Add MMA7660Driver

examples/firmata_mma7660.go

@@ -0,0 +1,38 @@
+package main
+
+import (
+	"fmt"
+	"time"
+
+	"github.com/hybridgroup/gobot"
+	"github.com/hybridgroup/gobot/platforms/firmata"
+	"github.com/hybridgroup/gobot/platforms/i2c"
+)
+
+func main() {
+	gbot := gobot.NewGobot()
+
+	firmataAdaptor := firmata.NewFirmataAdaptor("firmata", "/dev/ttyACM0")
+	mma7660 := i2c.NewMMA7660Driver(firmataAdaptor, "mma7660")
+
+	work := func() {
+		gobot.Every(500*time.Millisecond, func() {
+			if x, y, z, err := mma7660.XYZ(); err == nil {
+				fmt.Println(x, y, z)
+				fmt.Println(mma7660.Acceleration(x, y, z))
+			} else {
+				fmt.Println(err)
+			}
+		})
+	}
+
+	robot := gobot.NewRobot("mma76602Bot",
+		[]gobot.Connection{firmataAdaptor},
+		[]gobot.Device{mma7660},
+		work,
+	)
+
+	gbot.AddRobot(robot)
+
+	gbot.Start()
+}

platforms/i2c/i2c.go

@@ -9,6 +9,7 @@ import (
 var (
 	ErrEncryptedBytes = errors.New("Encrypted bytes")
 	ErrNotEnoughBytes = errors.New("Not enough bytes read")
+	ErrNotReady       = errors.New("Device is not ready")
 )
 
 const (

platforms/i2c/mma7660_driver.go

@@ -0,0 +1,102 @@
+package i2c
+
+import "github.com/hybridgroup/gobot"
+
+var _ gobot.Driver = (*MMA7660Driver)(nil)
+
+const mma7660Address = 0x4c
+
+const (
+	MMA7660_X              = 0x00
+	MMA7660_Y              = 0x01
+	MMA7660_Z              = 0x02
+	MMA7660_TILT           = 0x03
+	MMA7660_SRST           = 0x04
+	MMA7660_SPCNT          = 0x05
+	MMA7660_INTSU          = 0x06
+	MMA7660_MODE           = 0x07
+	MMA7660_STAND_BY       = 0x00
+	MMA7660_ACTIVE         = 0x01
+	MMA7660_SR             = 0x08
+	MMA7660_AUTO_SLEEP_120 = 0x00
+	MMA7660_AUTO_SLEEP_64  = 0x01
+	MMA7660_AUTO_SLEEP_32  = 0x02
+	MMA7660_AUTO_SLEEP_16  = 0x03
+	MMA7660_AUTO_SLEEP_8   = 0x04
+	MMA7660_AUTO_SLEEP_4   = 0x05
+	MMA7660_AUTO_SLEEP_2   = 0x06
+	MMA7660_AUTO_SLEEP_1   = 0x07
+	MMA7660_PDET           = 0x09
+	MMA7660_PD             = 0x0A
+)
+
+type MMA7660Driver struct {
+	name       string
+	connection I2c
+}
+
+// NewMMA7660Driver creates a new driver with specified name and i2c interface
+func NewMMA7660Driver(a I2c, name string) *MMA7660Driver {
+	return &MMA7660Driver{
+		name:       name,
+		connection: a,
+	}
+}
+
+func (h *MMA7660Driver) Name() string                 { return h.name }
+func (h *MMA7660Driver) Connection() gobot.Connection { return h.connection.(gobot.Connection) }
+
+// Start initialized the mma7660
+func (h *MMA7660Driver) Start() (errs []error) {
+	if err := h.connection.I2cStart(mma7660Address); err != nil {
+		return []error{err}
+	}
+
+	if err := h.connection.I2cWrite(mma7660Address, []byte{MMA7660_MODE, MMA7660_STAND_BY}); err != nil {
+		return []error{err}
+	}
+
+	if err := h.connection.I2cWrite(mma7660Address, []byte{MMA7660_SR, MMA7660_AUTO_SLEEP_32}); err != nil {
+		return []error{err}
+	}
+
+	if err := h.connection.I2cWrite(mma7660Address, []byte{MMA7660_MODE, MMA7660_ACTIVE}); err != nil {
+		return []error{err}
+	}
+
+	return
+}
+
+// Halt returns true if devices is halted successfully
+func (h *MMA7660Driver) Halt() (errs []error) { return }
+
+// Acceleration returns the acceleration  of the provided x, y, z
+func (h *MMA7660Driver) Acceleration(x, y, z float64) (ax, ay, az float64) {
+	return x / 21.0, y / 21.0, z / 21.0
+}
+
+// XYZ returns the raw x,y and z axis from the  mma7660
+func (h *MMA7660Driver) XYZ() (x float64, y float64, z float64, err error) {
+	ret, err := h.connection.I2cRead(mma7660Address, 3)
+	if err != nil {
+		return
+	}
+
+	if len(ret) != 3 {
+		err = ErrNotEnoughBytes
+		return
+	}
+
+	for _, val := range ret {
+		if ((val >> 6) & 0x01) == 1 {
+			err = ErrNotReady
+			return
+		}
+	}
+
+	x = float64((int8(ret[0]) << 2)) / 4.0
+	y = float64((int8(ret[1]) << 2)) / 4.0
+	z = float64((int8(ret[2]) << 2)) / 4.0
+
+	return
+}