WIP on MPL115A2

More WIP on mpl115a2
Even more WIP
This pumps out data

examples/firmata_mpl115a2.go

@@ -0,0 +1,34 @@
+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")
+	mpl115a2 := i2c.NewMPL115A2Driver(firmataAdaptor, "mpl115a2")
+
+	work := func() {
+		gobot.Every(1*time.Second, func() {
+			fmt.Println("Pressure", mpl115a2.Pressure)
+			fmt.Println("Temperature", mpl115a2.Temperature)
+		})
+	}
+
+	robot := gobot.NewRobot("mpl115a2Bot",
+		[]gobot.Connection{firmataAdaptor},
+		[]gobot.Device{mpl115a2},
+		work,
+	)
+
+	gbot.AddRobot(robot)
+
+	gbot.Start()
+}

platforms/i2c/mpl115a2_driver.go

@@ -0,0 +1,112 @@
+package i2c
+
+import (
+	"github.com/hybridgroup/gobot"
+
+	"bytes"
+	"encoding/binary"
+	"time"
+)
+
+const MPL115A2_REGISTER_PRESSURE_MSB = 0x00
+const MPL115A2_REGISTER_PRESSURE_LSB = 0x01
+const MPL115A2_REGISTER_TEMP_MSB = 0x02
+const MPL115A2_REGISTER_TEMP_LSB = 0x03
+const MPL115A2_REGISTER_A0_COEFF_MSB = 0x04
+const MPL115A2_REGISTER_A0_COEFF_LSB = 0x05
+const MPL115A2_REGISTER_B1_COEFF_MSB = 0x06
+const MPL115A2_REGISTER_B1_COEFF_LSB = 0x07
+const MPL115A2_REGISTER_B2_COEFF_MSB = 0x08
+const MPL115A2_REGISTER_B2_COEFF_LSB = 0x09
+const MPL115A2_REGISTER_C12_COEFF_MSB = 0x0A
+const MPL115A2_REGISTER_C12_COEFF_LSB = 0x0B
+const MPL115A2_REGISTER_STARTCONVERSION = 0x12
+
+type MPL115A2Driver struct {
+	gobot.Driver
+	A0          float32
+	B1          float32
+	B2          float32
+	C12         float32
+	Pressure    float32
+	Temperature float32
+}
+
+// NewMPL115A2Driver creates a new driver with specified name and i2c interface
+func NewMPL115A2Driver(a I2cInterface, name string) *MPL115A2Driver {
+	return &MPL115A2Driver{
+		Driver: *gobot.NewDriver(
+			name,
+			"MPL115A2Driver",
+			a.(gobot.AdaptorInterface),
+		),
+	}
+}
+
+// adaptor returns MPL115A2 adaptor
+func (h *MPL115A2Driver) adaptor() I2cInterface {
+	return h.Adaptor().(I2cInterface)
+}
+
+// Start writes initialization bytes and reads from adaptor
+// using specified interval to accelerometer andtemperature data
+func (h *MPL115A2Driver) Start() bool {
+	var temperature uint16
+	var pressure uint16
+	var pressureComp float32
+
+	h.initialization()
+
+	gobot.Every(h.Interval(), func() {
+		h.adaptor().I2cWrite([]byte{MPL115A2_REGISTER_STARTCONVERSION, 0})
+		<-time.After(5 * time.Millisecond)
+
+		h.adaptor().I2cWrite([]byte{MPL115A2_REGISTER_PRESSURE_MSB})
+		ret := h.adaptor().I2cRead(4)
+		if len(ret) == 4 {
+			buf := bytes.NewBuffer(ret)
+			binary.Read(buf, binary.BigEndian, &pressure)
+			binary.Read(buf, binary.BigEndian, &temperature)
+
+			temperature = temperature >> 6
+			pressure = pressure >> 6
+
+			pressureComp = float32(h.A0) + (float32(h.B1)+float32(h.C12)*float32(temperature))*float32(pressure) + float32(h.B2)*float32(temperature)
+			h.Pressure = (65.0/1023.0)*pressureComp + 50.0
+			h.Temperature = ((float32(temperature) - 498.0) / -5.35) + 25.0
+		}
+	})
+	return true
+}
+
+// Init returns true if device is initialized correctly
+func (h *MPL115A2Driver) Init() bool { return true }
+
+// Halt returns true if devices is halted successfully
+func (h *MPL115A2Driver) Halt() bool { return true }
+
+func (h *MPL115A2Driver) initialization() bool {
+	var coA0 int16
+	var coB1 int16
+	var coB2 int16
+	var coC12 int16
+
+	h.adaptor().I2cStart(0x60)
+	h.adaptor().I2cWrite([]byte{MPL115A2_REGISTER_A0_COEFF_MSB})
+	ret := h.adaptor().I2cRead(8)
+	buf := bytes.NewBuffer(ret)
+
+	binary.Read(buf, binary.BigEndian, &coA0)
+	binary.Read(buf, binary.BigEndian, &coB1)
+	binary.Read(buf, binary.BigEndian, &coB2)
+	binary.Read(buf, binary.BigEndian, &coC12)
+
+	coC12 = coC12 >> 2
+
+	h.A0 = float32(coA0) / 8.0
+	h.B1 = float32(coB1) / 8192.0
+	h.B2 = float32(coB2) / 16384.0
+	h.C12 = float32(coC12) / 4194304.0
+
+	return true
+}

platforms/i2c/mpl115a2_driver_test.go

@@ -0,0 +1,57 @@
+package i2c
+
+import (
+	"testing"
+
+	"github.com/hybridgroup/gobot"
+)
+
+// --------- HELPERS
+func initTestMPL115A2Driver() (driver *MPL115A2Driver) {
+	driver, _ = initTestMPL115A2DriverWithStubbedAdaptor()
+	return
+}
+
+func initTestMPL115A2DriverWithStubbedAdaptor() (*MPL115A2Driver, *i2cTestAdaptor) {
+	adaptor := newI2cTestAdaptor("adaptor")
+	return NewMPL115A2Driver(adaptor, "bot"), adaptor
+}
+
+// --------- TESTS
+
+func TestMPL115A2DriverDriver(t *testing.T) {
+	// Does it implement gobot.DriverInterface?
+	var _ gobot.DriverInterface = (*MPL115A2Driver)(nil)
+
+	// Does its adaptor implements the I2cInterface?
+	driver := initTestMPL115A2Driver()
+	var _ I2cInterface = driver.adaptor()
+}
+
+func TestNewMPL115A2Driver(t *testing.T) {
+	// Does it return a pointer to an instance of MPL115A2Driver?
+	var mpl interface{} = NewMPL115A2Driver(newI2cTestAdaptor("adaptor"), "bot")
+	_, ok := mpl.(*MPL115A2Driver)
+	if !ok {
+		t.Errorf("NewMPL115A2Driver() should have returned a *MPL115A2Driver")
+	}
+}
+
+// Methods
+func TestMPL115A2DriverStart(t *testing.T) {
+	mpl := initTestMPL115A2Driver()
+
+	gobot.Assert(t, mpl.Start(), true)
+}
+
+func TestMPL115A2DriverInit(t *testing.T) {
+	mpl := initTestMPL115A2Driver()
+
+	gobot.Assert(t, mpl.Init(), true)
+}
+
+func TestMPL115A2DriverHalt(t *testing.T) {
+	mpl := initTestMPL115A2Driver()
+
+	gobot.Assert(t, mpl.Halt(), true)
+}