diff --git a/constants.go b/constants.go
index 3b417a1..29ae098 100644
--- a/constants.go
+++ b/constants.go
@@ -17,7 +17,220 @@ const (
 	messageReceived = "received"
 
 	// Time (in seconds) to wait between performing read/send operations
-	dataReadPeriod  = 1
-	dataSendPeriod  = 10
+	dataReadPeriod  = 5
+	dataSendPeriod  = 30
 	heartbeatPeriod = 10
 )
+
+var metrics = [...]Metric{
+	{
+		"l1.l2.voltage",
+		0,
+		300,
+	},
+	{
+		"l2.l3.voltage",
+		0,
+		300,
+	},
+	{
+		"l3.l1.voltage",
+		0,
+		300,
+	},
+	{
+		"l1.l0.voltage",
+		0,
+		300,
+	},
+	{
+		"l2.l0.voltage",
+		0,
+		300,
+	},
+	{
+		"l3.l0.voltage",
+		0,
+		300,
+	},
+	{
+		"l1.current",
+		0,
+		300,
+	},
+	{
+		"l2.current",
+		0,
+		300,
+	},
+	{
+		"l3.current",
+		0,
+		300,
+	},
+	{
+		"frequency",
+		0,
+		3000,
+	},
+	{
+		"total.kw",
+		0,
+		1000000,
+	},
+	{
+		"rate.kw",
+		0,
+		100,
+	},
+	{
+		"total.pf",
+		0,
+		100,
+	},
+	{
+		"l1.kw",
+		0,
+		1000000,
+	},
+	{
+		"l1.pf",
+		0,
+		100,
+	},
+	{
+		"l2.kw",
+		0,
+		1000000,
+	},
+	{
+		"l2.pf",
+		0,
+		100,
+	},
+	{
+		"l3.kw",
+		0,
+		1000000,
+	},
+	{
+		"l3.pf",
+		0,
+		100,
+	},
+	{
+		"total.kvar",
+		0,
+		1000,
+	},
+	{
+		"l1.kvar",
+		0,
+		1000,
+	},
+	{
+		"l2.kvar",
+		0,
+		1000,
+	},
+	{
+		"l3.kvar",
+		0,
+		1000,
+	},
+	{
+		"total.kva",
+		0,
+		1000,
+	},
+	{
+		"l1.kva",
+		0,
+		1000,
+	},
+	{
+		"l2.kva",
+		0,
+		1000,
+	},
+	{
+		"l3.kva",
+		0,
+		1000,
+	},
+	{
+		"oil.pressure",
+		0,
+		200,
+	},
+	{
+		"coolant.temp",
+		0,
+		120,
+	},
+	{
+		"engine.rpm",
+		0,
+		3000,
+	},
+	{
+		"battery.voltage",
+		0,
+		100,
+	},
+	{
+		"fuel.pressure",
+		0,
+		1000,
+	},
+	{
+		"fuel.temp",
+		0,
+		200,
+	},
+	{
+		"fuel.rate",
+		0,
+		500,
+	},
+	{
+		"coolant.pressure",
+		0,
+		200,
+	},
+	{
+		"coolant.level",
+		0,
+		100,
+	},
+	{
+		"oil.temp",
+		0,
+		200,
+	},
+	{
+		"oil.level",
+		0,
+		100,
+	},
+	{
+		"crankcase.pressure",
+		0,
+		200,
+	},
+	{
+		"ambient.temp",
+		0,
+		200,
+	},
+	{
+		"intake.temp",
+		0,
+		200,
+	},
+	{
+		"intake.pressure",
+		0,
+		200,
+	},
+}
diff --git a/dataTypes.go b/dataTypes.go
index 93f9dc9..5e4369d 100644
--- a/dataTypes.go
+++ b/dataTypes.go
@@ -1,8 +1,8 @@
 package main
 
 type StampedReading struct {
-	Timestamp int         `json:"timestamp"`
-	Value     interface{} `json:"value"`
+	Timestamp int     `json:"timestamp"`
+	Value     float32 `json:"value"`
 }
 
 type Packet struct {
@@ -10,3 +10,9 @@ type Packet struct {
 	Kind    string `json:"kind"`
 	Message []byte `json:"message"`
 }
+
+type Metric struct {
+	Name   string
+	LBound float32
+	UBound float32
+}
diff --git a/server.go b/server.go
index 060ff4b..a7ab522 100644
--- a/server.go
+++ b/server.go
@@ -26,7 +26,7 @@ func dataSendLoop() {
 func dataReadLoop() { // Read data all day every day
 	for {
 		dataBuffer := make(map[string][]StampedReading)
-		reading := readData() // TODO: error handling
+		reading := readData()                // TODO: error handling
 		for metric, value := range reading { // Put our data in the buffer
 			if record, found := dataBuffer[metric]; !found {
 				dataBuffer[metric] = []StampedReading{value}
@@ -39,15 +39,17 @@ func dataReadLoop() { // Read data all day every day
 	}
 }
 
+var oldReadings = map[string]StampedReading{}
+
 func readData() map[string]StampedReading {
-	return map[string]StampedReading{
-		"oil.temp": {
-			Timestamp: int(time.Now().Unix()),
-			Value:     rand.Intn(150),
-		},
-		"fuel.temp": {
-			Timestamp: int(time.Now().Unix()),
-			Value:     rand.Intn(150),
-		},
+	newReadings := map[string]StampedReading{}
+	for _, element := range metrics {
+		newRead := StampedReading{
+			int(time.Now().Unix()),
+			0.875*oldReadings[element.Name].Value + 0.125*((rand.Float32()*(element.UBound-element.LBound))+element.LBound),
+		}
+		newReadings[element.Name] = newRead
 	}
+	oldReadings = newReadings
+	return newReadings
 }