first commit

Software/flogo/activities/grovepiDHT/activity.go

@@ -0,0 +1,121 @@
+package grovepiDHT
+
+import (
+	"sync"
+	"time"
+	"unsafe"
+
+	"github.com/TIBCOSoftware/flogo-lib/core/activity"
+	"github.com/TIBCOSoftware/flogo-lib/logger"
+	"github.com/mrmorphic/hwio"
+)
+
+// log is the default package logger
+var log = logger.GetLogger("activity-tibco-GrovePiDHT")
+
+const (
+	ivPin         = "pin"
+	ovTemperature = "temperature"
+	ovHumidity    = "humidity"
+
+	//Cmd format
+	DHT_READ = 40
+)
+
+type GrovePi struct {
+	i2cmodule hwio.I2CModule
+	i2cDevice hwio.I2CDevice
+}
+
+// Activity is a Activity implementation
+type grovePiDWActivity struct {
+	sync.Mutex
+	metadata *activity.Metadata
+}
+
+// NewActivity creates a new Activity
+func NewActivity(metadata *activity.Metadata) activity.Activity {
+	return &grovePiDWActivity{metadata: metadata}
+}
+
+// Metadata implements activity.Activity.Metadata
+func (a *grovePiDWActivity) Metadata() *activity.Metadata {
+	return a.metadata
+}
+
+// Eval implements activity.Activity.Eval
+func (a *grovePiDWActivity) Eval(context activity.Context) (done bool, err error) {
+
+	var pin byte
+
+	log.Debug("Starting Pin DHT read")
+	if context.GetInput(ivPin) != nil {
+		pin = byte(context.GetInput(ivPin).(int))
+	}
+
+	var g *GrovePi
+	g = InitGrovePi(0x04)
+	defer g.CloseDevice()
+
+	t, h, err := g.ReadDHT(pin)
+	if err != nil {
+		log.Error("GrovePi ReadDHT Issue: ", err)
+	}
+
+	context.SetOutput(ovTemperature, t)
+	context.SetOutput(ovHumidity, h)
+
+	return true, nil
+}
+
+func InitGrovePi(address int) *GrovePi {
+	grovePi := new(GrovePi)
+	m, err := hwio.GetModule("i2c")
+	if err != nil {
+		log.Error("GrovePi :: could not get i2c module Error", err)
+		//fmt.Printf("could not get i2c module: %s\n", err)
+		return nil
+	}
+	grovePi.i2cmodule = m.(hwio.I2CModule)
+	grovePi.i2cmodule.Enable()
+
+	grovePi.i2cDevice = grovePi.i2cmodule.GetDevice(address)
+	return grovePi
+}
+
+func (grovePi GrovePi) CloseDevice() {
+	grovePi.i2cmodule.Disable()
+}
+
+func (grovePi *GrovePi) ReadDHT(pin byte) (float32, float32, error) {
+	b := []byte{DHT_READ, pin, 0, 0}
+	rawdata, err := grovePi.readDHTRawData(b)
+	if err != nil {
+		return 0, 0, err
+	}
+	temperatureData := rawdata[1:5]
+
+	tInt := int32(temperatureData[0]) | int32(temperatureData[1])<<8 | int32(temperatureData[2])<<16 | int32(temperatureData[3])<<24
+	t := (*(*float32)(unsafe.Pointer(&tInt)))
+
+	humidityData := rawdata[5:9]
+	humInt := int32(humidityData[0]) | int32(humidityData[1])<<8 | int32(humidityData[2])<<16 | int32(humidityData[3])<<24
+	h := (*(*float32)(unsafe.Pointer(&humInt)))
+	return t, h, nil
+}
+
+func (grovePi *GrovePi) readDHTRawData(cmd []byte) ([]byte, error) {
+
+	err := grovePi.i2cDevice.Write(1, cmd)
+	if err != nil {
+		return nil, err
+	}
+	time.Sleep(600 * time.Millisecond)
+	grovePi.i2cDevice.ReadByte(1)
+	time.Sleep(100 * time.Millisecond)
+	raw, err := grovePi.i2cDevice.Read(1, 9)
+	if err != nil {
+		return nil, err
+	}
+	return raw, nil
+}