Detected
func (s *SpheroDriver) Start() (errs []error) {
go func() {
for {
packet := <-s.packetChannel
err := s.write(packet)
if err != nil {
gobot.Publish(s.Event("error"), err)
}
}
}()
go func() {
for {
response := <-s.responseChannel
s.syncResponse = append(s.syncResponse, response)
}
}()
go func() {
for {
header := s.readHeader()
if header != nil && len(header) != 0 {
body := s.readBody(header[4])
data := append(header, body...)
checksum := data[len(data)-1]
if checksum != calculateChecksum(data[2:len(data)-1]) {
continue
}
switch header[1] {
case 0xFE:
s.asyncResponse = append(s.asyncResponse, data)
case 0xFF:
s.responseChannel <- data
}
}
}
}()
go func() {
for {
var evt []uint8
for len(s.asyncResponse) != 0 {
evt, s.asyncResponse = s.asyncResponse[len(s.asyncResponse)-1], s.asyncResponse[:len(s.asyncResponse)-1]
if evt[2] == 0x07 {
s.handleCollisionDetected(evt)
}
}
time.Sleep(100 * time.Millisecond)
}
}()
s.configureCollisionDetection()
s.enableStopOnDisconnect()
return
}
// Halt halts the SpheroDriver and sends a SpheroDriver.Stop command to the Sphero.
// Returns true on successful halt.
func (s *SpheroDriver) Halt() (errs []error) {
gobot.Every(10*time.Millisecond, func() {
s.Stop()
})
time.Sleep(1 * time.Second)
return
}
// SetRGB sets the Sphero to the given r, g, and b values
func (s *SpheroDriver) SetRGB(r uint8, g uint8, b uint8) {
s.packetChannel <- s.craftPacket([]uint8{r, g, b, 0x01}, 0x02, 0x20)
}
// GetRGB returns the current r, g, b value of the Sphero
func (s *SpheroDriver) GetRGB() []uint8 {
buf := s.getSyncResponse(s.craftPacket([]uint8{}, 0x02, 0x22))
if len(buf) == 9 {
return []uint8{buf[5], buf[6], buf[7]}
}
return []uint8{}
}
// SetBackLED sets the Sphero Back LED to the specified brightness
func (s *SpheroDriver) SetBackLED(level uint8) {
s.packetChannel <- s.craftPacket([]uint8{level}, 0x02, 0x21)
}
// SetHeading sets the heading of the Sphero
func (s *SpheroDriver) SetHeading(heading uint16) {
s.packetChannel <- s.craftPacket([]uint8{uint8(heading >> 8), uint8(heading & 0xFF)}, 0x02, 0x01)
}
// SetStabilization enables or disables the built-in auto stabilizing features of the Sphero
func (s *SpheroDriver) SetStabilization(on bool) {
b := uint8(0x01)
if on == false {
b = 0x00
}
s.packetChannel <- s.craftPacket([]uint8{b}, 0x02, 0x02)
}
// Roll sends a roll command to the Sphero gives a speed and heading
func (s *SpheroDriver) Roll(speed uint8, heading uint16) {
s.packetChannel <- s.craftPacket([]uint8{speed, uint8(heading >> 8), uint8(heading & 0xFF), 0x01}, 0x02, 0x30)
}
// Stop sets the Sphero to a roll speed of 0
func (s *SpheroDriver) Stop() {
s.Roll(0, 0)
}
func (s *SpheroDriver) configureCollisionDetection() {
s.packetChannel <- s.craftPacket([]uint8{0x01, 0x40, 0x40, 0x50, 0x50, 0x60}, 0x02, 0x12)
}
func (s *SpheroDriver) enableStopOnDisconnect() {
s.packetChannel <- s.craftPacket([]uint8{0x00, 0x00, 0x00, 0x01}, 0x02, 0x37)
}
func (s *SpheroDriver) handleCollisionDetected(data []uint8) {
// ensure data is the right length:
if len(data) != 22 || data[4] != 17 {
return
}
var collision Collision
buffer := bytes.NewBuffer(data[5:]) // skip header
binary.Read(buffer, binary.BigEndian, &collision)
gobot.Publish(s.Event("collision"), collision)
}
func (s *SpheroDriver) getSyncResponse(packet *packet) []byte {
s.packetChannel <- packet
for i := 0; i < 500; i++ {
for key := range s.syncResponse {
if s.syncResponse[key][3] == packet.header[4] && len(s.syncResponse[key]) > 6 {
var response []byte
response, s.syncResponse = s.syncResponse[len(s.syncResponse)-1], s.syncResponse[:len(s.syncResponse)-1]
return response
}
}
time.Sleep(100 * time.Microsecond)
}
return []byte{}
}
func (s *SpheroDriver) craftPacket(body []uint8, did byte, cid byte) *packet {
packet := new(packet)
packet.body = body
dlen := len(packet.body) + 1
packet.header = []uint8{0xFF, 0xFF, did, cid, s.seq, uint8(dlen)}
packet.checksum = s.calculateChecksum(packet)
return packet
}
func (s *SpheroDriver) write(packet *packet) (err error) {
buf := append(packet.header, packet.body...)
buf = append(buf, packet.checksum)
length, err := s.adaptor().sp.Write(buf)
if err != nil {
return err
} else if length != len(buf) {
return errors.New("Not enough bytes written")
}
s.seq++
return
}
func (s *SpheroDriver) calculateChecksum(packet *packet) uint8 {
buf := append(packet.header, packet.body...)
return calculateChecksum(buf[2:])
}
func calculateChecksum(buf []byte) byte {
var calculatedChecksum uint16
for i := range buf {
calculatedChecksum += uint16(buf[i])
}
return uint8(^(calculatedChecksum % 256))
}
func (s *SpheroDriver) readHeader() []uint8 {
return s.readNextChunk(5)
}
func (s *SpheroDriver) readBody(length uint8) []uint8 {
return s.readNextChunk(int(length))
}
func (s *SpheroDriver) readNextChunk(length int) []uint8 {
read := make([]uint8, length)
bytesRead := 0
for bytesRead < length {
time.Sleep(1 * time.Millisecond)
n, err := s.adaptor().sp.Read(read[bytesRead:])
if err != nil {
return nil
}
bytesRead += n
}
return read
}