diff --git a/pkg/cli/cli.go b/pkg/cli/cli.go
index 5b8bc78..f6bd434 100644
--- a/pkg/cli/cli.go
+++ b/pkg/cli/cli.go
@@ -1,23 +1,43 @@
 package cli
 
 import (
+	"errors"
 	"fmt"
 	"io"
+	"regexp"
 	"text/tabwriter"
 
 	"github.com/go-flucky/flucky/pkg/config"
 	"github.com/go-flucky/flucky/pkg/types"
 )
 
-// GetSensorsByMeasuredValues returns commulated list of sensors by measured values
-func GetSensorIDsByMeasuredValues(measuredValues []*types.MeasuredValue, cnf *config.Configuration) map[string]*types.Sensor {
+var (
+	errorMeasuredValueIDNotValid = errors.New("Measured value id is not a valid uuid")
+	errorSensorIDNotValid        = errors.New("Sensor id is not a valid uuid")
+
+	validUUID = regexp.MustCompile("^[0-9a-f]{8}-[0-9a-f]{4}-[0-9a-f]{4}-[0-9a-f]{4}-[0-9a-f]{12}$")
+)
+
+// GetSensorIDsByMeasuredValues returns commulated list of sensors by measured values
+func GetSensorIDsByMeasuredValues(measuredValues []*types.MeasuredValue, cnf *config.Configuration) (map[string]*types.Sensor, error) {
 	sensors := make(map[string]*types.Sensor)
 	for _, measuredValue := range measuredValues {
+
+		// check if sensor id is valid
+		if !validUUID.MatchString(measuredValue.ID) {
+			return nil, errorMeasuredValueIDNotValid
+		}
+
+		// check if sensor id is valid
+		if !validUUID.MatchString(measuredValue.SensorID) {
+			return nil, errorSensorIDNotValid
+		}
+
 		if _, ok := sensors[measuredValue.SensorID]; !ok {
 			sensors[measuredValue.SensorID] = cnf.GetSensorByID(measuredValue.SensorID)
 		}
 	}
-	return sensors
+	return sensors, nil
 }
 
 // PrintRGBLEDs displays a list with all configured RGBLEDs
@@ -86,9 +106,12 @@ func PrintSensors(cnf *config.Configuration, w io.Writer) error {
 }
 
 // PrintMeasuredValues displays a list of measured values
-func PrintMeasuredValues(measuredValues []*types.MeasuredValue, cnf *config.Configuration, w io.Writer) {
+func PrintMeasuredValues(measuredValues []*types.MeasuredValue, cnf *config.Configuration, w io.Writer) error {
 
-	sensors := GetSensorIDsByMeasuredValues(measuredValues, cnf)
+	sensors, err := GetSensorIDsByMeasuredValues(measuredValues, cnf)
+	if err != nil {
+		return err
+	}
 
 	// sort measured values for every sensor
 	orderedMeasuredValues := make(map[string][]*types.MeasuredValue)
@@ -130,4 +153,6 @@ func PrintMeasuredValues(measuredValues []*types.MeasuredValue, cnf *config.Conf
 		fmt.Fprint(tw, "\n")
 	}
 	tw.Flush()
+
+	return err
 }
diff --git a/pkg/cli/cli_test.go b/pkg/cli/cli_test.go
new file mode 100644
index 0000000..91b18d9
--- /dev/null
+++ b/pkg/cli/cli_test.go
@@ -0,0 +1,92 @@
+package cli
+
+import (
+	"testing"
+
+	"github.com/go-flucky/flucky/pkg/config"
+	"github.com/go-flucky/flucky/pkg/types"
+	"github.com/stretchr/testify/require"
+)
+
+type testCase struct {
+	goldenConfig         *config.Configuration
+	goldenMeasuredValues []*types.MeasuredValue
+	expectedSensors      map[string]*types.Sensor
+	expectedError        error
+}
+
+var (
+	goldenSensors = []*types.Sensor{
+		&types.Sensor{
+			ID: "5b7c08c8-ee2a-4f88-b796-83658caae09d",
+		},
+	}
+
+	goldenSensorMap = map[string]*types.Sensor{
+		"5b7c08c8-ee2a-4f88-b796-83658caae09d": goldenSensors[0],
+	}
+
+	goldenConfig = &config.Configuration{
+		Sensors: goldenSensors,
+	}
+
+	goldenMeasuredValues = []*types.MeasuredValue{
+		&types.MeasuredValue{
+			ID:       "4887b7cc-6b40-4293-bcc1-db1b5035a711",
+			SensorID: "5b7c08c8-ee2a-4f88-b796-83658caae09d",
+		},
+	}
+
+	measuredValuesWrongID = []*types.MeasuredValue{
+		&types.MeasuredValue{
+			ID:       "b2784dfb-c1a4-428d-8897-e09a18e7d94d",
+			SensorID: "5b7c08c8-ee2a-4f88-b796-83658caae09d",
+		},
+		&types.MeasuredValue{
+			ID:       "81ca1a60-dfea-42f3-a7",
+			SensorID: "5b7c08c8-ee2a-4f88-b796-83658caae09d",
+		},
+	}
+
+	measuredValuesWrongSensorID = []*types.MeasuredValue{
+		&types.MeasuredValue{
+			ID:       "b2784dfb-c1a4-428d-8897-e09a18e7d94d",
+			SensorID: "5b7c08c8-ee2a-4f88-b796-83658caae09d",
+		},
+		&types.MeasuredValue{
+			ID:       "b2784dfb-c1a4-428d-8897-e09a18e7d94d",
+			SensorID: "5b7c08c8-ee2a-4f88-b79",
+		},
+	}
+)
+
+func TestGetSensorIDsByMeasuredValues(t *testing.T) {
+	require := require.New(t)
+
+	testCases := []*testCase{
+		&testCase{
+			goldenConfig:         goldenConfig,
+			goldenMeasuredValues: goldenMeasuredValues,
+			expectedSensors:      goldenSensorMap,
+			expectedError:        nil,
+		},
+		&testCase{
+			goldenConfig:         goldenConfig,
+			goldenMeasuredValues: measuredValuesWrongID,
+			expectedSensors:      nil,
+			expectedError:        errorMeasuredValueIDNotValid,
+		},
+		&testCase{
+			goldenConfig:         goldenConfig,
+			goldenMeasuredValues: measuredValuesWrongSensorID,
+			expectedSensors:      nil,
+			expectedError:        errorSensorIDNotValid,
+		},
+	}
+
+	for _, testCase := range testCases {
+		actualSensors, err := GetSensorIDsByMeasuredValues(testCase.goldenMeasuredValues, testCase.goldenConfig)
+		require.EqualValues(testCase.expectedError, err, "Not the expected error")
+		require.EqualValues(testCase.expectedSensors, actualSensors, "Returned sensor list not expected")
+	}
+}
diff --git a/pkg/daemon/daemon.go b/pkg/daemon/daemon.go
index f5314c3..1f0ab54 100644
--- a/pkg/daemon/daemon.go
+++ b/pkg/daemon/daemon.go
@@ -84,6 +84,7 @@ func Start(cnf *config.Configuration, cleanCacheInterval time.Duration, compress
 						return
 					}
 					for _, measmeasuredValue := range measuredValues {
+						debugChannel <- fmt.Sprintf("%v: %v: %v", sensor.GetID(), measmeasuredValue.ValueType, measmeasuredValue.Value)
 						measuredValueChannel <- measmeasuredValue
 					}
 				}